.gitmodules

@@ -11,3 +11,6 @@
 [submodule "third_party/tracy"]
 	path = third_party/tracy
 	url = https://github.com/wolfpld/tracy.git
+[submodule "third_party/ImGuizmo"]
+	path = third_party/ImGuizmo
+	url = https://github.com/CedricGuillemet/ImGuizmo.git

editor/CMakeLists.txt

@@ -7,6 +7,7 @@ add_library(${NAME}_deps INTERFACE)
 
 target_link_libraries(${NAME}_deps INTERFACE
   ${ENGINE_NAME}
+  imguizmo
 )
 
 target_compile_features(${PROJECT_NAME} PUBLIC cxx_std_17)

editor/editor_camera.cpp

@@ -0,0 +1,99 @@
+#include "editor_camera.hpp"
+
+#include <algorithm>
+#include <cmath>
+
+namespace {
+
+constexpr float ORBIT_RADIANS_PER_PIXEL = 0.005f;
+const float MAX_PITCH = glm::radians(89.f);
+// Each wheel step moves this fraction of the way towards the pivot.
+constexpr float ZOOM_STEP = 0.1f;
+constexpr float MIN_DISTANCE = 0.05f;
+constexpr float MIN_ORTHO_HEIGHT = 0.01f;
+// Fly speed per unit of distance from the pivot, so it suits any scale.
+constexpr float FLY_SPEED = 1.5f;
+
+}  // namespace
+
+void EditorCamera::orbit(glm::vec2 pixels) {
+  if (mode != Mode::Scene3D) {
+    return;
+  }
+  yaw -= pixels.x * ORBIT_RADIANS_PER_PIXEL;
+  pitch = std::clamp(pitch - pixels.y * ORBIT_RADIANS_PER_PIXEL, -MAX_PITCH,
+                     MAX_PITCH);
+}
+
+void EditorCamera::pan(glm::vec2 pixels, float viewportHeight) {
+  if (viewportHeight <= 0.f) {
+    return;
+  }
+
+  // World units one pixel covers at the pivot's depth.
+  float unitsPerPixel =
+      mode == Mode::Scene3D
+          ? 2.f * distance * std::tan(fov / 2.f) / viewportHeight
+          : orthoHeight / viewportHeight;
+
+  // Screen y runs down, world y up. Dragging moves the scene with the mouse,
+  // so the camera moves the other way.
+  glm::vec3 offset{-pixels.x * unitsPerPixel, pixels.y * unitsPerPixel, 0.f};
+  pivot += mode == Mode::Scene3D ? getRotation() * offset : offset;
+}
+
+void EditorCamera::zoom(float steps) {
+  float scale = std::pow(1.f - ZOOM_STEP, steps);
+  if (mode == Mode::Scene3D) {
+    distance = std::max(distance * scale, MIN_DISTANCE);
+  } else {
+    orthoHeight = std::max(orthoHeight * scale, MIN_ORTHO_HEIGHT);
+  }
+}
+
+void EditorCamera::fly(glm::vec3 direction, float deltaTime) {
+  if (mode != Mode::Scene3D || direction == glm::vec3{0.f}) {
+    return;
+  }
+  float speed = FLY_SPEED * std::max(distance, 1.f);
+  pivot += getRotation() * glm::normalize(direction) * speed * deltaTime;
+}
+
+void EditorCamera::frame(glm::vec3 target, float radius) {
+  pivot = target;
+  radius = std::max(radius, 0.1f);
+  // Far enough that the sphere fits in the vertical field of view.
+  distance = radius / std::sin(fov / 2.f);
+  orthoHeight = radius * 2.5f;
+}
+
+sophia::TransformComponent EditorCamera::getTransform() const {
+  sophia::TransformComponent transform;
+  if (mode == Mode::Scene3D) {
+    transform.rotation = getRotation();
+    transform.position =
+        pivot + transform.rotation * glm::vec3{0.f, 0.f, distance};
+  } else {
+    transform.position = pivot;
+  }
+  return transform;
+}
+
+sophia::CameraComponent EditorCamera::getCamera() const {
+  sophia::CameraComponent camera;
+  if (mode == Mode::Scene3D) {
+    camera.projection = sophia::CameraComponent::Projection::Perspective;
+    camera.perspective.fov = fov;
+    // Room to zoom far out without the scene clipping.
+    camera.perspective.farPlane = 1000.f;
+  } else {
+    camera.projection = sophia::CameraComponent::Projection::Orthographic;
+    camera.ortho.height = orthoHeight;
+  }
+  return camera;
+}
+
+glm::quat EditorCamera::getRotation() const {
+  return glm::angleAxis(yaw, glm::vec3{0.f, 1.f, 0.f}) *
+         glm::angleAxis(pitch, glm::vec3{1.f, 0.f, 0.f});
+}

editor/editor_camera.hpp

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <sophia/components.hpp>
+#include <sophia/math.hpp>
+
+/**
+ * The Scene panel's camera. Not part of any scene the editor edits, and never
+ * saved with one.
+ *
+ * In 3D it orbits a pivot point at some distance; in 2D it looks straight
+ * down -Z at the pivot through an orthographic projection, like a 2D game
+ * camera.
+ */
+class EditorCamera {
+ public:
+  enum class Mode { Scene3D, Scene2D };
+
+  Mode mode = Mode::Scene3D;
+
+  // Turns around the pivot by a mouse movement in pixels. 3D only.
+  void orbit(glm::vec2 pixels);
+  // Moves the pivot so the scene follows a mouse movement in pixels across a
+  // viewport `viewportHeight` pixels tall.
+  void pan(glm::vec2 pixels, float viewportHeight);
+  // Moves in (positive) or out by mouse wheel steps.
+  void zoom(float steps);
+  // Moves the pivot along the camera's axes: x right, y up, z backwards.
+  // `direction` needn't be normalized. 3D only.
+  void fly(glm::vec3 direction, float deltaTime);
+  // Centers on `target`, backing off enough to see a sphere of `radius`.
+  void frame(glm::vec3 target, float radius);
+
+  sophia::TransformComponent getTransform() const;
+  sophia::CameraComponent getCamera() const;
+
+ private:
+  glm::quat getRotation() const;
+
+  glm::vec3 pivot{0.f, 0.f, 0.f};
+
+  // 3D: looking at the pivot from in front, a little to the right and above.
+  float yaw = glm::radians(30.f);
+  float pitch = glm::radians(-25.f);
+  float distance = 8.f;
+  float fov = glm::radians(60.f);
+
+  // 2D: world units visible from the bottom of the view to the top.
+  float orthoHeight = 10.f;
+};

editor/editor_context.hpp

@@ -0,0 +1,89 @@
+#pragma once
+
+#include <sophia/entity.hpp>
+#include <sophia/handles.hpp>
+#include <sophia/scene.hpp>
+#include <sophia/scene_registry.hpp>
+#include <sophia/scene_view_registry.hpp>
+#include <string>
+#include <vector>
+
+/**
+ * What the editor is working on, shared by its panels. Panels read it every
+ * frame instead of holding on to a scene, so switching scenes is one call.
+ */
+class EditorContext {
+ public:
+  // A scene the editor has open, and can switch to.
+  struct OpenScene {
+    sophia::SceneHandle handle;
+    std::string name;
+  };
+
+  explicit EditorContext(sophia::SceneRegistry& scenes) : scenes{scenes} {}
+
+  // Creates an open scene with a "Main Camera", without switching to it.
+  sophia::SceneHandle createScene(std::string name) {
+    sophia::SceneHandle handle = scenes.create();
+    scenes.get(handle).createCamera("Main Camera");
+    openScenes.push_back({handle, std::move(name)});
+    return handle;
+  }
+
+  const std::vector<OpenScene>& getOpenScenes() const { return openScenes; }
+
+  // Null if `handle` isn't an open scene.
+  const std::string* getSceneName(sophia::SceneHandle handle) const {
+    for (const OpenScene& open : openScenes) {
+      if (open.handle == handle) {
+        return &open.name;
+      }
+    }
+    return nullptr;
+  }
+
+  void renameScene(sophia::SceneHandle handle, std::string name) {
+    for (OpenScene& open : openScenes) {
+      if (open.handle == handle) {
+        open.name = std::move(name);
+      }
+    }
+  }
+
+  bool hasScene() const { return scenes.isAlive(activeScene); }
+  sophia::SceneHandle getSceneHandle() const { return activeScene; }
+  sophia::Scene& getScene() { return scenes.get(activeScene); }
+
+  // Also clears the selection, which belonged to the previous scene.
+  void setScene(sophia::SceneHandle handle) {
+    activeScene = handle;
+    selected = {};
+  }
+
+  // Null when nothing is selected. Always an entity of the active scene.
+  sophia::Entity selected;
+
+ private:
+  sophia::SceneRegistry& scenes;
+  sophia::SceneHandle activeScene = sophia::INVALID_HANDLE;
+  // Kept open even when not active: with no saving yet, closing one would
+  // lose it.
+  std::vector<OpenScene> openScenes;
+};
+
+// Points `view` at the context's active scene, and renders it only while
+// there is one and its panel is `shown`. Call every frame from the panel that
+// owns the view.
+inline void syncSceneView(EditorContext& context,
+                          sophia::SceneViewRegistry& sceneViews,
+                          sophia::SceneViewHandle view, bool shown) {
+  bool enabled = shown && context.hasScene();
+  const sophia::SceneView& current = sceneViews.peek(view);
+  // get() re-sorts the render queue, so only use it when something changed.
+  if (current.enabled != enabled ||
+      (context.hasScene() && current.scene != context.getSceneHandle())) {
+    sophia::SceneView& updated = sceneViews.get(view);
+    updated.enabled = enabled;
+    updated.scene = context.getSceneHandle();
+  }
+}

editor/main.cpp

@@ -1,49 +1,86 @@
-#include <iostream>
 #include <sophia/application.hpp>
 #include <sophia/components.hpp>
 #include <sophia/entity.hpp>
+#include <sophia/primitives.hpp>
+#include <vector>
 
+#include "editor_context.hpp"
 #include "panels/asset_browser_panel.hpp"
+#include "panels/game_panel.hpp"
 #include "panels/inspector_panel.hpp"
 #include "panels/scene_hierarchy_panel.hpp"
-#include "panels/viewport_panel.hpp"
+#include "panels/scene_panel.hpp"
+#include "utilities/logger.hpp"
 
 class Editor : public sophia::Application {
  public:
   Editor() : Application{{.width = 750, .height = 1000, .name = "Editor"}} {}
 
   void onCreate() override {
-    std::cout << "Editor created" << std::endl;
+    log("Editor created");
 
     debugUI().show();
 
     textures.emplace_back("Checker", createCheckerTexture());
+    cubeMesh = createShadedCube();
 
-    sophia::SceneHandle sceneHandle = scenes().create();
+    sophia::SceneHandle sceneHandle = context.createScene("Demo");
-    sophia::Scene& scene = scenes().get(sceneHandle);
+    createDemoScene(scenes().get(sceneHandle));
-    createDemoScene(scene);
+    context.setScene(sceneHandle);
 
-    panels().emplace<SceneHierarchyPanel>(scene, selected);
+    // The editor's own scene, never edited or rendered. It holds the camera
-    panels().emplace<InspectorPanel>(selected, textures);
+    // the Scene panel looks through, which a SceneView may take from any
-    panels().emplace<AssetBrowserPanel>();
+    // scene.
+    sophia::SceneHandle editorSceneHandle = scenes().create();
+    sophia::Entity editorCamera =
+        scenes().get(editorSceneHandle).createCamera("Editor Camera");
+
+    // Views start without a scene; their panels point them at the active
+    // scene each frame.
     sophia::RenderTargetHandle sceneTarget =
         resources().create<sophia::RenderTarget>();
-    sceneViews().create({.scene = sceneHandle, .target = sceneTarget});
+    sophia::SceneViewHandle sceneView = sceneViews().create(
-    panels().emplace<ViewportPanel>(ui(), sceneTarget, scene, selected);
+        {.target = sceneTarget, .camera = editorCamera, .enabled = false});
+
+    // No camera: the Game panel shows the scene through its active one.
+    sophia::RenderTargetHandle gameTarget =
+        resources().create<sophia::RenderTarget>();
+    sophia::SceneViewHandle gameView =
+        sceneViews().create({.target = gameTarget, .enabled = false});
+
+    panels().emplace<SceneHierarchyPanel>(context, cubeMesh);
+    panels().emplace<InspectorPanel>(context, textures);
+    panels().emplace<AssetBrowserPanel>();
+    viewPanels.push_back(
+        {panels().emplace<ScenePanel>(ui(), resources(), context, sceneViews(),
+                                      sceneView, sceneTarget, editorCamera),
+         sceneView});
+    viewPanels.push_back(
+        {panels().emplace<GamePanel>(ui(), context, sceneViews(), gameView,
+                                     gameTarget),
+         gameView});
 
     panels().setDefaultLayout(
         {.left = {"Scene Hierarchy"},
          .right = {"Inspector", "Frame Stats", "PanelRegistry"},
          .bottom = {"Asset Browser", "Console"},
-         .center = {"Viewport"}});
+         .center = {"Scene", "Game"}});
   }
 
-  void onUpdate(const sophia::FrameInfo& frameInfo) override {}
+  void onUpdate(const sophia::FrameInfo& frameInfo) override {
+    // A closed panel's onUpdate() doesn't run, so it can't stop its view
+    // rendering itself.
+    for (const ViewPanel& viewPanel : viewPanels) {
+      if (!panels().get(viewPanel.panel).isVisible() &&
+          sceneViews().peek(viewPanel.view).enabled) {
+        sceneViews().get(viewPanel.view).enabled = false;
+      }
+    }
+  }
 
  private:
+  // Adds to a new scene, which already has a camera.
   void createDemoScene(sophia::Scene& scene) {
-    scene.createCamera("Main Camera");
-
     sophia::Entity checker = scene.createEntity("Checker");
     checker.getComponent<sophia::TransformComponent>().position = {-1.5f, 0.f,
                                                                    0.f};
@@ -63,6 +100,27 @@ class Editor : public sophia::Application {
         sophia::SpriteComponent{.color = {0.25f, 0.45f, 0.95f, 0.6f},
                                 .size = {2.f, 2.f},
                                 .sortOrder = 1});
+
+    sophia::Entity cube = scene.createEntity("Cube");
+    auto& cubeTransform = cube.getComponent<sophia::TransformComponent>();
+    cubeTransform.position = {0.f, 2.5f, 0.f};
+    cubeTransform.rotation =
+        glm::quat{glm::radians(glm::vec3{30.f, 45.f, 0.f})};
+    cube.addComponent<sophia::MeshComponent>(sophia::MeshComponent{
+        .handle = cubeMesh, .color = {0.4f, 0.8f, 0.5f, 1.f}});
+  }
+
+  // Meshes are unlit, so a plain cube is a flat silhouette. Bake a fixed
+  // light into its vertex colors so its faces read in 3D until there's real
+  // lighting; MeshComponent::color still tints it.
+  sophia::MeshHandle createShadedCube() {
+    const glm::vec3 lightDirection = glm::normalize(glm::vec3{0.4f, 1.f, 0.7f});
+    sophia::MeshData data = sophia::primitives::cube();
+    for (sophia::MeshVertex& vertex : data.vertices) {
+      float light = glm::dot(vertex.normal, lightDirection) * 0.5f + 0.5f;
+      vertex.color = glm::vec4{glm::vec3{0.35f + 0.65f * light}, 1.f};
+    }
+    return resources().create<sophia::Mesh>(data);
   }
 
   sophia::TextureHandle createCheckerTexture() {
@@ -79,8 +137,17 @@ class Editor : public sophia::Application {
     return resources().create<sophia::Texture>(SIZE, SIZE, std::move(pixels));
   }
 
-  sophia::Entity selected;
+  // A panel showing a scene view, which should only render while the panel
+  // is on screen.
+  struct ViewPanel {
+    sophia::PanelHandle panel;
+    sophia::SceneViewHandle view;
+  };
+
+  EditorContext context{scenes()};
+  std::vector<ViewPanel> viewPanels;
   InspectorPanel::TextureList textures;
+  sophia::MeshHandle cubeMesh;
 };
 
 SOPHIA_MAIN(Editor)

editor/panels/game_panel.cpp

@@ -0,0 +1,20 @@
+#include "game_panel.hpp"
+
+#include <imgui.h>
+
+void GamePanel::onUpdate(const sophia::FrameInfo&) {
+  syncSceneView(context, sceneViews, view, isShown());
+
+  if (!context.hasScene()) {
+    ImGui::TextDisabled("No scene open");
+    return;
+  }
+
+  const ImVec2 origin = ImGui::GetCursorScreenPos();
+  ui.image(target);
+
+  if (!context.getScene().getActiveCamera()) {
+    ImGui::SetCursorScreenPos(ImVec2(origin.x + 8.0f, origin.y + 8.0f));
+    ImGui::TextDisabled("The scene has no active camera");
+  }
+}

editor/panels/game_panel.hpp

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <sophia/frame_info.hpp>
+#include <sophia/handles.hpp>
+#include <sophia/scene_view_registry.hpp>
+#include <sophia/ui/panel.hpp>
+#include <sophia/ui/ui.hpp>
+
+#include "../editor_context.hpp"
+
+/**
+ * Shows the active scene through its own active camera: what the game will
+ * see.
+ */
+class GamePanel : public sophia::Panel {
+ public:
+  // Renders into `target` through `view`, a SceneView with no camera of its
+  // own that this panel keeps pointed at the active scene.
+  GamePanel(sophia::UI& ui, EditorContext& context,
+            sophia::SceneViewRegistry& sceneViews, sophia::SceneViewHandle view,
+            sophia::RenderTargetHandle target)
+      : Panel{{.name = "Game",
+               .windowFlags = ImGuiWindowFlags_NoScrollbar |
+                              ImGuiWindowFlags_NoScrollWithMouse}},
+        ui{ui},
+        context{context},
+        sceneViews{sceneViews},
+        view{view},
+        target{target} {}
+
+  void onUpdate(const sophia::FrameInfo& frameInfo) override;
+
+ private:
+  sophia::UI& ui;
+  EditorContext& context;
+  sophia::SceneViewRegistry& sceneViews;
+  sophia::SceneViewHandle view;
+  sophia::RenderTargetHandle target;
+};

editor/panels/inspector_panel.cpp

@@ -6,6 +6,7 @@
 #include <sophia/components.hpp>
 
 void InspectorPanel::onUpdate(const sophia::FrameInfo&) {
+  selected = context.selected;
   if (!selected) {
     ImGui::TextDisabled("No entity selected");
     return;
@@ -16,6 +17,7 @@ void InspectorPanel::onUpdate(const sophia::FrameInfo&) {
   drawTransform();
   drawCamera();
   drawSprite();
+  drawMesh();
 
   ImGui::Separator();
   drawAddComponent();
@@ -40,11 +42,13 @@ void InspectorPanel::drawTransform() {
   auto& transform = selected.getComponent<sophia::TransformComponent>();
   ImGui::DragFloat3("Position", &transform.position.x, 0.1f);
 
-  // 2D only: edits rotation around Z and drops any X/Y rotation.
+  // Euler angles in degrees, recomputed from the quaternion every frame.
-  float degrees = glm::degrees(glm::eulerAngles(transform.rotation).z);
+  // Near 90 degrees of pitch the angles can jump between equivalent values
-  if (ImGui::DragFloat("Rotation", &degrees, 1.0f)) {
+  // while dragging.
-    transform.rotation =
+  // TODO: keep each entity's edited angles, or replace with gizmo rotation.
-        glm::angleAxis(glm::radians(degrees), glm::vec3{0.f, 0.f, 1.f});
+  glm::vec3 degrees = glm::degrees(glm::eulerAngles(transform.rotation));
+  if (ImGui::DragFloat3("Rotation", &degrees.x, 1.0f)) {
+    transform.rotation = glm::quat{glm::radians(degrees)};
   }
 
   ImGui::DragFloat3("Scale", &transform.scale.x, 0.1f);
@@ -118,6 +122,29 @@ void InspectorPanel::drawSprite() {
   }
 }
 
+void InspectorPanel::drawMesh() {
+  if (!selected.hasComponent<sophia::MeshComponent>()) {
+    return;
+  }
+
+  bool open = true;
+  if (!ImGui::CollapsingHeader("Mesh", &open, ImGuiTreeNodeFlags_DefaultOpen)) {
+    if (!open) {
+      selected.removeComponent<sophia::MeshComponent>();
+    }
+    return;
+  }
+
+  auto& mesh = selected.getComponent<sophia::MeshComponent>();
+  // TODO: pick the mesh once assets have names.
+  ImGui::Text("Mesh: %u", static_cast<sophia::u32>(mesh.handle.index));
+  ImGui::ColorEdit3("Color", &mesh.color.x);
+
+  if (!open) {
+    selected.removeComponent<sophia::MeshComponent>();
+  }
+}
+
 void InspectorPanel::drawAddComponent() {
   if (ImGui::Button("Add Component")) {
     ImGui::OpenPopup("AddComponent");

editor/panels/inspector_panel.hpp

@@ -8,14 +8,16 @@
 #include <utility>
 #include <vector>
 
+#include "../editor_context.hpp"
+
 class InspectorPanel : public sophia::Panel {
  public:
   // Stand-in for an asset browser: the textures a sprite can pick from.
   using TextureList =
       std::vector<std::pair<std::string, sophia::TextureHandle>>;
 
-  InspectorPanel(sophia::Entity& selected, const TextureList& textures)
+  InspectorPanel(EditorContext& context, const TextureList& textures)
-      : Panel{{.name = "Inspector"}}, selected{selected}, textures{textures} {}
+      : Panel{{.name = "Inspector"}}, context{context}, textures{textures} {}
 
   void onUpdate(const sophia::FrameInfo& frameInfo) override;
 
@@ -24,8 +26,11 @@ class InspectorPanel : public sophia::Panel {
   void drawTransform();
   void drawCamera();
   void drawSprite();
+  void drawMesh();
   void drawAddComponent();
 
-  sophia::Entity& selected;
+  EditorContext& context;
+  // The selected entity, for the duration of onUpdate().
+  sophia::Entity selected;
   const TextureList& textures;
 };

editor/panels/scene_hierarchy_panel.cpp

@@ -2,18 +2,37 @@
 
 #include <imgui.h>
 
+#include <cstdio>
 #include <sophia/components.hpp>
+#include <string>
 
 void SceneHierarchyPanel::onUpdate(const sophia::FrameInfo&) {
+  drawSceneSelector();
+  ImGui::Separator();
+
+  if (!context.hasScene()) {
+    ImGui::TextDisabled("No scene open");
+    return;
+  }
+
+  sophia::Scene& scene = context.getScene();
+  sophia::Entity& selected = context.selected;
+
   if (ImGui::Button("+ Sprite")) {
     selected = scene.createEntity("Sprite");
     selected.addComponent<sophia::SpriteComponent>();
   }
+  ImGui::SameLine();
+  if (ImGui::Button("+ Cube")) {
+    selected = scene.createEntity("Cube");
+    selected.addComponent<sophia::MeshComponent>(
+        sophia::MeshComponent{.handle = cubeMesh});
+  }
 
   ImGui::Separator();
 
   // Flat for now: there is no parent/child component yet.
-  scene.forEachEntity([this](sophia::Entity entity) {
+  scene.forEachEntity([&selected](sophia::Entity entity) {
     ImGuiTreeNodeFlags flags = ImGuiTreeNodeFlags_Leaf |
                                ImGuiTreeNodeFlags_NoTreePushOnOpen |
                                ImGuiTreeNodeFlags_SpanAvailWidth;
@@ -30,3 +49,86 @@ void SceneHierarchyPanel::onUpdate(const sophia::FrameInfo&) {
     ImGui::PopID();
   });
 }
+
+namespace {
+// See SceneHierarchyPanel::renameFocusFrames.
+constexpr int RENAME_FOCUS_FRAMES = 2;
+}  // namespace
+
+void SceneHierarchyPanel::drawSceneSelector() {
+  // Leave room for the button: its label, its padding, and the gap to it.
+  constexpr const char* ADD_SCENE_LABEL = "Add Scene";
+  const ImGuiStyle& style = ImGui::GetStyle();
+  ImGui::SetNextItemWidth(-(ImGui::CalcTextSize(ADD_SCENE_LABEL).x +
+                            style.FramePadding.x * 2.f + style.ItemSpacing.x));
+
+  const std::string* current = context.getSceneName(context.getSceneHandle());
+  bool startRename = false;
+
+  if (renamingScene && current) {
+    drawSceneRename();
+  } else {
+    renamingScene = false;
+    if (ImGui::BeginCombo("##scene", current ? current->c_str() : "No scene")) {
+      for (const EditorContext::OpenScene& open : context.getOpenScenes()) {
+        ImGui::PushID(static_cast<int>(open.handle.index));
+        bool isCurrent = open.handle == context.getSceneHandle();
+        if (ImGui::Selectable(open.name.c_str(), isCurrent) && !isCurrent) {
+          context.setScene(open.handle);
+        }
+        ImGui::PopID();
+      }
+      ImGui::EndCombo();
+    }
+
+    if (current && ImGui::BeginPopupContextItem("##sceneMenu")) {
+      startRename = ImGui::MenuItem("Rename", "F2");
+      ImGui::EndPopup();
+    }
+    startRename = startRename || (current && ImGui::IsWindowFocused() &&
+                                  !ImGui::GetIO().WantTextInput &&
+                                  ImGui::IsKeyPressed(ImGuiKey_F2));
+  }
+
+  ImGui::SameLine();
+  if (ImGui::Button(ADD_SCENE_LABEL)) {
+    std::string name = "Untitled " + std::to_string(++this->untitledSceneCount);
+    context.setScene(context.createScene(std::move(name)));
+    startRename = false;
+  }
+
+  if (startRename) {
+    renamingScene = true;
+    renameFocusFrames = RENAME_FOCUS_FRAMES;
+    std::snprintf(renameBuffer.data(), renameBuffer.size(), "%s",
+                  current->c_str());
+  }
+}
+
+void SceneHierarchyPanel::drawSceneRename() {
+  if (renameFocusFrames == RENAME_FOCUS_FRAMES) {
+    ImGui::SetKeyboardFocusHere();
+  }
+
+  ImGui::InputText("##sceneName", renameBuffer.data(), renameBuffer.size(),
+                   ImGuiInputTextFlags_AutoSelectAll);
+
+  bool active = ImGui::IsItemActive();
+  if (active) {
+    renameFocusFrames = 0;
+  } else if (renameFocusFrames > 0) {
+    renameFocusFrames--;
+    return;
+  }
+
+  // Escape reverts the text before deactivating, so committing whatever is
+  // left when the field closes covers Enter, clicking away and Escape alike.
+  if (!active) {
+    std::string name = renameBuffer.data();
+    // Keep the old name rather than leave the scene nameless.
+    if (name.find_first_not_of(' ') != std::string::npos) {
+      context.renameScene(context.getSceneHandle(), std::move(name));
+    }
+    renamingScene = false;
+  }
+}

editor/panels/scene_hierarchy_panel.hpp

@@ -1,20 +1,38 @@
 #pragma once
 
-#include <sophia/entity.hpp>
+#include <array>
 #include <sophia/frame_info.hpp>
-#include <sophia/scene.hpp>
+#include <sophia/handles.hpp>
 #include <sophia/ui/panel.hpp>
 
+#include "../editor_context.hpp"
+
 class SceneHierarchyPanel : public sophia::Panel {
  public:
-  SceneHierarchyPanel(sophia::Scene& scene, sophia::Entity& selected)
+  // `cubeMesh` is what "+ Cube" gives new entities.
+  SceneHierarchyPanel(EditorContext& context, sophia::MeshHandle cubeMesh)
       : Panel{{.name = "Scene Hierarchy", .locked = true}},
-        scene{scene},
+        context{context},
-        selected{selected} {}
+        cubeMesh{cubeMesh} {}
 
   void onUpdate(const sophia::FrameInfo& frameInfo) override;
 
  private:
-  sophia::Scene& scene;
+  // Switches between open scenes, renames the active one, and creates new
-  sophia::Entity& selected;
+  // ones.
+  void drawSceneSelector();
+  // Replaces the selector with a text field editing the active scene's name.
+  void drawSceneRename();
+
+  EditorContext& context;
+  sophia::MeshHandle cubeMesh;
+  // For naming new scenes "Untitled 1", "Untitled 2", ...
+  int untitledSceneCount = 0;
+
+  // Set while the scene selector is a text field for renaming.
+  bool renamingScene = false;
+  // Frames the text field has left to become active after renaming starts;
+  // focus can take a frame to land. If it never does, renaming ends.
+  int renameFocusFrames = 0;
+  std::array<char, 128> renameBuffer{};
 };

editor/panels/scene_panel.cpp

@@ -0,0 +1,603 @@
+#include "scene_panel.hpp"
+
+#include <imgui.h>
+// After imgui.h, which it relies on.
+#include <ImGuizmo.h>
+
+#include <algorithm>
+#include <array>
+#include <cmath>
+#include <glm/gtc/type_ptr.hpp>
+#include <limits>
+#include <optional>
+#include <sophia/aabb.hpp>
+#include <sophia/components.hpp>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+namespace {
+
+// Corners of the unit quad a SpriteComponent's model matrix maps to world.
+constexpr std::array<glm::vec2, 4> UNIT_QUAD{
+    glm::vec2{0.f, 0.f}, glm::vec2{1.f, 0.f}, glm::vec2{1.f, 1.f},
+    glm::vec2{0.f, 1.f}};
+
+const ImU32 SELECTION_COLOR = IM_COL32(255, 170, 40, 255);
+
+// Holding Ctrl snaps the gizmo to these steps.
+constexpr float TRANSLATE_SNAP = 0.5f;
+constexpr float ROTATE_SNAP_DEGREES = 15.f;
+constexpr float SCALE_SNAP = 0.1f;
+
+// Writes a matrix built from a translation, rotation and scale (no shear)
+// back into `transform`. A mirroring matrix comes back with a negative x
+// scale.
+void decompose(const glm::mat4& matrix, sophia::TransformComponent& transform) {
+  transform.position = glm::vec3{matrix[3]};
+
+  glm::vec3 scale{glm::length(glm::vec3{matrix[0]}),
+                  glm::length(glm::vec3{matrix[1]}),
+                  glm::length(glm::vec3{matrix[2]})};
+  if (glm::determinant(glm::mat3{matrix}) < 0.f) {
+    scale.x = -scale.x;
+  }
+  transform.scale = scale;
+
+  // A zero scale loses the axis, and with it the rotation; keep the old one.
+  if (scale.x == 0.f || scale.y == 0.f || scale.z == 0.f) {
+    return;
+  }
+  glm::mat3 rotation{glm::vec3{matrix[0]} / scale.x,
+                     glm::vec3{matrix[1]} / scale.y,
+                     glm::vec3{matrix[2]} / scale.z};
+  transform.rotation = glm::normalize(glm::quat_cast(rotation));
+}
+
+// How far along a ray (from `origin`, along the normalized `direction`) it
+// enters `bounds` placed by `model`, or null if it misses. A ray starting
+// inside hits at 0.
+std::optional<float> intersectBox(const glm::vec3& origin,
+                                  const glm::vec3& direction,
+                                  const glm::mat4& model,
+                                  const sophia::AABB& bounds) {
+  if (glm::determinant(model) == 0.f) {
+    return std::nullopt;
+  }
+
+  // Test in the box's space, where it's axis-aligned. The direction isn't
+  // renormalized, so distances along it are still world distances.
+  glm::mat4 inverse = glm::inverse(model);
+  glm::vec3 localOrigin = glm::vec3{inverse * glm::vec4{origin, 1.f}};
+  glm::vec3 localDirection = glm::vec3{inverse * glm::vec4{direction, 0.f}};
+
+  float enter = 0.f;
+  float exit = std::numeric_limits<float>::infinity();
+  for (int axis = 0; axis < 3; axis++) {
+    if (std::abs(localDirection[axis]) < 1e-8f) {
+      // Parallel to this pair of faces: hits only if already between them.
+      if (localOrigin[axis] < bounds.min[axis] ||
+          localOrigin[axis] > bounds.max[axis]) {
+        return std::nullopt;
+      }
+      continue;
+    }
+
+    float toMin = (bounds.min[axis] - localOrigin[axis]) / localDirection[axis];
+    float toMax = (bounds.max[axis] - localOrigin[axis]) / localDirection[axis];
+    if (toMin > toMax) {
+      std::swap(toMin, toMax);
+    }
+    enter = std::max(enter, toMin);
+    exit = std::min(exit, toMax);
+    if (enter > exit) {
+      return std::nullopt;
+    }
+  }
+  return enter;
+}
+
+// How far along a ray it hits the unit quad (0, 0)-(1, 1) in the XY plane,
+// placed by `model`, or null if it misses.
+std::optional<float> intersectQuad(const glm::vec3& origin,
+                                   const glm::vec3& direction,
+                                   const glm::mat4& model) {
+  if (glm::determinant(model) == 0.f) {
+    return std::nullopt;
+  }
+
+  glm::mat4 inverse = glm::inverse(model);
+  glm::vec3 localOrigin = glm::vec3{inverse * glm::vec4{origin, 1.f}};
+  glm::vec3 localDirection = glm::vec3{inverse * glm::vec4{direction, 0.f}};
+  // Edge on to the quad.
+  if (std::abs(localDirection.z) < 1e-8f) {
+    return std::nullopt;
+  }
+
+  float distance = -localOrigin.z / localDirection.z;
+  if (distance < 0.f) {
+    return std::nullopt;
+  }
+  glm::vec3 hit = localOrigin + distance * localDirection;
+  if (hit.x < 0.f || hit.x > 1.f || hit.y < 0.f || hit.y > 1.f) {
+    return std::nullopt;
+  }
+  return distance;
+}
+
+}  // namespace
+
+ImVec2 ScenePanel::ViewportTransform::clipToScreen(
+    const glm::vec4& clip) const {
+  glm::vec2 ndc = glm::vec2{clip} / clip.w;
+  // Vulkan NDC has +y pointing down, same as the screen.
+  return {origin.x + (ndc.x * 0.5f + 0.5f) * size.x,
+          origin.y + (ndc.y * 0.5f + 0.5f) * size.y};
+}
+
+std::optional<ImVec2> ScenePanel::ViewportTransform::worldToScreen(
+    const glm::vec3& world) const {
+  glm::vec4 clip = viewProjection * glm::vec4{world, 1.f};
+  if (clip.w <= 0.f) {
+    return std::nullopt;
+  }
+  return clipToScreen(clip);
+}
+
+glm::vec2 ScenePanel::ViewportTransform::screenToWorld(
+    const ImVec2& screen) const {
+  glm::vec2 ndc{(screen.x - origin.x) / size.x * 2.f - 1.f,
+                (screen.y - origin.y) / size.y * 2.f - 1.f};
+  glm::vec4 world = inverseViewProjection * glm::vec4{ndc, 0.f, 1.f};
+  return glm::vec2{world} / world.w;
+}
+
+ScenePanel::Ray ScenePanel::ViewportTransform::screenToRay(
+    const ImVec2& screen) const {
+  glm::vec2 ndc{(screen.x - origin.x) / size.x * 2.f - 1.f,
+                (screen.y - origin.y) / size.y * 2.f - 1.f};
+  // Depth runs 0 at the near plane to 1 at the far one.
+  glm::vec4 nearPoint = inverseViewProjection * glm::vec4{ndc, 0.f, 1.f};
+  glm::vec4 farPoint = inverseViewProjection * glm::vec4{ndc, 1.f, 1.f};
+  glm::vec3 from = glm::vec3{nearPoint} / nearPoint.w;
+  glm::vec3 to = glm::vec3{farPoint} / farPoint.w;
+  return {from, glm::normalize(to - from)};
+}
+
+void ScenePanel::ViewportTransform::drawLine(ImDrawList* drawList,
+                                             const glm::vec3& a,
+                                             const glm::vec3& b, ImU32 color,
+                                             float thickness) const {
+  // Just in front of the camera. Points behind it project mirrored, so the
+  // part of the line there is cut off rather than drawn.
+  constexpr float MIN_W = 1e-4f;
+
+  glm::vec4 clipA = viewProjection * glm::vec4{a, 1.f};
+  glm::vec4 clipB = viewProjection * glm::vec4{b, 1.f};
+  if (clipA.w < MIN_W && clipB.w < MIN_W) {
+    return;
+  }
+  if (clipA.w < MIN_W) {
+    clipA = glm::mix(clipA, clipB, (MIN_W - clipA.w) / (clipB.w - clipA.w));
+  } else if (clipB.w < MIN_W) {
+    clipB = glm::mix(clipB, clipA, (MIN_W - clipB.w) / (clipA.w - clipB.w));
+  }
+  drawList->AddLine(clipToScreen(clipA), clipToScreen(clipB), color, thickness);
+}
+
+void ScenePanel::onUpdate(const sophia::FrameInfo& frameInfo) {
+  syncSceneView(context, sceneViews, view, isShown());
+
+  drawToolbar();
+  ImGui::Separator();
+
+  const ImVec2 origin = ImGui::GetCursorScreenPos();
+  const ImVec2 size = ImGui::GetContentRegionAvail();
+  if (size.x < 1.0f || size.y < 1.0f) {
+    return;
+  }
+
+  if (!context.hasScene()) {
+    ImGui::TextDisabled("No scene open");
+    return;
+  }
+
+  ui.image(target);
+
+  // Rolls over ImGuizmo's "mouse is over a handle" state, so IsOver() below
+  // reports last frame's.
+  ImGuizmo::BeginFrame();
+  // A handle can't be grabbed while any ImGui item is hovered, so while the
+  // mouse is over one, leave out the viewport button, and keep the window
+  // still so dragging the handle doesn't drag it. Unless a camera drag is
+  // already under way: dropping the button would end it.
+  bool overGizmo =
+      (ImGuizmo::IsOver() || ImGuizmo::IsUsing()) && !viewportActive;
+  getConfig().windowFlags =
+      overGizmo ? WINDOW_FLAGS | ImGuiWindowFlags_NoMove : WINDOW_FLAGS;
+
+  // The image doesn't take mouse input, so without this, dragging in it
+  // would drag the window instead.
+  ImGui::SetCursorScreenPos(origin);
+  if (overGizmo) {
+    ImGui::Dummy(size);
+  } else {
+    ImGui::InvisibleButton("##viewport", size,
+                           ImGuiButtonFlags_MouseButtonLeft |
+                               ImGuiButtonFlags_MouseButtonRight |
+                               ImGuiButtonFlags_MouseButtonMiddle);
+  }
+  viewportActive = !overGizmo && ImGui::IsItemActive();
+
+  handleCameraInput(frameInfo, size);
+  handleGizmoHotkeys();
+
+  // Drive the view's camera from the editor camera. The scene view renders
+  // after the panels update, so this frame already uses it.
+  camera.getComponent<sophia::TransformComponent>() =
+      editorCamera.getTransform();
+  camera.getComponent<sophia::CameraComponent>() = editorCamera.getCamera();
+
+  ImDrawList* drawList = ImGui::GetWindowDrawList();
+  drawList->PushClipRect(origin, ImVec2(origin.x + size.x, origin.y + size.y),
+                         true);
+
+  // Screen-space, so it only lines up with anything in 2D.
+  // TODO: a world-space grid on the XZ plane for 3D, once there's debug
+  // drawing in scene views.
+  if (showGrid && editorCamera.mode == EditorCamera::Mode::Scene2D) {
+    drawGrid(origin, size);
+  }
+
+  // Use the panel's size rather than the target's: the target is resized a
+  // frame late, and the mouse is over the panel.
+  float aspect = size.x / size.y;
+  glm::mat4 view = sophia::CameraComponent::getView(
+      camera.getComponent<sophia::TransformComponent>());
+  glm::mat4 viewProjection =
+      camera.getComponent<sophia::CameraComponent>().getProjection(aspect) *
+      view;
+  ViewportTransform viewport{origin, size, viewProjection,
+                             glm::inverse(viewProjection)};
+
+  handleSelectionInput(viewport);
+  drawSelection(viewport);
+
+  ImGuizmo::SetDrawlist();
+  ImGuizmo::SetRect(origin.x, origin.y, size.x, size.y);
+  drawGizmo(view, aspect);
+
+  drawList->PopClipRect();
+
+  ImGui::SetCursorScreenPos(ImVec2(origin.x + 8.0f, origin.y + 8.0f));
+  ImGui::TextDisabled("%.0f x %.0f", size.x, size.y);
+}
+
+void ScenePanel::drawToolbar() {
+  bool is2D = editorCamera.mode == EditorCamera::Mode::Scene2D;
+  if (ImGui::Checkbox("2D", &is2D)) {
+    editorCamera.mode =
+        is2D ? EditorCamera::Mode::Scene2D : EditorCamera::Mode::Scene3D;
+    dragging = false;
+  }
+  ImGui::SameLine();
+  ImGui::BeginDisabled(!is2D);
+  ImGui::Checkbox("Grid", &showGrid);
+  ImGui::EndDisabled();
+
+  ImGui::SameLine();
+  ImGui::TextDisabled("|");
+  ImGui::SameLine();
+  const struct {
+    const char* label;
+    GizmoOperation operation;
+  } operations[] = {{"Move (W)", GizmoOperation::Translate},
+                    {"Rotate (E)", GizmoOperation::Rotate},
+                    {"Scale (R)", GizmoOperation::Scale}};
+  for (const auto& entry : operations) {
+    if (ImGui::RadioButton(entry.label, gizmoOperation == entry.operation)) {
+      gizmoOperation = entry.operation;
+    }
+    ImGui::SameLine();
+  }
+  if (ImGui::Button(gizmoLocal ? "Local" : "World")) {
+    gizmoLocal = !gizmoLocal;
+  }
+}
+
+void ScenePanel::handleGizmoHotkeys() {
+  const ImGuiIO& io = ImGui::GetIO();
+  // W/E/Q fly the camera while the right button is held.
+  if (!ImGui::IsWindowFocused() || io.WantTextInput ||
+      ImGui::IsMouseDown(ImGuiMouseButton_Right)) {
+    return;
+  }
+  if (ImGui::IsKeyPressed(ImGuiKey_W, false)) {
+    gizmoOperation = GizmoOperation::Translate;
+  } else if (ImGui::IsKeyPressed(ImGuiKey_E, false)) {
+    gizmoOperation = GizmoOperation::Rotate;
+  } else if (ImGui::IsKeyPressed(ImGuiKey_R, false)) {
+    gizmoOperation = GizmoOperation::Scale;
+  }
+}
+
+void ScenePanel::drawGizmo(const glm::mat4& view, float aspect) {
+  sophia::Entity selected = context.selected;
+  if (!selected) {
+    return;
+  }
+
+  bool is2D = editorCamera.mode == EditorCamera::Mode::Scene2D;
+
+  // In 2D, only the axes that keep things in the XY plane.
+  ImGuizmo::OPERATION operation{};
+  float snapStep = 0.f;
+  switch (gizmoOperation) {
+    case GizmoOperation::Translate:
+      operation = is2D ? ImGuizmo::TRANSLATE_X | ImGuizmo::TRANSLATE_Y
+                       : ImGuizmo::TRANSLATE;
+      snapStep = TRANSLATE_SNAP;
+      break;
+    case GizmoOperation::Rotate:
+      operation = is2D ? ImGuizmo::ROTATE_Z : ImGuizmo::ROTATE;
+      snapStep = ROTATE_SNAP_DEGREES;
+      break;
+    case GizmoOperation::Scale:
+      operation =
+          is2D ? ImGuizmo::SCALE_X | ImGuizmo::SCALE_Y : ImGuizmo::SCALE;
+      snapStep = SCALE_SNAP;
+      break;
+  }
+  std::array<float, 3> snap{snapStep, snapStep, snapStep};
+  bool snapping = ImGui::GetIO().KeyCtrl;
+
+  // ImGuizmo maps clip space to the screen the OpenGL way, with +y up, so it
+  // needs the projection without the Y flip CameraComponent adds for Vulkan.
+  glm::mat4 projection =
+      camera.getComponent<sophia::CameraComponent>().getProjection(aspect);
+  projection[1][1] *= -1.f;
+
+  auto& transform = selected.getComponent<sophia::TransformComponent>();
+  glm::mat4 model = transform.mat4();
+
+  ImGuizmo::SetOrthographic(is2D);
+  // Per entity, so a drag in progress doesn't carry over to a new selection.
+  ImGuizmo::PushID(static_cast<int>(static_cast<sophia::u32>(selected)));
+  bool changed = ImGuizmo::Manipulate(
+      glm::value_ptr(view), glm::value_ptr(projection), operation,
+      gizmoLocal ? ImGuizmo::LOCAL : ImGuizmo::WORLD, glm::value_ptr(model),
+      nullptr, snapping ? snap.data() : nullptr);
+  ImGuizmo::PopID();
+
+  if (changed) {
+    decompose(model, transform);
+  }
+}
+
+void ScenePanel::drawGrid(ImVec2 origin, ImVec2 size) {
+  constexpr float GRID_STEP = 40.0f;
+  const ImU32 gridColor = IM_COL32(255, 255, 255, 18);
+  const ImVec2 end(origin.x + size.x, origin.y + size.y);
+
+  ImDrawList* drawList = ImGui::GetWindowDrawList();
+  for (float x = GRID_STEP; x < size.x; x += GRID_STEP) {
+    drawList->AddLine(ImVec2(origin.x + x, origin.y),
+                      ImVec2(origin.x + x, end.y), gridColor);
+  }
+  for (float y = GRID_STEP; y < size.y; y += GRID_STEP) {
+    drawList->AddLine(ImVec2(origin.x, origin.y + y),
+                      ImVec2(end.x, origin.y + y), gridColor);
+  }
+}
+
+void ScenePanel::handleCameraInput(const sophia::FrameInfo& frameInfo,
+                                   ImVec2 size) {
+  const ImGuiIO& io = ImGui::GetIO();
+  bool is3D = editorCamera.mode == EditorCamera::Mode::Scene3D;
+  glm::vec2 mouseDelta{io.MouseDelta.x, io.MouseDelta.y};
+
+  // The button stays active while any of its mouse buttons is held, even
+  // once the mouse leaves the panel.
+  if (ImGui::IsItemActive()) {
+    bool rightDown = ImGui::IsMouseDown(ImGuiMouseButton_Right);
+    bool middleDown = ImGui::IsMouseDown(ImGuiMouseButton_Middle);
+
+    if (is3D && rightDown) {
+      editorCamera.orbit(mouseDelta);
+
+      glm::vec3 direction{0.f};
+      if (ImGui::IsKeyDown(ImGuiKey_D)) direction.x += 1.f;
+      if (ImGui::IsKeyDown(ImGuiKey_A)) direction.x -= 1.f;
+      if (ImGui::IsKeyDown(ImGuiKey_E)) direction.y += 1.f;
+      if (ImGui::IsKeyDown(ImGuiKey_Q)) direction.y -= 1.f;
+      if (ImGui::IsKeyDown(ImGuiKey_S)) direction.z += 1.f;
+      if (ImGui::IsKeyDown(ImGuiKey_W)) direction.z -= 1.f;
+      editorCamera.fly(direction, static_cast<float>(frameInfo.deltaTime));
+    } else if (middleDown || (!is3D && rightDown)) {
+      editorCamera.pan(mouseDelta, size.y);
+    }
+  }
+
+  if (ImGui::IsItemHovered() && io.MouseWheel != 0.f) {
+    editorCamera.zoom(io.MouseWheel);
+  }
+
+  if (ImGui::IsWindowFocused() && !io.WantTextInput &&
+      ImGui::IsKeyPressed(ImGuiKey_F, false)) {
+    frameSelection();
+  }
+}
+
+void ScenePanel::handleSelectionInput(const ViewportTransform& viewport) {
+  const ImGuiIO& io = ImGui::GetIO();
+
+  if (ImGui::IsItemClicked(ImGuiMouseButton_Left)) {
+    context.selected = pick(viewport.screenToRay(io.MousePos));
+    // Dragging the selection around is 2D only; in 3D, use the gizmo.
+    dragging =
+        context.selected && editorCamera.mode == EditorCamera::Mode::Scene2D;
+  }
+
+  if (!ImGui::IsItemActive() || !ImGui::IsMouseDown(ImGuiMouseButton_Left)) {
+    dragging = false;
+    return;
+  }
+
+  if (dragging && (io.MouseDelta.x != 0.f || io.MouseDelta.y != 0.f)) {
+    ImVec2 previous(io.MousePos.x - io.MouseDelta.x,
+                    io.MousePos.y - io.MouseDelta.y);
+    glm::vec2 delta =
+        viewport.screenToWorld(io.MousePos) - viewport.screenToWorld(previous);
+
+    auto& transform =
+        context.selected.getComponent<sophia::TransformComponent>();
+    transform.position.x += delta.x;
+    transform.position.y += delta.y;
+  }
+}
+
+void ScenePanel::drawSelection(const ViewportTransform& viewport) {
+  sophia::Entity selected = context.selected;
+  if (!selected) {
+    return;
+  }
+
+  ImDrawList* drawList = ImGui::GetWindowDrawList();
+  const auto& transform = selected.getComponent<sophia::TransformComponent>();
+
+  if (selected.hasComponent<sophia::SpriteComponent>()) {
+    glm::mat4 model =
+        selected.getComponent<sophia::SpriteComponent>().getModel(transform);
+    for (size_t i = 0; i < UNIT_QUAD.size(); i++) {
+      const glm::vec2& from = UNIT_QUAD[i];
+      const glm::vec2& to = UNIT_QUAD[(i + 1) % UNIT_QUAD.size()];
+      viewport.drawLine(drawList, glm::vec3{model * glm::vec4{from, 0.f, 1.f}},
+                        glm::vec3{model * glm::vec4{to, 0.f, 1.f}},
+                        SELECTION_COLOR, 2.0f);
+    }
+  }
+
+  if (std::optional<sophia::AABB> bounds = getMeshBounds(selected)) {
+    glm::mat4 model = transform.mat4();
+    std::array<glm::vec3, 8> corners = bounds->getCorners();
+    for (glm::vec3& corner : corners) {
+      corner = glm::vec3{model * glm::vec4{corner, 1.f}};
+    }
+    // Corners whose indices differ in one bit share an edge.
+    for (int i = 0; i < 8; i++) {
+      for (int bit : {1, 2, 4}) {
+        if ((i & bit) == 0) {
+          viewport.drawLine(drawList, corners[i], corners[i | bit],
+                            SELECTION_COLOR, 2.0f);
+        }
+      }
+    }
+  }
+
+  // Mark the transform's position (the sprite's pivot), which is also all
+  // there is to show for entities without a sprite or mesh, such as the
+  // camera.
+  if (std::optional<ImVec2> center =
+          viewport.worldToScreen(transform.position)) {
+    drawList->AddCircle(*center, 4.0f, SELECTION_COLOR, 0, 2.0f);
+  }
+}
+
+void ScenePanel::frameSelection() {
+  sophia::Entity selected = context.selected;
+  if (!selected) {
+    return;
+  }
+
+  const auto& transform = selected.getComponent<sophia::TransformComponent>();
+
+  // The selection's corners in world space, from its mesh or sprite.
+  std::vector<glm::vec3> points;
+  if (std::optional<sophia::AABB> bounds = getMeshBounds(selected)) {
+    glm::mat4 model = transform.mat4();
+    for (const glm::vec3& corner : bounds->getCorners()) {
+      points.push_back(glm::vec3{model * glm::vec4{corner, 1.f}});
+    }
+  }
+  if (selected.hasComponent<sophia::SpriteComponent>()) {
+    glm::mat4 model =
+        selected.getComponent<sophia::SpriteComponent>().getModel(transform);
+    for (const glm::vec2& corner : UNIT_QUAD) {
+      points.push_back(glm::vec3{model * glm::vec4{corner, 0.f, 1.f}});
+    }
+  }
+
+  if (points.empty()) {
+    // Nothing with a size: frame a unit around its position.
+    editorCamera.frame(transform.position, 0.5f);
+    return;
+  }
+
+  glm::vec3 min = points.front();
+  glm::vec3 max = points.front();
+  for (const glm::vec3& point : points) {
+    min = glm::min(min, point);
+    max = glm::max(max, point);
+  }
+  editorCamera.frame((min + max) * 0.5f, glm::length(max - min) * 0.5f);
+}
+
+std::optional<sophia::AABB> ScenePanel::getMeshBounds(sophia::Entity entity) {
+  if (!entity.hasComponent<sophia::MeshComponent>()) {
+    return std::nullopt;
+  }
+  sophia::MeshHandle mesh = entity.getComponent<sophia::MeshComponent>().handle;
+  if (!resources.isAlive(mesh)) {
+    return std::nullopt;
+  }
+  return resources.getBounds(mesh);
+}
+
+sophia::Entity ScenePanel::pick(const Ray& ray) {
+  sophia::Scene& scene = context.getScene();
+
+  // Meshes are opaque and depth tested, so the nearest one hides anything
+  // behind it.
+  sophia::Entity nearestMesh;
+  float meshDistance = std::numeric_limits<float>::infinity();
+  scene.forEachEntity([&](sophia::Entity entity) {
+    std::optional<sophia::AABB> bounds = getMeshBounds(entity);
+    if (!bounds) {
+      return;
+    }
+    glm::mat4 model = entity.getComponent<sophia::TransformComponent>().mat4();
+    std::optional<float> distance =
+        intersectBox(ray.origin, ray.direction, model, *bounds);
+    if (distance && *distance < meshDistance) {
+      nearestMesh = entity;
+      meshDistance = *distance;
+    }
+  });
+
+  // Sprites in front of that mesh draw over it, in the renderer's order:
+  // higher sortOrder on top, then nearer.
+  sophia::Entity topSprite;
+  std::optional<std::tuple<sophia::s32, float>> topOrder;
+  scene.forEachEntity([&](sophia::Entity entity) {
+    if (!entity.hasComponent<sophia::SpriteComponent>()) {
+      return;
+    }
+    const auto& sprite = entity.getComponent<sophia::SpriteComponent>();
+    glm::mat4 model =
+        sprite.getModel(entity.getComponent<sophia::TransformComponent>());
+    std::optional<float> distance =
+        intersectQuad(ray.origin, ray.direction, model);
+    if (!distance || *distance > meshDistance) {
+      return;
+    }
+
+    // Negated distance, so nearer compares greater.
+    std::tuple order{sprite.sortOrder, -*distance};
+    if (!topOrder || order > *topOrder) {
+      topSprite = entity;
+      topOrder = order;
+    }
+  });
+
+  return topSprite ? topSprite : nearestMesh;
+}

editor/panels/scene_panel.hpp

@@ -0,0 +1,125 @@
+#pragma once
+
+#include <optional>
+#include <sophia/aabb.hpp>
+#include <sophia/entity.hpp>
+#include <sophia/frame_info.hpp>
+#include <sophia/handles.hpp>
+#include <sophia/math.hpp>
+#include <sophia/resource_registry_ref.hpp>
+#include <sophia/scene_view_registry.hpp>
+#include <sophia/ui/panel.hpp>
+#include <sophia/ui/ui.hpp>
+
+#include "../editor_camera.hpp"
+#include "../editor_context.hpp"
+
+/**
+ * Shows the active scene through the editor's own camera.
+ *
+ * 3D: right-drag orbits, middle-drag pans, the wheel zooms, right-drag with
+ * WASD/QE flies. 2D: right- or middle-drag pans, the wheel zooms. F frames
+ * the selection in both.
+ *
+ * The selection gets a transform gizmo: W moves, E rotates, R scales, and
+ * holding Ctrl snaps. Clicking selects the mesh or sprite under the mouse;
+ * in 2D, dragging it also moves it.
+ */
+class ScenePanel : public sophia::Panel {
+ public:
+  // Renders into `target` through `view`, a SceneView this panel keeps
+  // pointed at the active scene. `camera` is the entity the view looks
+  // through; it belongs to a scene of the editor's own, and this panel
+  // drives it from its EditorCamera.
+  ScenePanel(sophia::UI& ui, sophia::ResourceRegistryRef resources,
+             EditorContext& context, sophia::SceneViewRegistry& sceneViews,
+             sophia::SceneViewHandle view, sophia::RenderTargetHandle target,
+             sophia::Entity camera)
+      : Panel{{.name = "Scene", .windowFlags = WINDOW_FLAGS}},
+        ui{ui},
+        resources{resources},
+        context{context},
+        sceneViews{sceneViews},
+        view{view},
+        target{target},
+        camera{camera} {}
+
+  void onUpdate(const sophia::FrameInfo& frameInfo) override;
+
+ private:
+  static constexpr ImGuiWindowFlags WINDOW_FLAGS =
+      ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse;
+
+  enum class GizmoOperation { Translate, Rotate, Scale };
+
+  // A half-line in world space. `direction` is normalized, so distances
+  // along it are in world units.
+  struct Ray {
+    glm::vec3 origin;
+    glm::vec3 direction;
+  };
+
+  // Where the scene image is on screen this frame, and the camera looking
+  // through it.
+  struct ViewportTransform {
+    ImVec2 origin;
+    ImVec2 size;
+    glm::mat4 viewProjection;
+    glm::mat4 inverseViewProjection;
+
+    // Null for points behind the camera.
+    std::optional<ImVec2> worldToScreen(const glm::vec3& world) const;
+    // Where `screen` is on the camera's near plane. Only the x and y, which
+    // is all that's needed in 2D.
+    glm::vec2 screenToWorld(const ImVec2& screen) const;
+    // From the near plane through `screen`, into the scene.
+    Ray screenToRay(const ImVec2& screen) const;
+
+    // Draws a world-space line, cut off where it passes behind the camera.
+    void drawLine(ImDrawList* drawList, const glm::vec3& a, const glm::vec3& b,
+                  ImU32 color, float thickness) const;
+
+   private:
+    ImVec2 clipToScreen(const glm::vec4& clip) const;
+  };
+
+  void drawToolbar();
+  void drawGrid(ImVec2 origin, ImVec2 size);
+  void handleCameraInput(const sophia::FrameInfo& frameInfo, ImVec2 size);
+  void handleSelectionInput(const ViewportTransform& viewport);
+  void handleGizmoHotkeys();
+  // Draws the transform gizmo on the selection, and applies any change made
+  // with it. `view` is the editor camera's, and `aspect` the viewport's
+  // width over its height.
+  void drawGizmo(const glm::mat4& view, float aspect);
+  void drawSelection(const ViewportTransform& viewport);
+  void frameSelection();
+
+  // The bounds of the entity's mesh in the mesh's own space, if it has one.
+  std::optional<sophia::AABB> getMeshBounds(sophia::Entity entity);
+
+  // The entity drawn in front along `ray`, or a null Entity. Only meshes and
+  // sprites can be hit.
+  sophia::Entity pick(const Ray& ray);
+
+  sophia::UI& ui;
+  sophia::ResourceRegistryRef resources;
+  EditorContext& context;
+  sophia::SceneViewRegistry& sceneViews;
+  sophia::SceneViewHandle view;
+  sophia::RenderTargetHandle target;
+  sophia::Entity camera;
+
+  EditorCamera editorCamera;
+
+  GizmoOperation gizmoOperation = GizmoOperation::Translate;
+  // Whether the gizmo works along the entity's own axes or the world's.
+  bool gizmoLocal = true;
+  // Whether the viewport button was active last frame, i.e. a camera drag or
+  // click is under way, which the gizmo mustn't interrupt.
+  bool viewportActive = false;
+
+  bool showGrid = true;
+  // Set while a drag that started on the selected entity is moving it.
+  bool dragging = false;
+};

editor/panels/viewport_panel.cpp

@@ -1,202 +0,0 @@
-#include "viewport_panel.hpp"
-
-#include <imgui.h>
-
-#include <array>
-#include <optional>
-#include <sophia/components.hpp>
-#include <tuple>
-
-namespace {
-
-// Corners of the unit quad a SpriteComponent's model matrix maps to world.
-constexpr std::array<glm::vec2, 4> UNIT_QUAD{
-    glm::vec2{0.f, 0.f}, glm::vec2{1.f, 0.f}, glm::vec2{1.f, 1.f},
-    glm::vec2{0.f, 1.f}};
-
-const ImU32 SELECTION_COLOR = IM_COL32(255, 170, 40, 255);
-
-}  // namespace
-
-ImVec2 ViewportPanel::ViewportTransform::worldToScreen(
-    const glm::vec3& world) const {
-  glm::vec4 clip = viewProjection * glm::vec4{world, 1.f};
-  glm::vec2 ndc = glm::vec2{clip} / clip.w;
-  // Vulkan NDC has +y pointing down, same as the screen.
-  return {origin.x + (ndc.x * 0.5f + 0.5f) * size.x,
-          origin.y + (ndc.y * 0.5f + 0.5f) * size.y};
-}
-
-glm::vec2 ViewportPanel::ViewportTransform::screenToWorld(
-    const ImVec2& screen) const {
-  glm::vec2 ndc{(screen.x - origin.x) / size.x * 2.f - 1.f,
-                (screen.y - origin.y) / size.y * 2.f - 1.f};
-  glm::vec4 world = inverseViewProjection * glm::vec4{ndc, 0.f, 1.f};
-  return glm::vec2{world} / world.w;
-}
-
-void ViewportPanel::onUpdate(const sophia::FrameInfo&) {
-  drawToolbar();
-  ImGui::Separator();
-
-  const ImVec2 origin = ImGui::GetCursorScreenPos();
-  const ImVec2 size = ImGui::GetContentRegionAvail();
-  if (size.x < 1.0f || size.y < 1.0f) {
-    return;
-  }
-
-  ui.image(target);
-
-  // The image doesn't take mouse input, so without this, dragging in it
-  // would drag the window instead.
-  ImGui::SetCursorScreenPos(origin);
-  ImGui::InvisibleButton("##viewport", size);
-
-  ImDrawList* drawList = ImGui::GetWindowDrawList();
-  drawList->PushClipRect(origin, ImVec2(origin.x + size.x, origin.y + size.y),
-                         true);
-
-  if (showGrid) {
-    drawGrid(origin, size);
-  }
-
-  sophia::Entity camera = scene.getActiveCamera();
-  if (camera && camera.hasComponent<sophia::CameraComponent>()) {
-    // Use the panel's size rather than the target's: the target is resized
-    // a frame late, and the mouse is over the panel.
-    float aspect = size.x / size.y;
-    glm::mat4 viewProjection =
-        camera.getComponent<sophia::CameraComponent>().getViewProjection(
-            camera.getComponent<sophia::TransformComponent>(), aspect);
-
-    ViewportTransform viewport{origin, size, viewProjection,
-                               glm::inverse(viewProjection)};
-    handleInput(viewport);
-    drawSelection(viewport);
-  }
-
-  drawList->PopClipRect();
-
-  ImGui::SetCursorScreenPos(ImVec2(origin.x + 8.0f, origin.y + 8.0f));
-  ImGui::TextDisabled("%.0f x %.0f", size.x, size.y);
-}
-
-void ViewportPanel::drawToolbar() {
-  const struct {
-    const char* label;
-    GizmoMode mode;
-  } modes[] = {{"Move", GizmoMode::Move},
-               {"Rotate", GizmoMode::Rotate},
-               {"Scale", GizmoMode::Scale}};
-
-  for (const auto& entry : modes) {
-    if (ImGui::RadioButton(entry.label, gizmoMode == entry.mode)) {
-      gizmoMode = entry.mode;
-    }
-    ImGui::SameLine();
-  }
-  ImGui::Checkbox("Grid", &showGrid);
-}
-
-void ViewportPanel::drawGrid(ImVec2 origin, ImVec2 size) {
-  constexpr float GRID_STEP = 40.0f;
-  const ImU32 gridColor = IM_COL32(255, 255, 255, 18);
-  const ImVec2 end(origin.x + size.x, origin.y + size.y);
-
-  ImDrawList* drawList = ImGui::GetWindowDrawList();
-  for (float x = GRID_STEP; x < size.x; x += GRID_STEP) {
-    drawList->AddLine(ImVec2(origin.x + x, origin.y),
-                      ImVec2(origin.x + x, end.y), gridColor);
-  }
-  for (float y = GRID_STEP; y < size.y; y += GRID_STEP) {
-    drawList->AddLine(ImVec2(origin.x, origin.y + y),
-                      ImVec2(end.x, origin.y + y), gridColor);
-  }
-}
-
-void ViewportPanel::handleInput(const ViewportTransform& viewport) {
-  const ImGuiIO& io = ImGui::GetIO();
-
-  if (ImGui::IsItemActivated()) {
-    selected = pick(viewport.screenToWorld(io.MousePos));
-    dragging = selected && gizmoMode == GizmoMode::Move;
-  }
-
-  if (!ImGui::IsItemActive()) {
-    dragging = false;
-    return;
-  }
-
-  if (dragging && (io.MouseDelta.x != 0.f || io.MouseDelta.y != 0.f)) {
-    ImVec2 previous(io.MousePos.x - io.MouseDelta.x,
-                    io.MousePos.y - io.MouseDelta.y);
-    glm::vec2 delta =
-        viewport.screenToWorld(io.MousePos) - viewport.screenToWorld(previous);
-
-    auto& transform = selected.getComponent<sophia::TransformComponent>();
-    transform.position.x += delta.x;
-    transform.position.y += delta.y;
-  }
-}
-
-void ViewportPanel::drawSelection(const ViewportTransform& viewport) {
-  if (!selected) {
-    return;
-  }
-
-  ImDrawList* drawList = ImGui::GetWindowDrawList();
-  const auto& transform = selected.getComponent<sophia::TransformComponent>();
-
-  if (selected.hasComponent<sophia::SpriteComponent>()) {
-    glm::mat4 model =
-        selected.getComponent<sophia::SpriteComponent>().getModel(transform);
-
-    std::array<ImVec2, 4> corners;
-    for (size_t i = 0; i < UNIT_QUAD.size(); i++) {
-      corners[i] = viewport.worldToScreen(
-          glm::vec3{model * glm::vec4{UNIT_QUAD[i], 0.f, 1.f}});
-    }
-    drawList->AddQuad(corners[0], corners[1], corners[2], corners[3],
-                      SELECTION_COLOR, 2.0f);
-  }
-
-  // Mark the transform's position (the sprite's pivot), which is also all
-  // there is to show for entities without a sprite, such as the camera.
-  ImVec2 center = viewport.worldToScreen(transform.position);
-  drawList->AddCircle(center, 4.0f, SELECTION_COLOR, 0, 2.0f);
-}
-
-sophia::Entity ViewportPanel::pick(glm::vec2 world) {
-  sophia::Entity best;
-  std::optional<std::tuple<sophia::s32, float>> bestOrder;
-
-  scene.forEachEntity([&](sophia::Entity entity) {
-    if (!entity.hasComponent<sophia::SpriteComponent>()) {
-      return;
-    }
-
-    const auto& transform = entity.getComponent<sophia::TransformComponent>();
-    const auto& sprite = entity.getComponent<sophia::SpriteComponent>();
-
-    glm::mat4 model = sprite.getModel(transform);
-    // Zero size or scale; nothing to hit.
-    if (glm::determinant(model) == 0.f) {
-      return;
-    }
-
-    glm::vec4 local =
-        glm::inverse(model) * glm::vec4{world, transform.position.z, 1.f};
-    if (local.x < 0.f || local.x > 1.f || local.y < 0.f || local.y > 1.f) {
-      return;
-    }
-
-    // Same ordering the renderer draws in, so this is the one on top.
-    std::tuple order{sprite.sortOrder, transform.position.z};
-    if (!bestOrder || order >= *bestOrder) {
-      best = entity;
-      bestOrder = order;
-    }
-  });
-
-  return best;
-}

editor/panels/viewport_panel.hpp

@@ -1,64 +0,0 @@
-#pragma once
-
-#include <sophia/entity.hpp>
-#include <sophia/frame_info.hpp>
-#include <sophia/handles.hpp>
-#include <sophia/math.hpp>
-#include <sophia/scene.hpp>
-#include <sophia/ui/panel.hpp>
-#include <sophia/ui/ui.hpp>
-
-/**
- * Shows the scene through its active camera. Click a sprite to select it,
- * drag it to move it (in Move mode).
- *
- * Picking and moving are 2D: they assume an orthographic camera rotated only
- * around Z, and work in the z = 0 plane.
- */
-class ViewportPanel : public sophia::Panel {
- public:
-  ViewportPanel(sophia::UI& ui, sophia::RenderTargetHandle target,
-                sophia::Scene& scene, sophia::Entity& selected)
-      : Panel{{.name = "Viewport",
-               .windowFlags = ImGuiWindowFlags_NoScrollbar |
-                              ImGuiWindowFlags_NoScrollWithMouse}},
-        ui{ui},
-        target{target},
-        scene{scene},
-        selected{selected} {}
-
-  void onUpdate(const sophia::FrameInfo& frameInfo) override;
-
- private:
-  // Where the scene image is on screen this frame, and the camera looking
-  // through it.
-  struct ViewportTransform {
-    ImVec2 origin;
-    ImVec2 size;
-    glm::mat4 viewProjection;
-    glm::mat4 inverseViewProjection;
-
-    ImVec2 worldToScreen(const glm::vec3& world) const;
-    glm::vec2 screenToWorld(const ImVec2& screen) const;
-  };
-
-  void drawToolbar();
-  void drawGrid(ImVec2 origin, ImVec2 size);
-  void handleInput(const ViewportTransform& viewport);
-  void drawSelection(const ViewportTransform& viewport);
-
-  // The top-most sprite under `world`, or a null Entity.
-  sophia::Entity pick(glm::vec2 world);
-
-  sophia::UI& ui;
-  sophia::RenderTargetHandle target;
-  sophia::Scene& scene;
-  sophia::Entity& selected;
-
-  enum class GizmoMode { Move, Rotate, Scale };
-
-  GizmoMode gizmoMode = GizmoMode::Move;
-  bool showGrid = true;
-  // Set while a drag that started on the selected entity is moving it.
-  bool dragging = false;
-};

editor/utilities/logger.hpp

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <sophia/util/logger.hpp>
+
+template <typename... Args>
+void log(Args... args) {
+  sophia::log::print("\033[1;38;2;170;90;255m[editor]\033[0m", args...);
+}

engine/include/sophia/aabb.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <array>
+#include <sophia/math.hpp>
+
+namespace sophia {
+
+/** @brief Axis-Aligned Bounding Box
+ *
+ * An axis-aligned box, from its smallest corner to its largest.
+ */
+struct AABB {
+  vec3 min{0.f, 0.f, 0.f};
+  vec3 max{0.f, 0.f, 0.f};
+
+  vec3 getCenter() const { return (min + max) * 0.5f; }
+  vec3 getSize() const { return max - min; }
+
+  // The 8 corners. Bit 0 of the index picks x from max, bit 1 y, bit 2 z.
+  std::array<vec3, 8> getCorners() const {
+    std::array<vec3, 8> corners;
+    for (int i = 0; i < 8; i++) {
+      corners[i] = {(i & 1) ? max.x : min.x, (i & 2) ? max.y : min.y,
+                    (i & 4) ? max.z : min.z};
+    }
+    return corners;
+  }
+};
+
+}  // namespace sophia

engine/include/sophia/application.hpp

@@ -3,7 +3,6 @@
 #include <cstdlib>
 #include <iostream>
 #include <memory>
-#include <sophia/camera_2d.hpp>
 #include <sophia/canvas.hpp>
 #include <sophia/console/console_command_registry.hpp>
 #include <sophia/frame_info.hpp>
@@ -53,7 +52,6 @@ class Application {
   DebugUI& debugUI() { return this->_debugUI; }
 
   Canvas canvas;
-  Camera2D camera;
   std::vector<std::string> args;
 
   ConsoleCommandRegistry consoleCommandRegistry;

engine/include/sophia/camera_2d.hpp

@@ -1,28 +0,0 @@
-#pragma once
-
-#include <glm/gtc/matrix_transform.hpp>
-#include <sophia/math.hpp>
-
-namespace sophia {
-
-class Camera2D {
- public:
-  glm::vec2 position{0.f, 0.f};
-
-  void setProjection(float left, float right, float bottom, float top) {
-    projection = glm::ortho(left, right, bottom, top);
-  }
-
-  const glm::mat4& getProjection() const { return projection; }
-
-  glm::mat4 getView() const {
-    return glm::translate(glm::mat4(1.f), glm::vec3(-position, 0.f));
-  }
-
-  glm::mat4 getViewProjection() const { return projection * getView(); }
-
- private:
-  glm::mat4 projection{1.f};
-};
-
-}  // namespace sophia

engine/include/sophia/components.hpp

@@ -43,8 +43,15 @@ struct TransformComponent {
   }
 };
 
+/**
+ * Draws a mesh, placed by the entity's TransformComponent. Opaque and unlit
+ * for now.
+ */
 struct MeshComponent {
   MeshHandle handle;
+  // Multiplied with the mesh's vertex colors. Alpha is ignored. Stands in for
+  // a material until there are materials.
+  glm::vec4 color{1.f, 1.f, 1.f, 1.f};
 };
 
 /**
@@ -58,13 +65,17 @@ struct SpriteComponent {
 
   // Size in world units, before the transform's scale.
   glm::vec2 size{1.f, 1.f};
-  // Point on the sprite, from (0, 0) to (1, 1) across its size, that sits at
+  // Point on the sprite, from (0, 0) at its bottom-left to (1, 1) at its
-  // the transform's position and that it rotates around.
+  // top-right, that sits at the transform's position and that it rotates
+  // around.
   glm::vec2 pivot{0.5f, 0.5f};
-  // Region of the texture to draw, as normalized (u0, v0, u1, v1).
+  // Region of the texture to draw, as normalized (u0, v0, u1, v1) with
+  // (0, 0) at the texture's top-left.
   glm::vec4 uvRect{0.f, 0.f, 1.f, 1.f};
 
-  // Higher draws on top. Ties are broken by the transform's position.z.
+  // Higher draws on top, whatever the depth. Sprites with the same sortOrder
+  // draw back to front from the camera; the transform's position.z is depth
+  // like any other axis, not a layer.
   s32 sortOrder = 0;
 
   // Maps the unit quad (0, 0)-(1, 1) to world space: to the sprite's
@@ -79,8 +90,8 @@ struct SpriteComponent {
 struct CameraComponent {
   struct Orthographic {
     float height = 10.f;
-    float nearPlane = -1.f;
+    float nearPlane = -1000.f;
-    float farPlane = 1.f;
+    float farPlane = 1000.f;
   };
 
   struct Perspective {
@@ -95,25 +106,37 @@ struct CameraComponent {
   Orthographic ortho;
   Perspective perspective;
 
+  // View -> clip space. World +Y is up on screen: Vulkan's clip space has +Y
+  // pointing down, so the projection flips it.
   glm::mat4 getProjection(float aspect) const {
+    glm::mat4 result;
     if (projection == Projection::Perspective) {
-      return glm::perspective(perspective.fov, aspect, perspective.nearPlane,
+      result = glm::perspective(perspective.fov, aspect, perspective.nearPlane,
-                              perspective.farPlane);
+                                perspective.farPlane);
+    } else {
+      float halfHeight = ortho.height / 2.f;
+      float halfWidth = halfHeight * aspect;
+      result = glm::ortho(-halfWidth, halfWidth, -halfHeight, halfHeight,
+                          ortho.nearPlane, ortho.farPlane);
     }
 
-    float halfHeight = ortho.height / 2.f;
+    result[1][1] *= -1.f;
-    float halfWidth = halfHeight * aspect;
+    return result;
-    return glm::ortho(-halfWidth, halfWidth, -halfHeight, halfHeight,
-                      ortho.nearPlane, ortho.farPlane);
   }
 
-  // World -> clip space for this camera placed by `transform`. The view
+  // World -> view space for this camera placed by `transform`. Ignores the
-  // ignores the transform's scale; zoom is the projection's job.
+  // transform's scale; zoom is the projection's job. The camera looks down
-  glm::mat4 getViewProjection(const TransformComponent& transform,
+  // view-space -Z.
-                              float aspect) const {
+  static glm::mat4 getView(const TransformComponent& transform) {
     glm::mat4 world = glm::translate(glm::mat4{1.f}, transform.position) *
                       glm::mat4_cast(transform.rotation);
-    return getProjection(aspect) * glm::inverse(world);
+    return glm::inverse(world);
+  }
+
+  // World -> clip space for this camera placed by `transform`.
+  glm::mat4 getViewProjection(const TransformComponent& transform,
+                              float aspect) const {
+    return getProjection(aspect) * getView(transform);
   }
 };
 

engine/include/sophia/frame_info.hpp

@@ -1,6 +1,5 @@
 #pragma once
 
-#include <sophia/camera_2d.hpp>
 #include <sophia/math.hpp>
 #include <sophia/types.hpp>
 
@@ -11,7 +10,6 @@ struct FrameInfo {
   double elapsedTime;
   double deltaTime;
   glm::vec2 currentFramebufferExtent;
-  const Camera2D& camera;
 };
 
 }  // namespace sophia

engine/include/sophia/mesh_data.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <sophia/math.hpp>
+#include <sophia/types.hpp>
+#include <vector>
+
+namespace sophia {
+
+// Layout must match the per-vertex inputs in mesh.vert.
+struct MeshVertex {
+  vec3 position{0.f, 0.f, 0.f};
+  vec3 normal{0.f, 0.f, 1.f};
+  // Texture coordinates, with (0, 0) at the texture's top-left.
+  vec2 uv{0.f, 0.f};
+  vec4 color{1.f, 1.f, 1.f, 1.f};
+};
+
+/**
+ * Geometry on the CPU, uploaded with `resources().create<Mesh>(data)`.
+ * Triangles wind counter-clockwise when seen from the front; back faces are
+ * culled. See primitives.hpp for ready-made shapes.
+ */
+struct MeshData {
+  std::vector<MeshVertex> vertices;
+  // Empty draws the vertices in order, three per triangle.
+  std::vector<u32> indices;
+};
+
+}  // namespace sophia

engine/include/sophia/primitives.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <sophia/math.hpp>
+#include <sophia/mesh_data.hpp>
+
+/**
+ * Ready-made shapes, centered on the origin. They return MeshData rather than
+ * a mesh so they can be adjusted before uploading:
+ *
+ *   MeshHandle cube = resources().create<Mesh>(primitives::cube());
+ */
+namespace sophia::primitives {
+
+// An axis-aligned cube `size` across. Each face has its own four vertices so
+// it gets its own normal and UVs.
+MeshData cube(float size = 1.f, vec4 color = vec4{1.f});
+
+}  // namespace sophia::primitives

engine/include/sophia/resource_registry_ref.hpp

@@ -1,8 +1,9 @@
 #pragma once
 
-#include <sophia/canvas.hpp>
+#include <sophia/aabb.hpp>
 #include <sophia/handles.hpp>
 #include <sophia/math.hpp>
+#include <sophia/mesh_data.hpp>
 #include <sophia/types.hpp>
 #include <string>
 #include <type_traits>
@@ -28,6 +29,10 @@ class ResourceRegistryRef {
   glm::vec2 getExtent(RenderTargetHandle handle) const;
   glm::vec2 getExtent(TextureHandle handle) const;
 
+  // In the mesh's own space.
+  AABB getBounds(MeshHandle handle) const;
+
+  bool isAlive(MeshHandle handle) const;
   bool isAlive(RenderTargetHandle handle) const;
   bool isAlive(TextureHandle handle) const;
 
@@ -40,9 +45,7 @@ class ResourceRegistryRef {
   explicit ResourceRegistryRef(ResourceRegistry& registry)
       : registry{&registry} {}
 
-  MeshHandle createResource(std::type_identity<Mesh>,
+  MeshHandle createResource(std::type_identity<Mesh>, const MeshData& data);
-                            std::vector<CanvasVertex> vertices,
-                            std::vector<u32> indices = {});
 
   RenderTargetHandle createResource(std::type_identity<RenderTarget>,
                                     u32 width = 1, u32 height = 1);

engine/include/sophia/scene.hpp

@@ -25,12 +25,20 @@ class Scene {
   Entity getActiveCamera();
   void setActiveCamera(Entity camera);
 
+  bool isVisible() const { return this->visible; }
+  void setVisible(bool visible) { this->visible = visible; }
+
+  bool isActive() const { return this->active; }
+  void setActive(bool active) { this->active = active; }
+
  private:
   friend class Entity;
   friend class SceneRenderer;  // !TEMP remove this
 
   entt::registry registry;
   entt::entity activeCamera = entt::null;
+  bool visible = true;
+  bool active = true;
 };
 
 }  // namespace sophia

engine/include/sophia/scene_view.hpp

@@ -19,8 +19,11 @@ struct SceneView {
   SceneHandle scene = INVALID_HANDLE;
   RenderTargetHandle target =
       INVALID_HANDLE;  // null implies render to swapchain
-  Entity camera;       // null implies use scene's active camera
+  // Null implies the scene's active camera. May belong to another scene,
+  // e.g. an editor camera that isn't part of the scene being shown.
+  Entity camera;
 
+  // TODO(#76): not used yet; every view renders to its whole target.
   vec4 viewport{0.0f, 0.0f, 1.0f, 1.0f};
 
   vec4 clearColor{0.f, 0.f, 0.f, 1.f};

engine/include/sophia/ui/panel.hpp

@@ -48,6 +48,7 @@ class Panel {
   bool isLocked() const { return config.locked; }
 
   bool isVisible() const { return this->visible; }
+  bool isShown() const { return this->visible && this->shown; }
   void setVisible(bool visible) { this->visible = visible; }
   void toggleVisible() { this->visible = !this->visible; }
 
@@ -55,6 +56,7 @@ class Panel {
   virtual void onUpdate(const FrameInfo& frameInfo) = 0;
 
   bool visible = true;
+  bool shown = false;
 
  private:
   Config config;

engine/include/sophia/util/logger.hpp

@@ -5,6 +5,7 @@
  * using namespace sophia;
  * log::fatal("fatal message")
  * log::info("Infomation message")
+ * log::print("no prefix, just the message")
  *
  * TODO Impl some form of log error handling
  */
@@ -122,4 +123,24 @@ void trace(Args... args) {
   log(LEVEL::TRACE, args...);
 }
 
+// Like the functions above, but with no "[LEVEL]" prefix: just the arguments,
+// separated by spaces, then a newline. With none, an empty line.
+inline void print() {
+#ifndef NDEBUG
+  std::cout << std::endl;
+#endif  // !NDEBUG
+}
+
+template <typename First, typename... Rest>
+void print(First first, Rest... rest) {
+#ifndef NDEBUG
+  std::cout << first;
+  ((std::cout << ' ' << rest), ...);
+  std::cout << std::endl;
+#else
+  (void)first;
+  (void)std::initializer_list<int>{((void)rest, 0)...};
+#endif  // !NDEBUG
+}
+
 }  // namespace sophia::log

engine/src/application.cpp

@@ -5,7 +5,9 @@
 #include <chrono>
 #include <cstddef>
 #include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
 #include <map>
+#include <optional>
 #include <set>
 #include <sophia/application.hpp>
 #include <sophia/util/logger.hpp>
@@ -92,8 +94,9 @@ class Application::Impl {
 
     imguiRenderer.setDefaultLayout(panelRegistry.getDefaultLayout());
 
-    // Views already warned about having no camera, so each warns once.
+    // Views already warned about, so each warns once.
     std::set<SceneViewHandle> viewsWithoutCamera;
+    std::set<SceneViewHandle> viewsOverwritingOthers;
 
     auto startTime = std::chrono::high_resolution_clock::now();
     auto currentTime = startTime;
@@ -117,17 +120,20 @@ class Application::Impl {
       vk::Extent2D extent = renderContext.getExtent();
       FrameInfo frameInfo{frameIndex, elapsedTime, deltaTime,
                           glm::vec2(static_cast<float>(extent.width),
-                                    static_cast<float>(extent.height)),
+                                    static_cast<float>(extent.height))};
-                          this->application.camera};
       {
         ZoneScopedN("Application::onUpdate");
         this->application.onUpdate(frameInfo);
       }
-      this->application.camera.setProjection(
+
-          -frameInfo.currentFramebufferExtent.x / 2.f,
+      // Canvas draws in window pixels, origin at the center.
-          frameInfo.currentFramebufferExtent.x / 2.f,
+      // TODO: replace with Debug/Gizmos drawn into scene views through their
-          -frameInfo.currentFramebufferExtent.y / 2.f,
+      // cameras.
-          frameInfo.currentFramebufferExtent.y / 2.f);
+      glm::mat4 canvasProjection =
+          glm::ortho(-frameInfo.currentFramebufferExtent.x / 2.f,
+                     frameInfo.currentFramebufferExtent.x / 2.f,
+                     -frameInfo.currentFramebufferExtent.y / 2.f,
+                     frameInfo.currentFramebufferExtent.y / 2.f);
 
       vk::CommandBuffer commandBuffer = renderContext.beginFrame();
       if (!commandBuffer) {
@@ -152,37 +158,79 @@ class Application::Impl {
                        this->drawCalls.end());
       this->drawCalls.clear();
 
-      RenderGraph graph;
+      RenderGraph graph{renderContext.getTracyContext()};
       ImageRef backbuffer =
           graph.importImage(renderContext.getCurrentImage(), Access::Present);
 
-      std::map<RenderTargetHandle, ImageRef> viewTargets;
+      struct ViewTarget {
+        ImageRef color;
+        ImageRef depth;
+      };
+      std::map<RenderTargetHandle, ViewTarget> viewTargets;
+      // Views without a target render straight into the backbuffer.
+      std::optional<ViewTarget> swapchainTarget;
       for (SceneViewHandle handle : sceneViewRegistry.GetRenderQueue()) {
         const SceneView& view = sceneViewRegistry.peek(handle);
+        bool toSwapchain = !view.target.isValid();
         if (!sceneRegistry.isAlive(view.scene) ||
-            !renderTargetPool.isAlive(view.target)) {
+            !sceneRegistry.get(view.scene).isVisible() ||
+            (!toSwapchain && !renderTargetPool.isAlive(view.target))) {
           continue;
         }
 
-        auto [it, inserted] = viewTargets.try_emplace(view.target);
+        ViewTarget target;
-        if (inserted) {
+        vk::Extent2D targetExtent;
-          it->second =
+        // Whether this is the first view this frame to render to its target.
-              graph.importImage(renderTargetPool.get(view.target).getImage(),
+        bool firstOnTarget = false;
-                                Access::SampledRead);
+        if (toSwapchain) {
+          firstOnTarget = !swapchainTarget;
+          if (!swapchainTarget) {
+            swapchainTarget = {
+                backbuffer,
+                graph.importImage(renderContext.getCurrentDepthImage(),
+                                  Access::DepthWrite)};
+          }
+          target = *swapchainTarget;
+          targetExtent = renderContext.getExtent();
+        } else {
+          RenderTarget& renderTarget = renderTargetPool.get(view.target);
+          auto [it, inserted] = viewTargets.try_emplace(view.target);
+          firstOnTarget = inserted;
+          if (inserted) {
+            it->second = {
+                graph.importImage(renderTarget.getImage(), Access::SampledRead),
+                graph.importImage(renderTarget.getDepthImage(),
+                                  Access::DepthWrite)};
+          }
+          target = it->second;
+          targetExtent = renderTarget.getExtent();
+        }
+
+        if (!firstOnTarget && hasFlag(view.clearFlags, ClearFlags::Color) &&
+            viewsOverwritingOthers.insert(handle).second) {
+          log::warning(
+              "scene view clears its target after another view already "
+              "rendered to it this frame, hiding that view (give it clearFlags "
+              "without Color, or render it first with a lower priority)");
         }
 
         const vec4& color = view.clearColor;
         graph.addPass(
-            "scene view",
+            "scene view " + std::to_string(handle.index),
             [&](RenderGraph::PassBuilder& pass) {
-              pass.writeColor(it->second,
+              pass.writeColor(target.color,
                               hasFlag(view.clearFlags, ClearFlags::Color)
                                   ? vk::AttachmentLoadOp::eClear
                                   : vk::AttachmentLoadOp::eLoad,
                               {color.r, color.g, color.b, color.a});
+              pass.writeDepth(target.depth,
+                              hasFlag(view.clearFlags, ClearFlags::Depth)
+                                  ? vk::AttachmentLoadOp::eClear
+                                  : vk::AttachmentLoadOp::eLoad);
             },
             [&sceneRenderer, &sceneRegistry, &sceneViewRegistry,
-             &viewsWithoutCamera, handle](vk::CommandBuffer commandBuffer) {
+             &viewsWithoutCamera, handle,
+             targetExtent](vk::CommandBuffer commandBuffer) {
               ZoneScopedN("scene view pass");
               const SceneView& view = sceneViewRegistry.peek(handle);
               Entity camera =
@@ -198,22 +246,26 @@ class Application::Impl {
                 }
                 return;
               }
-              sceneRenderer.render(commandBuffer, view, camera);
+              sceneRenderer.render(commandBuffer, view, camera, targetExtent);
             });
       }
 
       graph.addPass(
           "main",
           [&](RenderGraph::PassBuilder& pass) {
-            pass.writeColor(backbuffer, vk::AttachmentLoadOp::eClear,
+            // Keep what scene views drew into the backbuffer.
+            pass.writeColor(backbuffer,
+                            swapchainTarget ? vk::AttachmentLoadOp::eLoad
+                                            : vk::AttachmentLoadOp::eClear,
                             CLEAR_COLOR);
             for (const auto& [handle, target] : viewTargets) {
-              pass.sample(target);
+              pass.sample(target.color);
             }
           },
           [&](vk::CommandBuffer commandBuffer) {
             ZoneScopedN("main pass");
-            modelRenderSystem.render(commandBuffer, instances, frameInfo);
+            modelRenderSystem.render(commandBuffer, instances,
+                                     canvasProjection);
 
             imguiRenderer.endFrame(commandBuffer);
           });
@@ -239,14 +291,15 @@ class Application::Impl {
   }
 
   void pushMesh(std::vector<CanvasVertex> vertices, std::vector<u32> indices) {
-    Mesh::Builder builder{};
+    MeshData data;
-    builder.vertices.reserve(vertices.size());
+    data.vertices.reserve(vertices.size());
     for (const CanvasVertex& vertex : vertices) {
-      builder.vertices.push_back({vertex.position, vertex.color});
+      data.vertices.push_back(
+          {.position = {vertex.position, 0.f}, .color = {vertex.color, 1.f}});
     }
-    builder.indices = std::move(indices);
+    data.indices = std::move(indices);
 
-    this->meshes.push_back(std::make_unique<Mesh>(this->device, builder));
+    this->meshes.push_back(std::make_unique<Mesh>(this->device, data));
   }
 
   void clearMeshes() {

engine/src/renderer/mesh_render_system.cpp

@@ -0,0 +1,153 @@
+#include "renderer/mesh_render_system.hpp"
+
+#include <algorithm>
+#include <sophia/util/logger.hpp>
+#include <tracy/Tracy.hpp>
+
+#include "shaders/mesh.frag.spv.h"
+#include "shaders/mesh.vert.spv.h"
+
+namespace sophia {
+
+namespace {
+// Mesh::getAttributeDescriptions() takes locations below this.
+constexpr u32 FIRST_INSTANCE_LOCATION = 4;
+}  // namespace
+
+MeshRenderSystem::MeshRenderSystem(Device& device, vk::Format colorFormat,
+                                   vk::Format depthFormat,
+                                   ResourceRegistry& resources)
+    : device{device}, resources{resources} {
+  createPipelineLayout();
+  createPipeline(colorFormat, depthFormat);
+  createInstanceBuffers();
+}
+
+MeshRenderSystem::~MeshRenderSystem() {
+  log::trace("destroyed sophia::MeshRenderSystem");
+}
+
+void MeshRenderSystem::beginFrame(u32 frameIndex) {
+  this->frameIndex = frameIndex;
+  this->instanceCursor = 0;
+}
+
+void MeshRenderSystem::render(vk::CommandBuffer commandBuffer,
+                              const glm::mat4& viewProjection,
+                              std::span<const Instance> instances,
+                              std::span<const Batch> batches) {
+  ZoneScoped;
+  if (instances.empty()) {
+    return;
+  }
+
+  u32 available = MAX_INSTANCES_PER_FRAME - this->instanceCursor;
+  if (instances.size() > available) {
+    log::warning("MeshRenderSystem: frame instance buffer full, dropping",
+                 instances.size() - available, "meshes");
+  }
+
+  Buffer& buffer = *this->instanceBuffers[this->frameIndex];
+  u32 base = this->instanceCursor;
+  u32 count = std::min(static_cast<u32>(instances.size()), available);
+  buffer.writeToBuffer(const_cast<Instance*>(instances.data()),
+                       count * sizeof(Instance), base * sizeof(Instance));
+  this->instanceCursor += count;
+
+  this->graphicsPipeline->bind(commandBuffer);
+
+  PushConstantData push{viewProjection};
+  commandBuffer.pushConstants(this->pipelineLayout.get(),
+                              vk::ShaderStageFlagBits::eVertex, 0,
+                              sizeof(PushConstantData), &push);
+
+  // Binding 1 stays bound across batches; each mesh rebinds binding 0.
+  vk::Buffer instanceBuffer = buffer.getBuffer();
+  vk::DeviceSize offset = 0;
+  commandBuffer.bindVertexBuffers(1, 1, &instanceBuffer, &offset);
+
+  for (const Batch& batch : batches) {
+    if (batch.firstInstance >= count) {
+      break;
+    }
+    u32 batchCount = std::min(batch.instanceCount, count - batch.firstInstance);
+
+    const Mesh& mesh = this->resources.meshPool.get(batch.mesh);
+    mesh.bind(commandBuffer);
+    mesh.draw(commandBuffer, batchCount, base + batch.firstInstance);
+  }
+}
+
+void MeshRenderSystem::createPipelineLayout() {
+  vk::PushConstantRange pushConstantRange{};
+  pushConstantRange.stageFlags = vk::ShaderStageFlagBits::eVertex;
+  pushConstantRange.offset = 0;
+  pushConstantRange.size = sizeof(PushConstantData);
+
+  vk::PipelineLayoutCreateInfo pipelineLayoutInfo = {};
+  pipelineLayoutInfo.setLayoutCount = 0;
+  pipelineLayoutInfo.pushConstantRangeCount = 1;
+  pipelineLayoutInfo.pPushConstantRanges = &pushConstantRange;
+
+  try {
+    this->pipelineLayout =
+        this->device.get()->createPipelineLayoutUnique(pipelineLayoutInfo);
+    log::trace("created vk::PipelineLayout");
+  } catch (const vk::SystemError& err) {
+    log::fatal("failed to create vk::PipelineLayout");
+    throw std::runtime_error("failed to create vk::PipelineLayout");
+  }
+}
+
+void MeshRenderSystem::createPipeline(vk::Format colorFormat,
+                                      vk::Format depthFormat) {
+  auto vertexShader = Shader::Builder()
+                          .fromSPIRV(shaders::mesh_vert_spv)
+                          .setStage(ShaderStage::VERTEX)
+                          .build();
+  auto fragmentShader = Shader::Builder()
+                            .fromSPIRV(shaders::mesh_frag_spv)
+                            .setStage(ShaderStage::FRAGMENT)
+                            .build();
+
+  std::vector<vk::VertexInputBindingDescription> bindings =
+      Mesh::getBindingDescriptions();
+  bindings.push_back({1, sizeof(Instance), vk::VertexInputRate::eInstance});
+
+  std::vector<vk::VertexInputAttributeDescription> attributes =
+      Mesh::getAttributeDescriptions();
+  // A mat4 attribute takes four consecutive locations, one per column.
+  for (u32 column = 0; column < 4; column++) {
+    attributes.push_back({FIRST_INSTANCE_LOCATION + column, 1,
+                          vk::Format::eR32G32B32A32Sfloat,
+                          static_cast<u32>(offsetof(Instance, model) +
+                                           column * sizeof(glm::vec4))});
+  }
+  attributes.push_back({FIRST_INSTANCE_LOCATION + 4, 1,
+                        vk::Format::eR32G32B32A32Sfloat,
+                        static_cast<u32>(offsetof(Instance, color))});
+
+  this->graphicsPipeline = GraphicsPipeline::Builder(this->device)
+                               .setVertexShader(*vertexShader)
+                               .setFragmentShader(*fragmentShader)
+                               .setPipelineLayout(this->pipelineLayout.get())
+                               .setColorAttachmentFormats({colorFormat})
+                               .setDepthAttachmentFormat(depthFormat)
+                               .setVertexInput(bindings, attributes)
+                               .setDepthTest(true, true)
+                               .setCullMode(vk::CullModeFlagBits::eBack)
+                               .build();
+}
+
+void MeshRenderSystem::createInstanceBuffers() {
+  for (std::unique_ptr<Buffer>& buffer : this->instanceBuffers) {
+    buffer = std::make_unique<Buffer>(
+        this->device, sizeof(Instance), MAX_INSTANCES_PER_FRAME,
+        vk::BufferUsageFlagBits::eVertexBuffer,
+        vk::MemoryPropertyFlagBits::eHostVisible |
+            vk::MemoryPropertyFlagBits::eHostCoherent);
+    buffer->map();
+  }
+}
+
+}  // namespace sophia

engine/src/renderer/mesh_render_system.hpp

@@ -0,0 +1,80 @@
+#pragma once
+
+#include <array>
+#include <memory>
+#include <sophia/handles.hpp>
+#include <sophia/math.hpp>
+#include <span>
+
+#include "renderer/render_context.hpp"
+#include "resources/resource_registry.hpp"
+#include "vulkan/buffer.hpp"
+#include "vulkan/device.hpp"
+#include "vulkan/pipelines/graphics_pipeline.hpp"
+
+namespace sophia {
+
+/**
+ * Draws batches of opaque meshes, depth tested and back-face culled. Knows
+ * nothing about scenes: callers hand it instances grouped into runs that
+ * share a mesh.
+ *
+ * Unlit for now: each pixel is the vertex color times the instance color.
+ * Normals and UVs reach the vertex shader but aren't used yet.
+ *
+ * Instances are written to a per-frame host-visible buffer, so every
+ * render() call within one frame appends to it; call beginFrame() once per
+ * frame before any render().
+ */
+class MeshRenderSystem {
+ public:
+  // Layout must match the per-instance inputs in mesh.vert.
+  struct Instance {
+    glm::mat4 model{1.f};
+    glm::vec4 color{1.f};
+  };
+
+  // A run of consecutive instances of the same mesh.
+  struct Batch {
+    MeshHandle mesh;
+    u32 firstInstance;
+    u32 instanceCount;
+  };
+
+  static constexpr u32 MAX_INSTANCES_PER_FRAME = 32768;
+
+  MeshRenderSystem(const MeshRenderSystem&) = delete;
+  MeshRenderSystem& operator=(const MeshRenderSystem&) = delete;
+
+  MeshRenderSystem(Device& device, vk::Format colorFormat,
+                   vk::Format depthFormat, ResourceRegistry& resources);
+  ~MeshRenderSystem();
+
+  void beginFrame(u32 frameIndex);
+
+  void render(vk::CommandBuffer commandBuffer, const glm::mat4& viewProjection,
+              std::span<const Instance> instances,
+              std::span<const Batch> batches);
+
+ private:
+  struct PushConstantData {
+    glm::mat4 viewProjection{1.f};
+  };
+
+  void createPipelineLayout();
+  void createPipeline(vk::Format colorFormat, vk::Format depthFormat);
+  void createInstanceBuffers();
+
+  Device& device;
+  ResourceRegistry& resources;
+
+  vk::UniquePipelineLayout pipelineLayout;
+  std::unique_ptr<GraphicsPipeline> graphicsPipeline;
+
+  std::array<std::unique_ptr<Buffer>, RenderContext::MAX_FRAMES_IN_FLIGHT>
+      instanceBuffers;
+  u32 frameIndex = 0;
+  u32 instanceCursor = 0;
+};
+
+}  // namespace sophia

engine/src/renderer/model_render_system.cpp

@@ -25,8 +25,8 @@ ModelRenderSystem::ModelRenderSystem(Device& device,
                             .setStage(ShaderStage::FRAGMENT)
                             .build();
 
-  auto bindingDescriptions = Mesh::Vertex::getBindingDescriptions();
+  auto bindingDescriptions = Mesh::getBindingDescriptions();
-  auto attributeDescriptions = Mesh::Vertex::getAttributeDescriptions();
+  auto attributeDescriptions = Mesh::getAttributeDescriptions();
 
   this->graphicsPipeline =
       GraphicsPipeline::Builder(device)
@@ -44,10 +44,8 @@ ModelRenderSystem::~ModelRenderSystem() {
 
 void ModelRenderSystem::render(vk::CommandBuffer commandBuffer,
                                std::span<const MeshInstance> instances,
-                               const FrameInfo& frameInfo) {
+                               const glm::mat4& viewProjection) {
   ZoneScoped;
-  glm::mat4 viewProjection = frameInfo.camera.getViewProjection();
-
   this->graphicsPipeline->bind(commandBuffer);
 
   for (const MeshInstance& instance : instances) {

engine/src/renderer/model_render_system.hpp

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <memory>
-#include <sophia/frame_info.hpp>
+#include <sophia/math.hpp>
 #include <span>
 
 #include "renderer/render_context.hpp"
@@ -32,7 +32,7 @@ class ModelRenderSystem {
 
   void render(vk::CommandBuffer commandBuffer,
               std::span<const MeshInstance> instances,
-              const FrameInfo& frameInfo);
+              const glm::mat4& viewProjection);
 
  private:
   void createPipelineLayout();

engine/src/renderer/render_context.cpp

@@ -14,9 +14,13 @@ RenderContext::RenderContext(Window& window, Device& device)
     : window{window}, device{device} {
   createFrames();
   recreateSwapchain();
+  createTracyContext();
 }
 
-RenderContext::~RenderContext() { this->device.waitIdle(); }
+RenderContext::~RenderContext() {
+  this->device.waitIdle();
+  TracyVkDestroy(this->tracyContext);
+}
 
 vk::CommandBuffer RenderContext::beginFrame() {
   ZoneScoped;
@@ -75,6 +79,9 @@ vk::CommandBuffer RenderContext::beginFrame() {
     throw std::runtime_error("failed to begin recording command buffer");
   }
 
+  TracyVkCollect(this->tracyContext,
+                 static_cast<VkCommandBuffer>(frame.commandBuffer));
+
   return frame.commandBuffer;
 }
 
@@ -158,6 +165,27 @@ void RenderContext::recreateSwapchain() {
   this->imagesInFlight.assign(this->swapchain->imageCount(), vk::Fence{});
 }
 
+void RenderContext::createTracyContext() {
+#ifdef TRACY_ENABLE
+  // Tracy records and submits a one-off command buffer to line up GPU and CPU
+  // clocks, and waits for it.
+  vk::CommandBufferAllocateInfo allocInfo{this->device.getCommandPool(),
+                                          vk::CommandBufferLevel::ePrimary, 1};
+  vk::CommandBuffer commandBuffer =
+      this->device.get()->allocateCommandBuffers(allocInfo).front();
+
+  this->tracyContext = TracyVkContext(
+      static_cast<VkPhysicalDevice>(this->device.getPhysicalDevice()),
+      static_cast<VkDevice>(*this->device.get()),
+      static_cast<VkQueue>(this->device.getGraphicsQueue()),
+      static_cast<VkCommandBuffer>(commandBuffer));
+  TracyVkContextName(this->tracyContext, "Graphics", 8);
+
+  this->device.get()->freeCommandBuffers(this->device.getCommandPool(),
+                                         commandBuffer);
+#endif
+}
+
 void RenderContext::createFrames() {
   vk::CommandBufferAllocateInfo allocInfo{this->device.getCommandPool(),
                                           vk::CommandBufferLevel::ePrimary,

engine/src/renderer/render_context.hpp

@@ -6,6 +6,9 @@
 #include <vector>
 #include <vulkan/vulkan.hpp>
 
+/* AFTER VULKAN */
+#include <tracy/TracyVulkan.hpp>
+
 #include "vulkan/device.hpp"
 #include "vulkan/swapchain.hpp"
 #include "window.hpp"
@@ -35,11 +38,17 @@ class RenderContext {
     return this->swapchain->getImage(static_cast<int>(this->currentImageIndex));
   }
 
+  Image& getCurrentDepthImage() const {
+    return this->swapchain->getDepthImage(
+        static_cast<int>(this->currentImageIndex));
+  }
+
   vk::Extent2D getExtent() const { return this->swapchain->getExtent(); }
   vk::Format getImageFormat() const {
     return this->swapchain->getImageFormat();
   }
   u32 getFrameIndex() const { return this->currentFrameIndex; }
+  TracyVkCtx getTracyContext() const { return this->tracyContext; }
   u32 getImageCount() const {
     return static_cast<u32>(this->swapchain->imageCount());
   }
@@ -47,6 +56,7 @@ class RenderContext {
  private:
   void recreateSwapchain();
   void createFrames();
+  void createTracyContext();
 
   Window& window;
   Device& device;
@@ -58,6 +68,8 @@ class RenderContext {
   std::vector<vk::UniqueSemaphore> renderFinishedSemaphores;
   std::vector<vk::Fence> imagesInFlight;
 
+  TracyVkCtx tracyContext = nullptr;
+
   u32 currentFrameIndex = 0;
   u32 currentImageIndex = 0;
   bool isFrameStarted = false;

engine/src/renderer/render_graph.cpp

@@ -71,6 +71,10 @@ void RenderGraph::flush(vk::CommandBuffer commandBuffer,
 }
 
 void RenderGraph::recordPass(vk::CommandBuffer commandBuffer, Pass& pass) {
+  ZoneTransientN(cpuZone, pass.name.c_str(), true);
+  TracyVkZoneTransient(this->tracyContext, gpuZone,
+                       static_cast<VkCommandBuffer>(commandBuffer),
+                       pass.name.c_str(), this->tracyContext != nullptr);
   beginDebugLabel(commandBuffer, pass.name.c_str());
 
   PendingBarriers pending;
@@ -79,7 +83,7 @@ void RenderGraph::recordPass(vk::CommandBuffer commandBuffer, Pass& pass) {
   }
   this->flush(commandBuffer, pending);
 
-  if (pass.colorAttachments.empty()) {
+  if (pass.colorAttachments.empty() && !pass.depthAttachment) {
     pass.execute(commandBuffer);
   } else {
     this->recordRendering(commandBuffer, pass);
@@ -92,9 +96,10 @@ void RenderGraph::recordRendering(vk::CommandBuffer commandBuffer, Pass& pass) {
   std::vector<vk::RenderingAttachmentInfo> attachments;
   attachments.reserve(pass.colorAttachments.size());
 
-  vk::Extent3D imageExtent =
+  ImageRef sizedBy = pass.colorAttachments.empty()
-      this->images[pass.colorAttachments.front().image.index]
+                         ? pass.depthAttachment->image
-          .image->getExtent();
+                         : pass.colorAttachments.front().image;
+  vk::Extent3D imageExtent = this->images[sizedBy.index].image->getExtent();
   vk::Extent2D extent{imageExtent.width, imageExtent.height};
 
   for (const ColorAttachment& color : pass.colorAttachments) {
@@ -119,6 +124,24 @@ void RenderGraph::recordRendering(vk::CommandBuffer commandBuffer, Pass& pass) {
   renderingInfo.colorAttachmentCount = static_cast<u32>(attachments.size());
   renderingInfo.pColorAttachments = attachments.data();
 
+  vk::RenderingAttachmentInfo depthAttachment{};
+  if (pass.depthAttachment) {
+    const Image& image = *this->images[pass.depthAttachment->image.index].image;
+    SOPHIA_ASSERT(image.getExtent().width == extent.width &&
+                      image.getExtent().height == extent.height,
+                  "Pass", pass.name,
+                  "has a depth attachment of a different size");
+
+    depthAttachment.imageView = image.getView();
+    depthAttachment.imageLayout =
+        vk::ImageLayout::eDepthStencilAttachmentOptimal;
+    depthAttachment.loadOp = pass.depthAttachment->loadOp;
+    depthAttachment.storeOp = vk::AttachmentStoreOp::eStore;
+    depthAttachment.clearValue.depthStencil =
+        vk::ClearDepthStencilValue{pass.depthAttachment->clearDepth, 0};
+    renderingInfo.pDepthAttachment = &depthAttachment;
+  }
+
   commandBuffer.beginRendering(renderingInfo);
 
   vk::Viewport viewport{0.0f,
@@ -143,6 +166,15 @@ RenderGraph::PassBuilder& RenderGraph::PassBuilder::writeColor(
   return *this;
 }
 
+RenderGraph::PassBuilder& RenderGraph::PassBuilder::writeDepth(
+    ImageRef image, vk::AttachmentLoadOp loadOp, float clearDepth) {
+  SOPHIA_ASSERT(!this->pass.depthAttachment, "Pass", this->pass.name,
+                "already has a depth attachment");
+  this->use(image, Access::DepthWrite);
+  this->pass.depthAttachment = DepthAttachment{image, loadOp, clearDepth};
+  return *this;
+}
+
 RenderGraph::PassBuilder& RenderGraph::PassBuilder::sample(ImageRef image) {
   return this->use(image, Access::SampledRead);
 }

engine/src/renderer/render_graph.hpp

@@ -2,10 +2,13 @@
 
 #include <array>
 #include <functional>
+#include <optional>
 #include <sophia/types.hpp>
 #include <string>
 #include <vector>
 #include <vulkan/vulkan.hpp>
+// After Vulkan, which it expects to already be declared.
+#include <tracy/TracyVulkan.hpp>
 
 #include "vulkan/access.hpp"
 #include "vulkan/image.hpp"
@@ -31,7 +34,7 @@ using ClearColor = std::array<float, 4>;
  * buffer. Passes run in the order they were added; the graph's job is to
  * work out the barriers and layout transitions between them from what each
  * pass says it does to each image, and to begin/end rendering for passes that
- * write color attachments.
+ * write color or depth attachments.
  *
  * Built fresh every frame:
  *
@@ -53,7 +56,8 @@ class RenderGraph {
   using SetupFn = std::function<void(PassBuilder&)>;
   using ExecuteFn = std::function<void(vk::CommandBuffer)>;
 
-  RenderGraph() = default;
+  explicit RenderGraph(TracyVkCtx tracyContext = nullptr)
+      : tracyContext{tracyContext} {}
 
   RenderGraph(const RenderGraph&) = delete;
   RenderGraph& operator=(const RenderGraph&) = delete;
@@ -67,8 +71,8 @@ class RenderGraph {
   /**
    * Adds a pass. `setup` runs immediately and declares what the pass does to
    * images; `execute` runs later, from execute(), with the barriers already
-   * recorded and (if the pass writes color) rendering begun. `name` labels
+   * recorded and (if the pass writes color or depth) rendering begun. `name`
-   * the pass's commands in debugging tools such as RenderDoc.
+   * labels the pass's commands in debugging tools such as RenderDoc.
    */
   void addPass(std::string name, const SetupFn& setup, ExecuteFn execute);
 
@@ -89,10 +93,17 @@ class RenderGraph {
     ClearColor clearColor;
   };
 
+  struct DepthAttachment {
+    ImageRef image;
+    vk::AttachmentLoadOp loadOp;
+    float clearDepth;
+  };
+
   struct Pass {
     std::string name;
     std::vector<ImageUse> uses;
     std::vector<ColorAttachment> colorAttachments;
+    std::optional<DepthAttachment> depthAttachment;
     ExecuteFn execute;
   };
 
@@ -113,6 +124,7 @@ class RenderGraph {
   void recordPass(vk::CommandBuffer commandBuffer, Pass& pass);
   void recordRendering(vk::CommandBuffer commandBuffer, Pass& pass);
 
+  TracyVkCtx tracyContext;
   std::vector<ImportedImage> images;
   std::vector<Pass> passes;
 };
@@ -129,6 +141,15 @@ class RenderGraph::PassBuilder {
       vk::AttachmentLoadOp loadOp = vk::AttachmentLoadOp::eClear,
       ClearColor clearColor = {0.f, 0.f, 0.f, 1.f});
 
+  /**
+   * Renders with `image` as the depth attachment, which must be the same size
+   * as any color attachments. At most one per pass.
+   */
+  PassBuilder& writeDepth(
+      ImageRef image,
+      vk::AttachmentLoadOp loadOp = vk::AttachmentLoadOp::eClear,
+      float clearDepth = 1.f);
+
   /** Samples `image` in a shader. */
   PassBuilder& sample(ImageRef image);
 

engine/src/renderer/renderer.cpp

@@ -0,0 +1,9 @@
+#include "renderer/renderer.hpp"
+
+namespace sophia {
+
+Renderer::Renderer() {}
+
+Renderer::~Renderer() {}
+
+}  // namespace sophia

engine/src/renderer/renderer.hpp

@@ -0,0 +1,91 @@
+#pragma once
+
+#include <sophia/handles.hpp>
+#include <sophia/math.hpp>
+#include <sophia/types.hpp>
+#include <string>
+#include <vector>
+
+#include "vulkan/buffer.hpp"
+
+namespace sophia {
+
+struct DrawPacket {
+  /* Geometry */
+  // BufferHandle vertexBuffer;
+  // BufferHandle indexBuffer;
+  u32 indexCount;
+  u32 firstIndex;
+
+  /* Shader & state */
+  // PipelineHandle pipelineState; // Contains shaders, blend state, depth
+  // settings
+
+  /* Bindings */
+  // DescriptorSetHandle resourceBindings;  // Textures, Uniform Buffers,
+  // Storage Buffers
+
+  /* Transform / Constants */
+  u32 pushConstantData[16];
+};
+
+struct RenderView {
+  mat4 view;
+  mat4 projection;
+  vec2 viewport;
+
+  RenderTargetHandle target;
+};
+
+// struct ComputePacket {
+//   ComputePipelineHandle pipeline;
+//   DescriptorSetHandle
+//       resourceBindings;  // Includes storage buffers, uniforms, textures
+
+//   // Grid dimensions
+//   uint32_t groupCountX = 1;
+//   uint32_t groupCountY = 1;
+//   uint32_t groupCountZ = 1;
+
+//   // Optional push constants for dynamic per-dispatch parameters
+//   uint8_t pushConstants[64];
+//   uint32_t pushConstantSize = 0;
+// };
+
+// !TODO move to render graph
+enum class RenderPassType { Graphics, Compute };
+
+// !TODO move to render graph (???)
+struct RenderPass {
+  std::string name;
+  RenderPassType type;
+
+  // Declared for automatic barrier injection & resource synchronization
+  std::vector<Buffer> readBuffers;   // BufferHandle instead?
+  std::vector<Buffer> writeBuffers;  // BufferHandle instead?
+
+  // Commands in this pass
+  // std::vector<ComputePacket> computeDispatches;
+  std::vector<DrawPacket> opaqueDrawPackets;
+  std::vector<DrawPacket> transparentDrawPackets;
+};
+
+struct RenderPacket {
+  RenderView view;
+  std::vector<RenderPass> passes;
+};
+
+class Renderer {
+ public:
+  Renderer(const Renderer&) = delete;
+  Renderer& operator=(const Renderer&) = delete;
+
+  Renderer();
+  ~Renderer();
+
+  // PipelineHandle createPipeline();
+
+ private:
+};
+
+}  // namespace sophia

engine/src/renderer/scene_renderer.cpp

@@ -13,73 +13,149 @@ SceneRenderer::SceneRenderer(const SceneRegistry& sceneRegistry,
                              vk::Format colorFormat)
     : sceneRegistry{sceneRegistry},
       resources{resources},
-      spriteRenderSystem{device, colorFormat, resources} {}
+      meshRenderSystem{device, colorFormat,
+                       resources.renderTargetPool.getDepthFormat(), resources},
+      spriteRenderSystem{device, colorFormat,
+                         resources.renderTargetPool.getDepthFormat(),
+                         resources} {}
 
 void SceneRenderer::beginFrame(u32 frameIndex) {
   ZoneScoped;
+  this->meshRenderSystem.beginFrame(frameIndex);
   this->spriteRenderSystem.beginFrame(frameIndex);
 }
 
 void SceneRenderer::render(vk::CommandBuffer commandBuffer,
-                           const SceneView& sceneView, Entity camera) {
+                           const SceneView& sceneView, Entity camera,
+                           vk::Extent2D extent) {
   ZoneScoped;
   SOPHIA_ASSERT(camera.hasComponent<CameraComponent>(),
                 "camera does not have camera component!");
 
-  vk::Extent2D extent =
-      this->resources.renderTargetPool.get(sceneView.target).getExtent();
   float aspect =
       static_cast<float>(extent.width) / static_cast<float>(extent.height);
 
-  glm::mat4 viewProjection =
+  glm::mat4 view =
-      camera.getComponent<CameraComponent>().getViewProjection(
+      CameraComponent::getView(camera.getComponent<TransformComponent>());
-          camera.getComponent<TransformComponent>(), aspect);
+  glm::mat4 projection =
+      camera.getComponent<CameraComponent>().getProjection(aspect);
 
-  renderSprites(commandBuffer, this->sceneRegistry.get(sceneView.scene),
+  const Scene& scene = this->sceneRegistry.get(sceneView.scene);
-                viewProjection);
+  glm::mat4 viewProjection = projection * view;
 
-  // TODO: meshes. Group MeshComponent entities by mesh and draw each group
+  // Opaque first, so sprites blend over the meshes behind them.
-  // (instanced), as sprites are grouped by texture.
+  renderMeshes(commandBuffer, scene, viewProjection);
+  renderSprites(commandBuffer, scene, view, viewProjection);
+}
+
+void SceneRenderer::renderMeshes(vk::CommandBuffer commandBuffer,
+                                 const Scene& scene,
+                                 const glm::mat4& viewProjection) {
+  ZoneScoped;
+  this->meshDrawItems.clear();
+
+  {
+    ZoneScopedN("meshes: gather");
+    auto meshes =
+        scene.registry.view<const TransformComponent, const MeshComponent>();
+    for (auto [entity, transform, mesh] : meshes.each()) {
+      if (!this->resources.meshPool.isAlive(mesh.handle)) {
+        continue;
+      }
+      this->meshDrawItems.push_back(
+          {mesh.handle, {transform.mat4(), mesh.color}});
+    }
+  }
+
+  {
+    ZoneScopedN("meshes: sort");
+    // Opaque, so order only matters for batching: one batch per mesh.
+    std::ranges::sort(this->meshDrawItems, {},
+                      [](const MeshDrawItem& item) { return item.mesh; });
+  }
+
+  {
+    ZoneScopedN("meshes: batch");
+    this->meshInstances.clear();
+    this->meshBatches.clear();
+    for (const MeshDrawItem& item : this->meshDrawItems) {
+      auto index = static_cast<u32>(this->meshInstances.size());
+      this->meshInstances.push_back(item.instance);
+
+      if (this->meshBatches.empty() ||
+          this->meshBatches.back().mesh != item.mesh) {
+        this->meshBatches.push_back({item.mesh, index, 0});
+      }
+      this->meshBatches.back().instanceCount++;
+    }
+  }
+
+  TracyPlot("mesh instances", static_cast<int64_t>(this->meshInstances.size()));
+  TracyPlot("mesh batches", static_cast<int64_t>(this->meshBatches.size()));
+
+  this->meshRenderSystem.render(commandBuffer, viewProjection,
+                                this->meshInstances, this->meshBatches);
 }
 
 void SceneRenderer::renderSprites(vk::CommandBuffer commandBuffer,
-                                  const Scene& scene,
+                                  const Scene& scene, const glm::mat4& view,
                                   const glm::mat4& viewProjection) {
+  ZoneScoped;
   this->spriteDrawItems.clear();
 
-  auto view =
+  {
-      scene.registry.view<const TransformComponent, const SpriteComponent>();
+    ZoneScopedN("sprites: gather");
-  for (auto [entity, transform, sprite] : view.each()) {
+    auto sprites =
-    TextureHandle texture = this->resources.texturePool.isAlive(sprite.texture)
+        scene.registry.view<const TransformComponent, const SpriteComponent>();
-                                ? sprite.texture
+    for (auto [entity, transform, sprite] : sprites.each()) {
-                                : this->resources.whiteTexture;
+      TextureHandle texture =
+          this->resources.texturePool.isAlive(sprite.texture)
+              ? sprite.texture
+              : this->resources.whiteTexture;
 
-    this->spriteDrawItems.push_back(
+      // Distance in front of the camera, which looks down view-space -Z.
-        {sprite.sortOrder,
+      float depth = -(view * glm::vec4{transform.position, 1.f}).z;
-         transform.position.z,
-         texture,
-         {sprite.getModel(transform), sprite.color, sprite.uvRect}});
-  }
 
-  // Texture is the last key so that sprites whose order doesn't matter
+      this->spriteDrawItems.push_back(
-  // relative to each other still end up in as few batches as possible.
+          {sprite.sortOrder,
-  std::ranges::sort(this->spriteDrawItems, {}, [](const SpriteDrawItem& item) {
+           depth,
-    return std::tuple{item.sortOrder, item.depth, item.texture};
+           texture,
-  });
+           {sprite.getModel(transform), sprite.color, sprite.uvRect}});
-
-  this->spriteInstances.clear();
-  this->spriteBatches.clear();
-  for (const SpriteDrawItem& item : this->spriteDrawItems) {
-    auto index = static_cast<u32>(this->spriteInstances.size());
-    this->spriteInstances.push_back(item.instance);
-
-    if (this->spriteBatches.empty() ||
-        this->spriteBatches.back().texture != item.texture) {
-      this->spriteBatches.push_back({item.texture, index, 0});
     }
-    this->spriteBatches.back().instanceCount++;
   }
 
+  {
+    ZoneScopedN("sprites: sort");
+    // Within a sortOrder, back to front, so nearer sprites blend over farther
+    // ones. Texture is the last key so that sprites whose order doesn't
+    // matter relative to each other still end up in as few batches as
+    // possible.
+    std::ranges::sort(
+        this->spriteDrawItems, {}, [](const SpriteDrawItem& item) {
+          return std::tuple{item.sortOrder, -item.depth, item.texture};
+        });
+  }
+
+  {
+    ZoneScopedN("sprites: batch");
+    this->spriteInstances.clear();
+    this->spriteBatches.clear();
+    for (const SpriteDrawItem& item : this->spriteDrawItems) {
+      auto index = static_cast<u32>(this->spriteInstances.size());
+      this->spriteInstances.push_back(item.instance);
+
+      if (this->spriteBatches.empty() ||
+          this->spriteBatches.back().texture != item.texture) {
+        this->spriteBatches.push_back({item.texture, index, 0});
+      }
+      this->spriteBatches.back().instanceCount++;
+    }
+  }
+
+  TracyPlot("sprite instances",
+            static_cast<int64_t>(this->spriteInstances.size()));
+  TracyPlot("sprite batches", static_cast<int64_t>(this->spriteBatches.size()));
+
   this->spriteRenderSystem.render(commandBuffer, viewProjection,
                                   this->spriteInstances, this->spriteBatches);
 }

engine/src/renderer/scene_renderer.hpp

@@ -4,6 +4,7 @@
 #include <sophia/scene_view.hpp>
 #include <vector>
 
+#include "renderer/mesh_render_system.hpp"
 #include "renderer/sprite_render_system.hpp"
 #include "resources/resource_registry.hpp"
 
@@ -27,27 +28,39 @@ class SceneRenderer {
 
   // Records `sceneView` as seen through `camera` (an entity of the view's
   // scene with a CameraComponent) into `commandBuffer`. Rendering into the
-  // view's target must already have begun.
+  // view's target, which is `extent` in size, must already have begun.
   void render(vk::CommandBuffer commandBuffer, const SceneView& sceneView,
-              Entity camera);
+              Entity camera, vk::Extent2D extent);
 
  private:
+  struct MeshDrawItem {
+    MeshHandle mesh;
+    MeshRenderSystem::Instance instance;
+  };
+
   struct SpriteDrawItem {
     s32 sortOrder;
+    // Distance in front of the camera.
     float depth;
     TextureHandle texture;
     SpriteRenderSystem::Instance instance;
   };
 
+  void renderMeshes(vk::CommandBuffer commandBuffer, const Scene& scene,
+                    const glm::mat4& viewProjection);
   void renderSprites(vk::CommandBuffer commandBuffer, const Scene& scene,
-                     const glm::mat4& viewProjection);
+                     const glm::mat4& view, const glm::mat4& viewProjection);
 
   const SceneRegistry& sceneRegistry;
   ResourceRegistry& resources;
 
+  MeshRenderSystem meshRenderSystem;
   SpriteRenderSystem spriteRenderSystem;
 
   // Reused across frames to avoid reallocating.
+  std::vector<MeshDrawItem> meshDrawItems;
+  std::vector<MeshRenderSystem::Instance> meshInstances;
+  std::vector<MeshRenderSystem::Batch> meshBatches;
   std::vector<SpriteDrawItem> spriteDrawItems;
   std::vector<SpriteRenderSystem::Instance> spriteInstances;
   std::vector<SpriteRenderSystem::Batch> spriteBatches;

engine/src/renderer/sprite_render_system.cpp

@@ -16,11 +16,12 @@ constexpr u32 VERTICES_PER_SPRITE = 6;
 }  // namespace
 
 SpriteRenderSystem::SpriteRenderSystem(Device& device, vk::Format colorFormat,
+                                       vk::Format depthFormat,
                                        ResourceRegistry& resources)
     : device{device}, resources{resources} {
   createDescriptors();
   createPipelineLayout();
-  createPipeline(colorFormat);
+  createPipeline(colorFormat, depthFormat);
   createInstanceBuffers();
 }
 
@@ -147,7 +148,8 @@ void SpriteRenderSystem::createPipelineLayout() {
   }
 }
 
-void SpriteRenderSystem::createPipeline(vk::Format colorFormat) {
+void SpriteRenderSystem::createPipeline(vk::Format colorFormat,
+                                        vk::Format depthFormat) {
   auto vertexShader = Shader::Builder()
                           .fromSPIRV(shaders::sprite_vert_spv)
                           .setStage(ShaderStage::VERTEX)
@@ -172,14 +174,17 @@ void SpriteRenderSystem::createPipeline(vk::Format colorFormat) {
   attributes.push_back({5, 0, vk::Format::eR32G32B32A32Sfloat,
                         static_cast<u32>(offsetof(Instance, uvRect))});
 
-  this->graphicsPipeline = GraphicsPipeline::Builder(this->device)
+  this->graphicsPipeline =
-                               .setVertexShader(*vertexShader)
+      GraphicsPipeline::Builder(this->device)
-                               .setFragmentShader(*fragmentShader)
+          .setVertexShader(*vertexShader)
-                               .setPipelineLayout(this->pipelineLayout.get())
+          .setFragmentShader(*fragmentShader)
-                               .setColorAttachmentFormats({colorFormat})
+          .setPipelineLayout(this->pipelineLayout.get())
-                               .setVertexInput(bindings, attributes)
+          .setColorAttachmentFormats({colorFormat})
-                               .setAlphaBlending()
+          .setDepthAttachmentFormat(depthFormat)
-                               .build();
+          .setVertexInput(bindings, attributes)
+          .setAlphaBlending()
+          .setDepthTest(true, false, vk::CompareOp::eLessOrEqual)
+          .build();
 }
 
 void SpriteRenderSystem::createInstanceBuffers() {

engine/src/renderer/sprite_render_system.hpp

@@ -20,6 +20,8 @@ namespace sophia {
 /**
  * Draws batches of textured quads. Knows nothing about scenes: callers hand
  * it instances already in draw order, grouped into runs that share a texture.
+ * Sprites are depth tested, so opaque geometry in front hides them, but
+ * don't write depth, since they blend.
  *
  * Instances are written to a per-frame host-visible buffer, so every
  * render() call within one frame appends to it; call beginFrame() once per
@@ -47,7 +49,7 @@ class SpriteRenderSystem {
   SpriteRenderSystem& operator=(const SpriteRenderSystem&) = delete;
 
   SpriteRenderSystem(Device& device, vk::Format colorFormat,
-                     ResourceRegistry& resources);
+                     vk::Format depthFormat, ResourceRegistry& resources);
   ~SpriteRenderSystem();
 
   void beginFrame(u32 frameIndex);
@@ -68,7 +70,7 @@ class SpriteRenderSystem {
 
   void createDescriptors();
   void createPipelineLayout();
-  void createPipeline(vk::Format colorFormat);
+  void createPipeline(vk::Format colorFormat, vk::Format depthFormat);
   void createInstanceBuffers();
 
   vk::DescriptorSet getDescriptorSet(TextureHandle handle);

engine/src/resources/mesh.cpp

@@ -5,35 +5,32 @@
 
 namespace sophia {
 
-std::vector<vk::VertexInputBindingDescription>
+std::vector<vk::VertexInputBindingDescription> Mesh::getBindingDescriptions() {
-Mesh::Vertex::getBindingDescriptions() {
+  return {{0, sizeof(MeshVertex), vk::VertexInputRate::eVertex}};
-  std::vector<vk::VertexInputBindingDescription> bindingDescriptions(1);
-  bindingDescriptions[0].binding = 0;
-  bindingDescriptions[0].stride = sizeof(Vertex);
-  bindingDescriptions[0].inputRate = vk::VertexInputRate::eVertex;
-
-  return bindingDescriptions;
 }
 
 std::vector<vk::VertexInputAttributeDescription>
-Mesh::Vertex::getAttributeDescriptions() {
+Mesh::getAttributeDescriptions() {
-  std::vector<vk::VertexInputAttributeDescription> attributeDescriptions{};
+  return {
-
+      {0, 0, vk::Format::eR32G32B32Sfloat, offsetof(MeshVertex, position)},
-  attributeDescriptions.push_back(
+      {1, 0, vk::Format::eR32G32B32Sfloat, offsetof(MeshVertex, normal)},
-      {0, 0, vk::Format::eR32G32Sfloat, offsetof(Vertex, position)});
+      {2, 0, vk::Format::eR32G32Sfloat, offsetof(MeshVertex, uv)},
-  attributeDescriptions.push_back(
+      {3, 0, vk::Format::eR32G32B32A32Sfloat, offsetof(MeshVertex, color)},
-      {1, 0, vk::Format::eR32G32B32Sfloat, offsetof(Vertex, color)});
+  };
-  // attributeDescriptions.push_back(
-  //     {2, 0, vk::Format::eR32G32B32Sfloat, offsetof(Vertex, normal)});
-  // attributeDescriptions.push_back(
-  //     {3, 0, vk::Format::eR32G32Sfloat, offsetof(Vertex, uv)});
-
-  return attributeDescriptions;
 }
 
-Mesh::Mesh(Device& device, const Builder& builder) : device{device} {
+Mesh::Mesh(Device& device, const MeshData& data) : device{device} {
-  createVertexBuffers(builder.vertices);
+  if (!data.vertices.empty()) {
-  createIndexBuffers(builder.indices);
+    this->bounds = {data.vertices.front().position,
+                    data.vertices.front().position};
+    for (const MeshVertex& vertex : data.vertices) {
+      this->bounds.min = glm::min(this->bounds.min, vertex.position);
+      this->bounds.max = glm::max(this->bounds.max, vertex.position);
+    }
+  }
+
+  createVertexBuffers(data.vertices);
+  createIndexBuffers(data.indices);
 }
 
 Mesh::~Mesh() = default;
@@ -49,15 +46,17 @@ void Mesh::bind(vk::CommandBuffer commandBuffer) const {
   }
 }
 
-void Mesh::draw(vk::CommandBuffer commandBuffer) const {
+void Mesh::draw(vk::CommandBuffer commandBuffer, u32 instanceCount,
+                u32 firstInstance) const {
   if (this->hasIndexBuffer) {
-    commandBuffer.drawIndexed(this->indexCount, 1, 0, 0, 0);
+    commandBuffer.drawIndexed(this->indexCount, instanceCount, 0, 0,
+                              firstInstance);
   } else {
-    commandBuffer.draw(this->vertexCount, 1, 0, 0);
+    commandBuffer.draw(this->vertexCount, instanceCount, 0, firstInstance);
   }
 }
 
-void Mesh::createVertexBuffers(const std::vector<Vertex>& vertices) {
+void Mesh::createVertexBuffers(const std::vector<MeshVertex>& vertices) {
   this->vertexCount = static_cast<u32>(vertices.size());
   SOPHIA_ASSERT(this->vertexCount >= 3, "vertex count must be at least 3");
 

engine/src/resources/mesh.hpp

@@ -1,8 +1,10 @@
 #pragma once
 
 #include <memory>
+#include <sophia/aabb.hpp>
 #include <sophia/handles.hpp>
 #include <sophia/math.hpp>
+#include <sophia/mesh_data.hpp>
 #include <sophia/types.hpp>
 #include <vector>
 
@@ -13,47 +15,33 @@ namespace sophia {
 
 class Mesh {
  public:
-  struct Vertex {
+  // Binding 0 (per vertex, MeshVertex) for pipelines that draw meshes.
-    glm::vec2 position{};
+  static std::vector<vk::VertexInputBindingDescription>
-    glm::vec3 color{};
+  getBindingDescriptions();
-    // glm::vec3 normal{};
+  static std::vector<vk::VertexInputAttributeDescription>
-    // glm::vec2 uv{};
+  getAttributeDescriptions();
 
-    static std::vector<vk::VertexInputBindingDescription>
+  Mesh(Device& device, const MeshData& data);
-    getBindingDescriptions();
-    static std::vector<vk::VertexInputAttributeDescription>
-    getAttributeDescriptions();
-
-    // bool operator==(const Vertex& other) const {
-    //   return position == other.position && color == other.color;
-    // }
-  };
-
-  struct Builder {
-    std::vector<Vertex> vertices{};
-    std::vector<uint32_t> indices{};
-
-    // void loadModel(const std::string& filepath);
-  };
-
-  Mesh(Device& device, const Mesh::Builder& builder);
   ~Mesh();
 
   Mesh(const Mesh&) = delete;
   Mesh& operator=(const Mesh&) = delete;
 
-  // static std::unique_ptr<Mesh> createMeshFromFile(
+  // Bounds of the vertices, in the mesh's own space.
-  //     Device& device, const std::string& filepath);
+  const AABB& getBounds() const { return this->bounds; }
 
   void bind(vk::CommandBuffer commandBuffer) const;
-  void draw(vk::CommandBuffer commandBuffer) const;
+  void draw(vk::CommandBuffer commandBuffer, u32 instanceCount = 1,
+            u32 firstInstance = 0) const;
 
  private:
-  void createVertexBuffers(const std::vector<Vertex>& vertices);
+  void createVertexBuffers(const std::vector<MeshVertex>& vertices);
   void createIndexBuffers(const std::vector<u32>& indices);
 
   Device& device;
 
+  AABB bounds;
+
   std::unique_ptr<Buffer> vertexBuffer;
   u32 vertexCount;
 

engine/src/resources/pools/render_target_pool.cpp

@@ -5,10 +5,16 @@
 namespace sophia {
 
 RenderTargetPool::RenderTargetPool(Device& device, vk::Format format)
-    : device{device}, format{format} {}
+    : device{device},
+      format{format},
+      // Depth-only formats, so the images have no stencil aspect to track.
+      depthFormat{device.findSupportedFormat(
+          {vk::Format::eD32Sfloat, vk::Format::eX8D24UnormPack32},
+          vk::ImageTiling::eOptimal,
+          vk::FormatFeatureFlagBits::eDepthStencilAttachment)} {}
 
 RenderTargetHandle RenderTargetPool::create(u32 width, u32 height) {
-  return pool.create(device, format, width, height);
+  return pool.create(device, format, depthFormat, width, height);
 }
 
 void RenderTargetPool::release(RenderTargetHandle handle) {

engine/src/resources/pools/render_target_pool.hpp

@@ -24,11 +24,15 @@ class RenderTargetPool {
 
   bool isAlive(RenderTargetHandle handle) const { return pool.isAlive(handle); }
 
+  vk::Format getFormat() const { return format; }
+  vk::Format getDepthFormat() const { return depthFormat; }
+
   void applyPendingResizes();
 
  private:
   Device& device;
   vk::Format format;
+  vk::Format depthFormat;
 
   Pool<RenderTarget> pool{"RenderTarget"};
 };

engine/src/resources/primitives.cpp

@@ -0,0 +1,55 @@
+#include <array>
+#include <sophia/primitives.hpp>
+
+namespace sophia::primitives {
+
+MeshData cube(float size, vec4 color) {
+  struct Face {
+    vec3 normal;
+    // Axes across the face, with u x v = normal, so corners taken
+    // counter-clockwise in (u, v) wind counter-clockwise seen from outside.
+    vec3 u;
+    vec3 v;
+  };
+
+  constexpr std::array<Face, 6> FACES{{
+      {{1.f, 0.f, 0.f}, {0.f, 0.f, -1.f}, {0.f, 1.f, 0.f}},
+      {{-1.f, 0.f, 0.f}, {0.f, 0.f, 1.f}, {0.f, 1.f, 0.f}},
+      {{0.f, 1.f, 0.f}, {1.f, 0.f, 0.f}, {0.f, 0.f, -1.f}},
+      {{0.f, -1.f, 0.f}, {1.f, 0.f, 0.f}, {0.f, 0.f, 1.f}},
+      {{0.f, 0.f, 1.f}, {1.f, 0.f, 0.f}, {0.f, 1.f, 0.f}},
+      {{0.f, 0.f, -1.f}, {-1.f, 0.f, 0.f}, {0.f, 1.f, 0.f}},
+  }};
+
+  constexpr std::array<vec2, 4> CORNERS{vec2{-1.f, -1.f}, vec2{1.f, -1.f},
+                                        vec2{1.f, 1.f}, vec2{-1.f, 1.f}};
+
+  float half = size / 2.f;
+
+  MeshData data;
+  data.vertices.reserve(FACES.size() * CORNERS.size());
+  data.indices.reserve(FACES.size() * 6);
+
+  for (const Face& face : FACES) {
+    auto base = static_cast<u32>(data.vertices.size());
+
+    for (vec2 corner : CORNERS) {
+      MeshVertex vertex;
+      vertex.position =
+          (face.normal + corner.x * face.u + corner.y * face.v) * half;
+      vertex.normal = face.normal;
+      // Texture v runs down while the face's v runs up.
+      vertex.uv = {(corner.x + 1.f) / 2.f, (1.f - corner.y) / 2.f};
+      vertex.color = color;
+      data.vertices.push_back(vertex);
+    }
+
+    for (u32 index : {0u, 1u, 2u, 2u, 3u, 0u}) {
+      data.indices.push_back(base + index);
+    }
+  }
+
+  return data;
+}
+
+}  // namespace sophia::primitives

engine/src/resources/render_target.cpp

@@ -4,9 +4,9 @@
 
 namespace sophia {
 
-RenderTarget::RenderTarget(Device& device, vk::Format format, u32 width,
+RenderTarget::RenderTarget(Device& device, vk::Format format,
-                           u32 height)
+                           vk::Format depthFormat, u32 width, u32 height)
-    : device{device}, format{format} {
+    : device{device}, format{format}, depthFormat{depthFormat} {
   create(std::max(width, 1u), std::max(height, 1u));
 }
 
@@ -46,8 +46,17 @@ void RenderTarget::create(u32 width, u32 height) {
                     .asColorAttachment()
                     .withView()
                     .build();
+  this->depthImage = Image::Builder(this->device)
+                         .setExtent(width, height)
+                         .asDepthAttachment()
+                         .setFormat(this->depthFormat)
+                         .withView()
+                         .build();
 }
 
-void RenderTarget::destroy() { this->image.reset(); }
+void RenderTarget::destroy() {
+  this->image.reset();
+  this->depthImage.reset();
+}
 
 }  // namespace sophia

engine/src/resources/render_target.hpp

@@ -11,20 +11,22 @@
 namespace sophia {
 
 /**
- * A place rendering can go. Currently always backed by an offscreen color
+ * A place rendering can go: an offscreen color image, plus a depth image of
- * image.
+ * the same size.
  *
  * Owned by the ResourceRegistry and addressed through a RenderTargetHandle.
  */
 class RenderTarget {
  public:
-  RenderTarget(Device& device, vk::Format format, u32 width, u32 height);
+  RenderTarget(Device& device, vk::Format format, vk::Format depthFormat,
+               u32 width, u32 height);
   ~RenderTarget();
 
   RenderTarget(const RenderTarget&) = delete;
   RenderTarget& operator=(const RenderTarget&) = delete;
 
   Image& getImage() const { return *this->image; }
+  Image& getDepthImage() const { return *this->depthImage; }
 
   vk::Extent2D getExtent() const;
   u32 getVersion() const { return this->version; }
@@ -43,8 +45,10 @@ class RenderTarget {
 
   Device& device;
   vk::Format format;
+  vk::Format depthFormat;
 
   std::unique_ptr<Image> image;
+  std::unique_ptr<Image> depthImage;
 
   std::optional<vk::Extent2D> pendingExtent;
   u32 version = 0;

engine/src/resources/resource_registry_ref.cpp

@@ -14,7 +14,7 @@ MeshHandle ResourceRegistryRef::load<Mesh>(const std::string& path) {
   (void)path;
   SOPHIA_ASSERT(false,
                 "Mesh::load(path) is not implemented yet - no model file "
-                "format is supported; build one via Mesh::Builder for now");
+                "format is supported; build a MeshData instead");
   return MeshHandle{};
 }
 
@@ -40,6 +40,8 @@ TextureHandle ResourceRegistryRef::load<Texture>(const std::string& path) {
 
 template <>
 void ResourceRegistryRef::release<Mesh>(MeshHandle handle) {
+  // Frames in flight may still be drawing it.
+  registry->device.waitIdle();
   registry->meshPool.release(handle);
 }
 
@@ -57,17 +59,9 @@ void ResourceRegistryRef::release<Texture>(TextureHandle handle) {
   registry->texturePool.release(handle);
 }
 
-MeshHandle ResourceRegistryRef::createResource(
+MeshHandle ResourceRegistryRef::createResource(std::type_identity<Mesh>,
-    std::type_identity<Mesh>, std::vector<CanvasVertex> vertices,
+                                               const MeshData& data) {
-    std::vector<u32> indices) {
+  return registry->meshPool.create(registry->device, data);
-  Mesh::Builder builder{};
-  builder.vertices.reserve(vertices.size());
-  for (const CanvasVertex& vertex : vertices) {
-    builder.vertices.push_back({vertex.position, vertex.color});
-  }
-  builder.indices = std::move(indices);
-
-  return registry->meshPool.create(registry->device, builder);
 }
 
 RenderTargetHandle ResourceRegistryRef::createResource(
@@ -92,6 +86,14 @@ glm::vec2 ResourceRegistryRef::getExtent(RenderTargetHandle handle) const {
   return {static_cast<float>(extent.width), static_cast<float>(extent.height)};
 }
 
+AABB ResourceRegistryRef::getBounds(MeshHandle handle) const {
+  return registry->meshPool.get(handle).getBounds();
+}
+
+bool ResourceRegistryRef::isAlive(MeshHandle handle) const {
+  return registry->meshPool.isAlive(handle);
+}
+
 bool ResourceRegistryRef::isAlive(RenderTargetHandle handle) const {
   return registry->renderTargetPool.isAlive(handle);
 }

engine/src/scene/scene_render_packet_builder.cpp

@@ -0,0 +1,9 @@
+#include "scene/scene_render_packet_builder.hpp"
+
+namespace sophia {
+
+void SceneRenderPacketBuilder::build(SceneHandle sceneHandle,
+                                     RenderTargetHandle renderTargetHandle,
+                                     RenderPacket& renderPacket) {}
+
+}  // namespace sophia

engine/src/scene/scene_render_packet_builder.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <sophia/handles.hpp>
+
+#include "renderer/renderer.hpp"
+
+namespace sophia {
+
+class SceneRenderPacketBuilder {
+ public:
+  static void build(SceneHandle sceneHandle,
+                    RenderTargetHandle renderTargetHandle,
+                    RenderPacket& renderPacket);
+};
+
+}  // namespace sophia

engine/src/shaders/fullscreen.vert.spv.h

@@ -6,95 +6,66 @@
 namespace sophia::shaders {
 
 inline constexpr std::array<uint32_t, 355> fullscreen_vert_spv = {
-    0x07230203, 0x00010000, 0x000d000b, 0x00000032,
+    0x07230203, 0x00010000, 0x000d000b, 0x00000032, 0x00000000, 0x00020011,
-    0x00000000, 0x00020011, 0x00000001, 0x0006000b,
+    0x00000001, 0x0006000b, 0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
-    0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
+    0x00000000, 0x0003000e, 0x00000000, 0x00000001, 0x0008000f, 0x00000000,
-    0x00000000, 0x0003000e, 0x00000000, 0x00000001,
+    0x00000004, 0x6e69616d, 0x00000000, 0x00000018, 0x00000022, 0x0000002c,
-    0x0008000f, 0x00000000, 0x00000004, 0x6e69616d,
+    0x00030003, 0x00000002, 0x000001c2, 0x000a0004, 0x475f4c47, 0x4c474f4f,
-    0x00000000, 0x00000018, 0x00000022, 0x0000002c,
+    0x70635f45, 0x74735f70, 0x5f656c79, 0x656e696c, 0x7269645f, 0x69746365,
-    0x00030003, 0x00000002, 0x000001c2, 0x000a0004,
+    0x00006576, 0x00080004, 0x475f4c47, 0x4c474f4f, 0x6e695f45, 0x64756c63,
-    0x475f4c47, 0x4c474f4f, 0x70635f45, 0x74735f70,
+    0x69645f65, 0x74636572, 0x00657669, 0x00040005, 0x00000004, 0x6e69616d,
-    0x5f656c79, 0x656e696c, 0x7269645f, 0x69746365,
+    0x00000000, 0x00050005, 0x0000000c, 0x69736f70, 0x6e6f6974, 0x00000073,
-    0x00006576, 0x00080004, 0x475f4c47, 0x4c474f4f,
+    0x00030005, 0x00000015, 0x00736f70, 0x00060005, 0x00000018, 0x565f6c67,
-    0x6e695f45, 0x64756c63, 0x69645f65, 0x74636572,
+    0x65747265, 0x646e4978, 0x00007865, 0x00060005, 0x00000020, 0x505f6c67,
-    0x00657669, 0x00040005, 0x00000004, 0x6e69616d,
+    0x65567265, 0x78657472, 0x00000000, 0x00060006, 0x00000020, 0x00000000,
-    0x00000000, 0x00050005, 0x0000000c, 0x69736f70,
+    0x505f6c67, 0x7469736f, 0x006e6f69, 0x00070006, 0x00000020, 0x00000001,
-    0x6e6f6974, 0x00000073, 0x00030005, 0x00000015,
+    0x505f6c67, 0x746e696f, 0x657a6953, 0x00000000, 0x00070006, 0x00000020,
-    0x00736f70, 0x00060005, 0x00000018, 0x565f6c67,
+    0x00000002, 0x435f6c67, 0x4470696c, 0x61747369, 0x0065636e, 0x00070006,
-    0x65747265, 0x646e4978, 0x00007865, 0x00060005,
+    0x00000020, 0x00000003, 0x435f6c67, 0x446c6c75, 0x61747369, 0x0065636e,
-    0x00000020, 0x505f6c67, 0x65567265, 0x78657472,
+    0x00030005, 0x00000022, 0x00000000, 0x00030005, 0x0000002c, 0x00007675,
-    0x00000000, 0x00060006, 0x00000020, 0x00000000,
+    0x00040047, 0x00000018, 0x0000000b, 0x0000002a, 0x00030047, 0x00000020,
-    0x505f6c67, 0x7469736f, 0x006e6f69, 0x00070006,
+    0x00000002, 0x00050048, 0x00000020, 0x00000000, 0x0000000b, 0x00000000,
-    0x00000020, 0x00000001, 0x505f6c67, 0x746e696f,
+    0x00050048, 0x00000020, 0x00000001, 0x0000000b, 0x00000001, 0x00050048,
-    0x657a6953, 0x00000000, 0x00070006, 0x00000020,
+    0x00000020, 0x00000002, 0x0000000b, 0x00000003, 0x00050048, 0x00000020,
-    0x00000002, 0x435f6c67, 0x4470696c, 0x61747369,
+    0x00000003, 0x0000000b, 0x00000004, 0x00040047, 0x0000002c, 0x0000001e,
-    0x0065636e, 0x00070006, 0x00000020, 0x00000003,
+    0x00000000, 0x00020013, 0x00000002, 0x00030021, 0x00000003, 0x00000002,
-    0x435f6c67, 0x446c6c75, 0x61747369, 0x0065636e,
+    0x00030016, 0x00000006, 0x00000020, 0x00040017, 0x00000007, 0x00000006,
-    0x00030005, 0x00000022, 0x00000000, 0x00030005,
+    0x00000002, 0x00040015, 0x00000008, 0x00000020, 0x00000000, 0x0004002b,
-    0x0000002c, 0x00007675, 0x00040047, 0x00000018,
+    0x00000008, 0x00000009, 0x00000006, 0x0004001c, 0x0000000a, 0x00000007,
-    0x0000000b, 0x0000002a, 0x00030047, 0x00000020,
+    0x00000009, 0x00040020, 0x0000000b, 0x00000006, 0x0000000a, 0x0004003b,
-    0x00000002, 0x00050048, 0x00000020, 0x00000000,
+    0x0000000b, 0x0000000c, 0x00000006, 0x0004002b, 0x00000006, 0x0000000d,
-    0x0000000b, 0x00000000, 0x00050048, 0x00000020,
+    0xbf800000, 0x0005002c, 0x00000007, 0x0000000e, 0x0000000d, 0x0000000d,
-    0x00000001, 0x0000000b, 0x00000001, 0x00050048,
+    0x0004002b, 0x00000006, 0x0000000f, 0x3f800000, 0x0005002c, 0x00000007,
-    0x00000020, 0x00000002, 0x0000000b, 0x00000003,
+    0x00000010, 0x0000000f, 0x0000000d, 0x0005002c, 0x00000007, 0x00000011,
-    0x00050048, 0x00000020, 0x00000003, 0x0000000b,
+    0x0000000d, 0x0000000f, 0x0005002c, 0x00000007, 0x00000012, 0x0000000f,
-    0x00000004, 0x00040047, 0x0000002c, 0x0000001e,
+    0x0000000f, 0x0009002c, 0x0000000a, 0x00000013, 0x0000000e, 0x00000010,
-    0x00000000, 0x00020013, 0x00000002, 0x00030021,
+    0x00000011, 0x00000011, 0x00000010, 0x00000012, 0x00040020, 0x00000014,
-    0x00000003, 0x00000002, 0x00030016, 0x00000006,
+    0x00000007, 0x00000007, 0x00040015, 0x00000016, 0x00000020, 0x00000001,
-    0x00000020, 0x00040017, 0x00000007, 0x00000006,
+    0x00040020, 0x00000017, 0x00000001, 0x00000016, 0x0004003b, 0x00000017,
-    0x00000002, 0x00040015, 0x00000008, 0x00000020,
+    0x00000018, 0x00000001, 0x00040020, 0x0000001a, 0x00000006, 0x00000007,
-    0x00000000, 0x0004002b, 0x00000008, 0x00000009,
+    0x00040017, 0x0000001d, 0x00000006, 0x00000004, 0x0004002b, 0x00000008,
-    0x00000006, 0x0004001c, 0x0000000a, 0x00000007,
+    0x0000001e, 0x00000001, 0x0004001c, 0x0000001f, 0x00000006, 0x0000001e,
-    0x00000009, 0x00040020, 0x0000000b, 0x00000006,
+    0x0006001e, 0x00000020, 0x0000001d, 0x00000006, 0x0000001f, 0x0000001f,
-    0x0000000a, 0x0004003b, 0x0000000b, 0x0000000c,
+    0x00040020, 0x00000021, 0x00000003, 0x00000020, 0x0004003b, 0x00000021,
-    0x00000006, 0x0004002b, 0x00000006, 0x0000000d,
+    0x00000022, 0x00000003, 0x0004002b, 0x00000016, 0x00000023, 0x00000000,
-    0xbf800000, 0x0005002c, 0x00000007, 0x0000000e,
+    0x0004002b, 0x00000006, 0x00000025, 0x00000000, 0x00040020, 0x00000029,
-    0x0000000d, 0x0000000d, 0x0004002b, 0x00000006,
+    0x00000003, 0x0000001d, 0x00040020, 0x0000002b, 0x00000003, 0x00000007,
-    0x0000000f, 0x3f800000, 0x0005002c, 0x00000007,
+    0x0004003b, 0x0000002b, 0x0000002c, 0x00000003, 0x0004002b, 0x00000006,
-    0x00000010, 0x0000000f, 0x0000000d, 0x0005002c,
+    0x0000002e, 0x3f000000, 0x00050036, 0x00000002, 0x00000004, 0x00000000,
-    0x00000007, 0x00000011, 0x0000000d, 0x0000000f,
+    0x00000003, 0x000200f8, 0x00000005, 0x0004003b, 0x00000014, 0x00000015,
-    0x0005002c, 0x00000007, 0x00000012, 0x0000000f,
+    0x00000007, 0x0003003e, 0x0000000c, 0x00000013, 0x0004003d, 0x00000016,
-    0x0000000f, 0x0009002c, 0x0000000a, 0x00000013,
+    0x00000019, 0x00000018, 0x00050041, 0x0000001a, 0x0000001b, 0x0000000c,
-    0x0000000e, 0x00000010, 0x00000011, 0x00000011,
+    0x00000019, 0x0004003d, 0x00000007, 0x0000001c, 0x0000001b, 0x0003003e,
-    0x00000010, 0x00000012, 0x00040020, 0x00000014,
+    0x00000015, 0x0000001c, 0x0004003d, 0x00000007, 0x00000024, 0x00000015,
-    0x00000007, 0x00000007, 0x00040015, 0x00000016,
+    0x00050051, 0x00000006, 0x00000026, 0x00000024, 0x00000000, 0x00050051,
-    0x00000020, 0x00000001, 0x00040020, 0x00000017,
+    0x00000006, 0x00000027, 0x00000024, 0x00000001, 0x00070050, 0x0000001d,
-    0x00000001, 0x00000016, 0x0004003b, 0x00000017,
+    0x00000028, 0x00000026, 0x00000027, 0x00000025, 0x0000000f, 0x00050041,
-    0x00000018, 0x00000001, 0x00040020, 0x0000001a,
+    0x00000029, 0x0000002a, 0x00000022, 0x00000023, 0x0003003e, 0x0000002a,
-    0x00000006, 0x00000007, 0x00040017, 0x0000001d,
+    0x00000028, 0x0004003d, 0x00000007, 0x0000002d, 0x00000015, 0x0005008e,
-    0x00000006, 0x00000004, 0x0004002b, 0x00000008,
+    0x00000007, 0x0000002f, 0x0000002d, 0x0000002e, 0x00050050, 0x00000007,
-    0x0000001e, 0x00000001, 0x0004001c, 0x0000001f,
+    0x00000030, 0x0000002e, 0x0000002e, 0x00050081, 0x00000007, 0x00000031,
-    0x00000006, 0x0000001e, 0x0006001e, 0x00000020,
+    0x0000002f, 0x00000030, 0x0003003e, 0x0000002c, 0x00000031, 0x000100fd,
-    0x0000001d, 0x00000006, 0x0000001f, 0x0000001f,
+    0x00010038,
-    0x00040020, 0x00000021, 0x00000003, 0x00000020,
-    0x0004003b, 0x00000021, 0x00000022, 0x00000003,
-    0x0004002b, 0x00000016, 0x00000023, 0x00000000,
-    0x0004002b, 0x00000006, 0x00000025, 0x00000000,
-    0x00040020, 0x00000029, 0x00000003, 0x0000001d,
-    0x00040020, 0x0000002b, 0x00000003, 0x00000007,
-    0x0004003b, 0x0000002b, 0x0000002c, 0x00000003,
-    0x0004002b, 0x00000006, 0x0000002e, 0x3f000000,
-    0x00050036, 0x00000002, 0x00000004, 0x00000000,
-    0x00000003, 0x000200f8, 0x00000005, 0x0004003b,
-    0x00000014, 0x00000015, 0x00000007, 0x0003003e,
-    0x0000000c, 0x00000013, 0x0004003d, 0x00000016,
-    0x00000019, 0x00000018, 0x00050041, 0x0000001a,
-    0x0000001b, 0x0000000c, 0x00000019, 0x0004003d,
-    0x00000007, 0x0000001c, 0x0000001b, 0x0003003e,
-    0x00000015, 0x0000001c, 0x0004003d, 0x00000007,
-    0x00000024, 0x00000015, 0x00050051, 0x00000006,
-    0x00000026, 0x00000024, 0x00000000, 0x00050051,
-    0x00000006, 0x00000027, 0x00000024, 0x00000001,
-    0x00070050, 0x0000001d, 0x00000028, 0x00000026,
-    0x00000027, 0x00000025, 0x0000000f, 0x00050041,
-    0x00000029, 0x0000002a, 0x00000022, 0x00000023,
-    0x0003003e, 0x0000002a, 0x00000028, 0x0004003d,
-    0x00000007, 0x0000002d, 0x00000015, 0x0005008e,
-    0x00000007, 0x0000002f, 0x0000002d, 0x0000002e,
-    0x00050050, 0x00000007, 0x00000030, 0x0000002e,
-    0x0000002e, 0x00050081, 0x00000007, 0x00000031,
-    0x0000002f, 0x00000030, 0x0003003e, 0x0000002c,
-    0x00000031, 0x000100fd, 0x00010038,
 };
 
 }  // namespace sophia::shaders

engine/src/shaders/mesh.frag

@@ -0,0 +1,9 @@
+#version 450
+
+layout (location = 0) in vec4 fragColor;
+
+layout (location = 0) out vec4 outColor;
+
+void main() {
+  outColor = vec4(fragColor.rgb, 1.0);
+}

engine/src/shaders/mesh.frag.spv.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <array>
+#include <cstdint>
+
+namespace sophia::shaders {
+
+inline constexpr std::array<uint32_t, 151> mesh_frag_spv = {
+    0x07230203, 0x00010000, 0x000d000b, 0x00000014, 0x00000000, 0x00020011,
+    0x00000001, 0x0006000b, 0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
+    0x00000000, 0x0003000e, 0x00000000, 0x00000001, 0x0007000f, 0x00000004,
+    0x00000004, 0x6e69616d, 0x00000000, 0x00000009, 0x0000000b, 0x00030010,
+    0x00000004, 0x00000007, 0x00030003, 0x00000002, 0x000001c2, 0x000a0004,
+    0x475f4c47, 0x4c474f4f, 0x70635f45, 0x74735f70, 0x5f656c79, 0x656e696c,
+    0x7269645f, 0x69746365, 0x00006576, 0x00080004, 0x475f4c47, 0x4c474f4f,
+    0x6e695f45, 0x64756c63, 0x69645f65, 0x74636572, 0x00657669, 0x00040005,
+    0x00000004, 0x6e69616d, 0x00000000, 0x00050005, 0x00000009, 0x4374756f,
+    0x726f6c6f, 0x00000000, 0x00050005, 0x0000000b, 0x67617266, 0x6f6c6f43,
+    0x00000072, 0x00040047, 0x00000009, 0x0000001e, 0x00000000, 0x00040047,
+    0x0000000b, 0x0000001e, 0x00000000, 0x00020013, 0x00000002, 0x00030021,
+    0x00000003, 0x00000002, 0x00030016, 0x00000006, 0x00000020, 0x00040017,
+    0x00000007, 0x00000006, 0x00000004, 0x00040020, 0x00000008, 0x00000003,
+    0x00000007, 0x0004003b, 0x00000008, 0x00000009, 0x00000003, 0x00040020,
+    0x0000000a, 0x00000001, 0x00000007, 0x0004003b, 0x0000000a, 0x0000000b,
+    0x00000001, 0x00040017, 0x0000000c, 0x00000006, 0x00000003, 0x0004002b,
+    0x00000006, 0x0000000f, 0x3f800000, 0x00050036, 0x00000002, 0x00000004,
+    0x00000000, 0x00000003, 0x000200f8, 0x00000005, 0x0004003d, 0x00000007,
+    0x0000000d, 0x0000000b, 0x0008004f, 0x0000000c, 0x0000000e, 0x0000000d,
+    0x0000000d, 0x00000000, 0x00000001, 0x00000002, 0x00050051, 0x00000006,
+    0x00000010, 0x0000000e, 0x00000000, 0x00050051, 0x00000006, 0x00000011,
+    0x0000000e, 0x00000001, 0x00050051, 0x00000006, 0x00000012, 0x0000000e,
+    0x00000002, 0x00070050, 0x00000007, 0x00000013, 0x00000010, 0x00000011,
+    0x00000012, 0x0000000f, 0x0003003e, 0x00000009, 0x00000013, 0x000100fd,
+    0x00010038,
+};
+
+}  // namespace sophia::shaders

engine/src/shaders/mesh.vert

@@ -0,0 +1,23 @@
+#version 450
+
+// Per vertex; layout must match MeshVertex. Normal and UV are unused until
+// there is lighting and texturing.
+layout (location = 0) in vec3 position;
+layout (location = 1) in vec3 normal;
+layout (location = 2) in vec2 uv;
+layout (location = 3) in vec4 color;
+
+// Per instance; layout must match MeshRenderSystem::Instance.
+layout (location = 4) in mat4 model;
+layout (location = 8) in vec4 instanceColor;
+
+layout (location = 0) out vec4 fragColor;
+
+layout (push_constant) uniform Push {
+  mat4 viewProjection;
+} push;
+
+void main() {
+  gl_Position = push.viewProjection * model * vec4(position, 1.0);
+  fragColor = color * instanceColor;
+}

engine/src/shaders/mesh.vert.spv.h

@@ -0,0 +1,80 @@
+#pragma once
+
+#include <array>
+#include <cstdint>
+
+namespace sophia::shaders {
+
+inline constexpr std::array<uint32_t, 411> mesh_vert_spv = {
+    0x07230203, 0x00010000, 0x000d000b, 0x00000032, 0x00000000, 0x00020011,
+    0x00000001, 0x0006000b, 0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
+    0x00000000, 0x0003000e, 0x00000000, 0x00000001, 0x000d000f, 0x00000000,
+    0x00000004, 0x6e69616d, 0x00000000, 0x0000000d, 0x00000018, 0x0000001d,
+    0x00000027, 0x00000029, 0x0000002b, 0x0000002e, 0x00000031, 0x00030003,
+    0x00000002, 0x000001c2, 0x000a0004, 0x475f4c47, 0x4c474f4f, 0x70635f45,
+    0x74735f70, 0x5f656c79, 0x656e696c, 0x7269645f, 0x69746365, 0x00006576,
+    0x00080004, 0x475f4c47, 0x4c474f4f, 0x6e695f45, 0x64756c63, 0x69645f65,
+    0x74636572, 0x00657669, 0x00040005, 0x00000004, 0x6e69616d, 0x00000000,
+    0x00060005, 0x0000000b, 0x505f6c67, 0x65567265, 0x78657472, 0x00000000,
+    0x00060006, 0x0000000b, 0x00000000, 0x505f6c67, 0x7469736f, 0x006e6f69,
+    0x00070006, 0x0000000b, 0x00000001, 0x505f6c67, 0x746e696f, 0x657a6953,
+    0x00000000, 0x00070006, 0x0000000b, 0x00000002, 0x435f6c67, 0x4470696c,
+    0x61747369, 0x0065636e, 0x00070006, 0x0000000b, 0x00000003, 0x435f6c67,
+    0x446c6c75, 0x61747369, 0x0065636e, 0x00030005, 0x0000000d, 0x00000000,
+    0x00040005, 0x00000011, 0x68737550, 0x00000000, 0x00070006, 0x00000011,
+    0x00000000, 0x77656976, 0x6a6f7250, 0x69746365, 0x00006e6f, 0x00040005,
+    0x00000013, 0x68737570, 0x00000000, 0x00040005, 0x00000018, 0x65646f6d,
+    0x0000006c, 0x00050005, 0x0000001d, 0x69736f70, 0x6e6f6974, 0x00000000,
+    0x00050005, 0x00000027, 0x67617266, 0x6f6c6f43, 0x00000072, 0x00040005,
+    0x00000029, 0x6f6c6f63, 0x00000072, 0x00060005, 0x0000002b, 0x74736e69,
+    0x65636e61, 0x6f6c6f43, 0x00000072, 0x00040005, 0x0000002e, 0x6d726f6e,
+    0x00006c61, 0x00030005, 0x00000031, 0x00007675, 0x00030047, 0x0000000b,
+    0x00000002, 0x00050048, 0x0000000b, 0x00000000, 0x0000000b, 0x00000000,
+    0x00050048, 0x0000000b, 0x00000001, 0x0000000b, 0x00000001, 0x00050048,
+    0x0000000b, 0x00000002, 0x0000000b, 0x00000003, 0x00050048, 0x0000000b,
+    0x00000003, 0x0000000b, 0x00000004, 0x00030047, 0x00000011, 0x00000002,
+    0x00040048, 0x00000011, 0x00000000, 0x00000005, 0x00050048, 0x00000011,
+    0x00000000, 0x00000007, 0x00000010, 0x00050048, 0x00000011, 0x00000000,
+    0x00000023, 0x00000000, 0x00040047, 0x00000018, 0x0000001e, 0x00000004,
+    0x00040047, 0x0000001d, 0x0000001e, 0x00000000, 0x00040047, 0x00000027,
+    0x0000001e, 0x00000000, 0x00040047, 0x00000029, 0x0000001e, 0x00000003,
+    0x00040047, 0x0000002b, 0x0000001e, 0x00000008, 0x00040047, 0x0000002e,
+    0x0000001e, 0x00000001, 0x00040047, 0x00000031, 0x0000001e, 0x00000002,
+    0x00020013, 0x00000002, 0x00030021, 0x00000003, 0x00000002, 0x00030016,
+    0x00000006, 0x00000020, 0x00040017, 0x00000007, 0x00000006, 0x00000004,
+    0x00040015, 0x00000008, 0x00000020, 0x00000000, 0x0004002b, 0x00000008,
+    0x00000009, 0x00000001, 0x0004001c, 0x0000000a, 0x00000006, 0x00000009,
+    0x0006001e, 0x0000000b, 0x00000007, 0x00000006, 0x0000000a, 0x0000000a,
+    0x00040020, 0x0000000c, 0x00000003, 0x0000000b, 0x0004003b, 0x0000000c,
+    0x0000000d, 0x00000003, 0x00040015, 0x0000000e, 0x00000020, 0x00000001,
+    0x0004002b, 0x0000000e, 0x0000000f, 0x00000000, 0x00040018, 0x00000010,
+    0x00000007, 0x00000004, 0x0003001e, 0x00000011, 0x00000010, 0x00040020,
+    0x00000012, 0x00000009, 0x00000011, 0x0004003b, 0x00000012, 0x00000013,
+    0x00000009, 0x00040020, 0x00000014, 0x00000009, 0x00000010, 0x00040020,
+    0x00000017, 0x00000001, 0x00000010, 0x0004003b, 0x00000017, 0x00000018,
+    0x00000001, 0x00040017, 0x0000001b, 0x00000006, 0x00000003, 0x00040020,
+    0x0000001c, 0x00000001, 0x0000001b, 0x0004003b, 0x0000001c, 0x0000001d,
+    0x00000001, 0x0004002b, 0x00000006, 0x0000001f, 0x3f800000, 0x00040020,
+    0x00000025, 0x00000003, 0x00000007, 0x0004003b, 0x00000025, 0x00000027,
+    0x00000003, 0x00040020, 0x00000028, 0x00000001, 0x00000007, 0x0004003b,
+    0x00000028, 0x00000029, 0x00000001, 0x0004003b, 0x00000028, 0x0000002b,
+    0x00000001, 0x0004003b, 0x0000001c, 0x0000002e, 0x00000001, 0x00040017,
+    0x0000002f, 0x00000006, 0x00000002, 0x00040020, 0x00000030, 0x00000001,
+    0x0000002f, 0x0004003b, 0x00000030, 0x00000031, 0x00000001, 0x00050036,
+    0x00000002, 0x00000004, 0x00000000, 0x00000003, 0x000200f8, 0x00000005,
+    0x00050041, 0x00000014, 0x00000015, 0x00000013, 0x0000000f, 0x0004003d,
+    0x00000010, 0x00000016, 0x00000015, 0x0004003d, 0x00000010, 0x00000019,
+    0x00000018, 0x00050092, 0x00000010, 0x0000001a, 0x00000016, 0x00000019,
+    0x0004003d, 0x0000001b, 0x0000001e, 0x0000001d, 0x00050051, 0x00000006,
+    0x00000020, 0x0000001e, 0x00000000, 0x00050051, 0x00000006, 0x00000021,
+    0x0000001e, 0x00000001, 0x00050051, 0x00000006, 0x00000022, 0x0000001e,
+    0x00000002, 0x00070050, 0x00000007, 0x00000023, 0x00000020, 0x00000021,
+    0x00000022, 0x0000001f, 0x00050091, 0x00000007, 0x00000024, 0x0000001a,
+    0x00000023, 0x00050041, 0x00000025, 0x00000026, 0x0000000d, 0x0000000f,
+    0x0003003e, 0x00000026, 0x00000024, 0x0004003d, 0x00000007, 0x0000002a,
+    0x00000029, 0x0004003d, 0x00000007, 0x0000002c, 0x0000002b, 0x00050085,
+    0x00000007, 0x0000002d, 0x0000002a, 0x0000002c, 0x0003003e, 0x00000027,
+    0x0000002d, 0x000100fd, 0x00010038,
+};
+
+}  // namespace sophia::shaders

engine/src/shaders/model_render_system.frag

@@ -1,9 +1,9 @@
 #version 450
 
-layout (location = 0) in vec3 fragColor;
+layout (location = 0) in vec4 fragColor;
 
 layout (location = 0) out vec4 outColor;
 
 void main() {
-  outColor = vec4(fragColor, 1.0);
+  outColor = fragColor;
 }

engine/src/shaders/model_render_system.frag.spv.h

@@ -5,31 +5,36 @@
 
 namespace sophia::shaders {
 
-inline constexpr std::array<uint32_t, 143> model_render_system_frag_spv = {
+inline constexpr std::array<uint32_t, 113> model_render_system_frag_spv = {
-    0x07230203, 0x00010000, 0x000d000b, 0x00000013, 0x00000000, 0x00020011,
+    0x07230203, 0x00010000, 0x000d000b, 0x0000000d,
-    0x00000001, 0x0006000b, 0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
+    0x00000000, 0x00020011, 0x00000001, 0x0006000b,
-    0x00000000, 0x0003000e, 0x00000000, 0x00000001, 0x0007000f, 0x00000004,
+    0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
-    0x00000004, 0x6e69616d, 0x00000000, 0x00000009, 0x0000000c, 0x00030010,
+    0x00000000, 0x0003000e, 0x00000000, 0x00000001,
-    0x00000004, 0x00000007, 0x00030003, 0x00000002, 0x000001c2, 0x000a0004,
+    0x0007000f, 0x00000004, 0x00000004, 0x6e69616d,
-    0x475f4c47, 0x4c474f4f, 0x70635f45, 0x74735f70, 0x5f656c79, 0x656e696c,
+    0x00000000, 0x00000009, 0x0000000b, 0x00030010,
-    0x7269645f, 0x69746365, 0x00006576, 0x00080004, 0x475f4c47, 0x4c474f4f,
+    0x00000004, 0x00000007, 0x00030003, 0x00000002,
-    0x6e695f45, 0x64756c63, 0x69645f65, 0x74636572, 0x00657669, 0x00040005,
+    0x000001c2, 0x000a0004, 0x475f4c47, 0x4c474f4f,
-    0x00000004, 0x6e69616d, 0x00000000, 0x00050005, 0x00000009, 0x4374756f,
+    0x70635f45, 0x74735f70, 0x5f656c79, 0x656e696c,
-    0x726f6c6f, 0x00000000, 0x00050005, 0x0000000c, 0x67617266, 0x6f6c6f43,
+    0x7269645f, 0x69746365, 0x00006576, 0x00080004,
-    0x00000072, 0x00040047, 0x00000009, 0x0000001e, 0x00000000, 0x00040047,
+    0x475f4c47, 0x4c474f4f, 0x6e695f45, 0x64756c63,
-    0x0000000c, 0x0000001e, 0x00000000, 0x00020013, 0x00000002, 0x00030021,
+    0x69645f65, 0x74636572, 0x00657669, 0x00040005,
-    0x00000003, 0x00000002, 0x00030016, 0x00000006, 0x00000020, 0x00040017,
+    0x00000004, 0x6e69616d, 0x00000000, 0x00050005,
-    0x00000007, 0x00000006, 0x00000004, 0x00040020, 0x00000008, 0x00000003,
+    0x00000009, 0x4374756f, 0x726f6c6f, 0x00000000,
-    0x00000007, 0x0004003b, 0x00000008, 0x00000009, 0x00000003, 0x00040017,
+    0x00050005, 0x0000000b, 0x67617266, 0x6f6c6f43,
-    0x0000000a, 0x00000006, 0x00000003, 0x00040020, 0x0000000b, 0x00000001,
+    0x00000072, 0x00040047, 0x00000009, 0x0000001e,
-    0x0000000a, 0x0004003b, 0x0000000b, 0x0000000c, 0x00000001, 0x0004002b,
+    0x00000000, 0x00040047, 0x0000000b, 0x0000001e,
-    0x00000006, 0x0000000e, 0x3f800000, 0x00050036, 0x00000002, 0x00000004,
+    0x00000000, 0x00020013, 0x00000002, 0x00030021,
-    0x00000000, 0x00000003, 0x000200f8, 0x00000005, 0x0004003d, 0x0000000a,
+    0x00000003, 0x00000002, 0x00030016, 0x00000006,
-    0x0000000d, 0x0000000c, 0x00050051, 0x00000006, 0x0000000f, 0x0000000d,
+    0x00000020, 0x00040017, 0x00000007, 0x00000006,
-    0x00000000, 0x00050051, 0x00000006, 0x00000010, 0x0000000d, 0x00000001,
+    0x00000004, 0x00040020, 0x00000008, 0x00000003,
-    0x00050051, 0x00000006, 0x00000011, 0x0000000d, 0x00000002, 0x00070050,
+    0x00000007, 0x0004003b, 0x00000008, 0x00000009,
-    0x00000007, 0x00000012, 0x0000000f, 0x00000010, 0x00000011, 0x0000000e,
+    0x00000003, 0x00040020, 0x0000000a, 0x00000001,
-    0x0003003e, 0x00000009, 0x00000012, 0x000100fd, 0x00010038,
+    0x00000007, 0x0004003b, 0x0000000a, 0x0000000b,
+    0x00000001, 0x00050036, 0x00000002, 0x00000004,
+    0x00000000, 0x00000003, 0x000200f8, 0x00000005,
+    0x0004003d, 0x00000007, 0x0000000c, 0x0000000b,
+    0x0003003e, 0x00000009, 0x0000000c, 0x000100fd,
+    0x00010038,
 };
 
 }  // namespace sophia::shaders

engine/src/shaders/model_render_system.vert

@@ -1,9 +1,10 @@
 #version 450
 
-layout (location = 0) in vec2 position;
+// Per vertex; locations match Mesh::getAttributeDescriptions().
-layout (location = 1) in vec3 color;
+layout (location = 0) in vec3 position;
+layout (location = 3) in vec4 color;
 
-layout (location = 0) out vec3 fragColor;
+layout (location = 0) out vec4 fragColor;
 
 layout (push_constant) uniform Push {
   mat4 transform;
@@ -11,6 +12,6 @@ layout (push_constant) uniform Push {
 } push;
 
 void main() {
-  gl_Position = vec4(push.transform * vec4(position, 0.0, 1.0));
+  gl_Position = push.transform * vec4(position, 1.0);
   fragColor = color;
 }

engine/src/shaders/model_render_system.vert.spv.h

@@ -5,12 +5,12 @@
 
 namespace sophia::shaders {
 
-inline constexpr std::array<uint32_t, 345> model_render_system_vert_spv = {
+inline constexpr std::array<uint32_t, 338> model_render_system_vert_spv = {
-    0x07230203, 0x00010000, 0x000d000b, 0x00000029, 0x00000000, 0x00020011,
+    0x07230203, 0x00010000, 0x000d000b, 0x00000027, 0x00000000, 0x00020011,
     0x00000001, 0x0006000b, 0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
     0x00000000, 0x0003000e, 0x00000000, 0x00000001, 0x0009000f, 0x00000000,
-    0x00000004, 0x6e69616d, 0x00000000, 0x0000000d, 0x00000019, 0x00000025,
+    0x00000004, 0x6e69616d, 0x00000000, 0x0000000d, 0x00000019, 0x00000023,
-    0x00000027, 0x00030003, 0x00000002, 0x000001c2, 0x000a0004, 0x475f4c47,
+    0x00000025, 0x00030003, 0x00000002, 0x000001c2, 0x000a0004, 0x475f4c47,
     0x4c474f4f, 0x70635f45, 0x74735f70, 0x5f656c79, 0x656e696c, 0x7269645f,
     0x69746365, 0x00006576, 0x00080004, 0x475f4c47, 0x4c474f4f, 0x6e695f45,
     0x64756c63, 0x69645f65, 0x74636572, 0x00657669, 0x00040005, 0x00000004,
@@ -24,8 +24,8 @@ inline constexpr std::array<uint32_t, 345> model_render_system_vert_spv = {
     0x00060006, 0x00000011, 0x00000000, 0x6e617274, 0x726f6673, 0x0000006d,
     0x00050006, 0x00000011, 0x00000001, 0x6f6c6f63, 0x00000072, 0x00040005,
     0x00000013, 0x68737570, 0x00000000, 0x00050005, 0x00000019, 0x69736f70,
-    0x6e6f6974, 0x00000000, 0x00050005, 0x00000025, 0x67617266, 0x6f6c6f43,
+    0x6e6f6974, 0x00000000, 0x00050005, 0x00000023, 0x67617266, 0x6f6c6f43,
-    0x00000072, 0x00040005, 0x00000027, 0x6f6c6f63, 0x00000072, 0x00030047,
+    0x00000072, 0x00040005, 0x00000025, 0x6f6c6f63, 0x00000072, 0x00030047,
     0x0000000b, 0x00000002, 0x00050048, 0x0000000b, 0x00000000, 0x0000000b,
     0x00000000, 0x00050048, 0x0000000b, 0x00000001, 0x0000000b, 0x00000001,
     0x00050048, 0x0000000b, 0x00000002, 0x0000000b, 0x00000003, 0x00050048,
@@ -34,8 +34,8 @@ inline constexpr std::array<uint32_t, 345> model_render_system_vert_spv = {
     0x00000011, 0x00000000, 0x00000007, 0x00000010, 0x00050048, 0x00000011,
     0x00000000, 0x00000023, 0x00000000, 0x00050048, 0x00000011, 0x00000001,
     0x00000023, 0x00000040, 0x00040047, 0x00000019, 0x0000001e, 0x00000000,
-    0x00040047, 0x00000025, 0x0000001e, 0x00000000, 0x00040047, 0x00000027,
+    0x00040047, 0x00000023, 0x0000001e, 0x00000000, 0x00040047, 0x00000025,
-    0x0000001e, 0x00000001, 0x00020013, 0x00000002, 0x00030021, 0x00000003,
+    0x0000001e, 0x00000003, 0x00020013, 0x00000002, 0x00030021, 0x00000003,
     0x00000002, 0x00030016, 0x00000006, 0x00000020, 0x00040017, 0x00000007,
     0x00000006, 0x00000004, 0x00040015, 0x00000008, 0x00000020, 0x00000000,
     0x0004002b, 0x00000008, 0x00000009, 0x00000001, 0x0004001c, 0x0000000a,
@@ -46,24 +46,23 @@ inline constexpr std::array<uint32_t, 345> model_render_system_vert_spv = {
     0x00040018, 0x00000010, 0x00000007, 0x00000004, 0x0004001e, 0x00000011,
     0x00000010, 0x00000007, 0x00040020, 0x00000012, 0x00000009, 0x00000011,
     0x0004003b, 0x00000012, 0x00000013, 0x00000009, 0x00040020, 0x00000014,
-    0x00000009, 0x00000010, 0x00040017, 0x00000017, 0x00000006, 0x00000002,
+    0x00000009, 0x00000010, 0x00040017, 0x00000017, 0x00000006, 0x00000003,
     0x00040020, 0x00000018, 0x00000001, 0x00000017, 0x0004003b, 0x00000018,
-    0x00000019, 0x00000001, 0x0004002b, 0x00000006, 0x0000001b, 0x00000000,
+    0x00000019, 0x00000001, 0x0004002b, 0x00000006, 0x0000001b, 0x3f800000,
-    0x0004002b, 0x00000006, 0x0000001c, 0x3f800000, 0x00040020, 0x00000021,
+    0x00040020, 0x00000021, 0x00000003, 0x00000007, 0x0004003b, 0x00000021,
-    0x00000003, 0x00000007, 0x00040017, 0x00000023, 0x00000006, 0x00000003,
+    0x00000023, 0x00000003, 0x00040020, 0x00000024, 0x00000001, 0x00000007,
-    0x00040020, 0x00000024, 0x00000003, 0x00000023, 0x0004003b, 0x00000024,
+    0x0004003b, 0x00000024, 0x00000025, 0x00000001, 0x00050036, 0x00000002,
-    0x00000025, 0x00000003, 0x00040020, 0x00000026, 0x00000001, 0x00000023,
-    0x0004003b, 0x00000026, 0x00000027, 0x00000001, 0x00050036, 0x00000002,
     0x00000004, 0x00000000, 0x00000003, 0x000200f8, 0x00000005, 0x00050041,
     0x00000014, 0x00000015, 0x00000013, 0x0000000f, 0x0004003d, 0x00000010,
     0x00000016, 0x00000015, 0x0004003d, 0x00000017, 0x0000001a, 0x00000019,
-    0x00050051, 0x00000006, 0x0000001d, 0x0000001a, 0x00000000, 0x00050051,
+    0x00050051, 0x00000006, 0x0000001c, 0x0000001a, 0x00000000, 0x00050051,
-    0x00000006, 0x0000001e, 0x0000001a, 0x00000001, 0x00070050, 0x00000007,
+    0x00000006, 0x0000001d, 0x0000001a, 0x00000001, 0x00050051, 0x00000006,
-    0x0000001f, 0x0000001d, 0x0000001e, 0x0000001b, 0x0000001c, 0x00050091,
+    0x0000001e, 0x0000001a, 0x00000002, 0x00070050, 0x00000007, 0x0000001f,
-    0x00000007, 0x00000020, 0x00000016, 0x0000001f, 0x00050041, 0x00000021,
+    0x0000001c, 0x0000001d, 0x0000001e, 0x0000001b, 0x00050091, 0x00000007,
-    0x00000022, 0x0000000d, 0x0000000f, 0x0003003e, 0x00000022, 0x00000020,
+    0x00000020, 0x00000016, 0x0000001f, 0x00050041, 0x00000021, 0x00000022,
-    0x0004003d, 0x00000023, 0x00000028, 0x00000027, 0x0003003e, 0x00000025,
+    0x0000000d, 0x0000000f, 0x0003003e, 0x00000022, 0x00000020, 0x0004003d,
-    0x00000028, 0x000100fd, 0x00010038,
+    0x00000007, 0x00000026, 0x00000025, 0x0003003e, 0x00000023, 0x00000026,
+    0x000100fd, 0x00010038,
 };
 
 }  // namespace sophia::shaders

engine/src/shaders/sprite.vert

@@ -22,10 +22,8 @@ void main() {
   vec2 corner = CORNERS[gl_VertexIndex];
 
   gl_Position = push.viewProjection * model * vec4(corner, 0.0, 1.0);
-  // Draw order comes from the CPU-side sort, so flatten depth; sprites should
-  // never be clipped by the camera's near/far planes.
-  gl_Position.z = 0.0;
 
   fragColor = color;
-  fragUv = mix(uvRect.xy, uvRect.zw, corner);
+  // The quad's y runs up and the texture's v runs down.
+  fragUv = mix(uvRect.xy, uvRect.zw, vec2(corner.x, 1.0 - corner.y));
 }

engine/src/shaders/sprite.vert.spv.h

@@ -5,12 +5,12 @@
 
 namespace sophia::shaders {
 
-inline constexpr std::array<uint32_t, 519> sprite_vert_spv = {
+inline constexpr std::array<uint32_t, 534> sprite_vert_spv = {
-    0x07230203, 0x00010000, 0x000d000b, 0x00000045, 0x00000000, 0x00020011,
+    0x07230203, 0x00010000, 0x000d000b, 0x00000049, 0x00000000, 0x00020011,
     0x00000001, 0x0006000b, 0x00000001, 0x4c534c47, 0x6474732e, 0x3035342e,
     0x00000000, 0x0003000e, 0x00000000, 0x00000001, 0x000c000f, 0x00000000,
     0x00000004, 0x6e69616d, 0x00000000, 0x00000016, 0x00000021, 0x0000002b,
-    0x00000038, 0x0000003a, 0x0000003d, 0x0000003e, 0x00030003, 0x00000002,
+    0x00000035, 0x00000037, 0x0000003a, 0x0000003b, 0x00030003, 0x00000002,
     0x000001c2, 0x000a0004, 0x475f4c47, 0x4c474f4f, 0x70635f45, 0x74735f70,
     0x5f656c79, 0x656e696c, 0x7269645f, 0x69746365, 0x00006576, 0x00080004,
     0x475f4c47, 0x4c474f4f, 0x6e695f45, 0x64756c63, 0x69645f65, 0x74636572,
@@ -26,9 +26,9 @@ inline constexpr std::array<uint32_t, 519> sprite_vert_spv = {
     0x00000021, 0x00000000, 0x00040005, 0x00000024, 0x68737550, 0x00000000,
     0x00070006, 0x00000024, 0x00000000, 0x77656976, 0x6a6f7250, 0x69746365,
     0x00006e6f, 0x00040005, 0x00000026, 0x68737570, 0x00000000, 0x00040005,
-    0x0000002b, 0x65646f6d, 0x0000006c, 0x00050005, 0x00000038, 0x67617266,
+    0x0000002b, 0x65646f6d, 0x0000006c, 0x00050005, 0x00000035, 0x67617266,
-    0x6f6c6f43, 0x00000072, 0x00040005, 0x0000003a, 0x6f6c6f63, 0x00000072,
+    0x6f6c6f43, 0x00000072, 0x00040005, 0x00000037, 0x6f6c6f63, 0x00000072,
-    0x00040005, 0x0000003d, 0x67617266, 0x00007655, 0x00040005, 0x0000003e,
+    0x00040005, 0x0000003a, 0x67617266, 0x00007655, 0x00040005, 0x0000003b,
     0x65527675, 0x00007463, 0x00040047, 0x00000016, 0x0000000b, 0x0000002a,
     0x00030047, 0x0000001f, 0x00000002, 0x00050048, 0x0000001f, 0x00000000,
     0x0000000b, 0x00000000, 0x00050048, 0x0000001f, 0x00000001, 0x0000000b,
@@ -37,9 +37,9 @@ inline constexpr std::array<uint32_t, 519> sprite_vert_spv = {
     0x00000024, 0x00000002, 0x00040048, 0x00000024, 0x00000000, 0x00000005,
     0x00050048, 0x00000024, 0x00000000, 0x00000007, 0x00000010, 0x00050048,
     0x00000024, 0x00000000, 0x00000023, 0x00000000, 0x00040047, 0x0000002b,
-    0x0000001e, 0x00000000, 0x00040047, 0x00000038, 0x0000001e, 0x00000000,
+    0x0000001e, 0x00000000, 0x00040047, 0x00000035, 0x0000001e, 0x00000000,
-    0x00040047, 0x0000003a, 0x0000001e, 0x00000004, 0x00040047, 0x0000003d,
+    0x00040047, 0x00000037, 0x0000001e, 0x00000004, 0x00040047, 0x0000003a,
-    0x0000001e, 0x00000001, 0x00040047, 0x0000003e, 0x0000001e, 0x00000005,
+    0x0000001e, 0x00000001, 0x00040047, 0x0000003b, 0x0000001e, 0x00000005,
     0x00020013, 0x00000002, 0x00030021, 0x00000003, 0x00000002, 0x00030016,
     0x00000006, 0x00000020, 0x00040017, 0x00000007, 0x00000006, 0x00000002,
     0x00040020, 0x00000008, 0x00000007, 0x00000007, 0x00040015, 0x0000000a,
@@ -63,12 +63,12 @@ inline constexpr std::array<uint32_t, 519> sprite_vert_spv = {
     0x00000009, 0x00000024, 0x0004003b, 0x00000025, 0x00000026, 0x00000009,
     0x00040020, 0x00000027, 0x00000009, 0x00000023, 0x00040020, 0x0000002a,
     0x00000001, 0x00000023, 0x0004003b, 0x0000002a, 0x0000002b, 0x00000001,
-    0x00040020, 0x00000033, 0x00000003, 0x0000001c, 0x0004002b, 0x0000000a,
+    0x00040020, 0x00000033, 0x00000003, 0x0000001c, 0x0004003b, 0x00000033,
-    0x00000035, 0x00000002, 0x00040020, 0x00000036, 0x00000003, 0x00000006,
+    0x00000035, 0x00000003, 0x00040020, 0x00000036, 0x00000001, 0x0000001c,
-    0x0004003b, 0x00000033, 0x00000038, 0x00000003, 0x00040020, 0x00000039,
+    0x0004003b, 0x00000036, 0x00000037, 0x00000001, 0x00040020, 0x00000039,
-    0x00000001, 0x0000001c, 0x0004003b, 0x00000039, 0x0000003a, 0x00000001,
+    0x00000003, 0x00000007, 0x0004003b, 0x00000039, 0x0000003a, 0x00000003,
-    0x00040020, 0x0000003c, 0x00000003, 0x00000007, 0x0004003b, 0x0000003c,
+    0x0004003b, 0x00000036, 0x0000003b, 0x00000001, 0x0004002b, 0x0000000a,
-    0x0000003d, 0x00000003, 0x0004003b, 0x00000039, 0x0000003e, 0x00000001,
+    0x00000040, 0x00000000, 0x00040020, 0x00000041, 0x00000007, 0x00000006,
     0x00050036, 0x00000002, 0x00000004, 0x00000000, 0x00000003, 0x000200f8,
     0x00000005, 0x0004003b, 0x00000008, 0x00000009, 0x00000007, 0x0004003b,
     0x00000018, 0x00000019, 0x00000007, 0x0004003d, 0x00000014, 0x00000017,
@@ -83,16 +83,18 @@ inline constexpr std::array<uint32_t, 519> sprite_vert_spv = {
     0x00070050, 0x0000001c, 0x00000031, 0x0000002f, 0x00000030, 0x0000000d,
     0x0000000f, 0x00050091, 0x0000001c, 0x00000032, 0x0000002d, 0x00000031,
     0x00050041, 0x00000033, 0x00000034, 0x00000021, 0x00000022, 0x0003003e,
-    0x00000034, 0x00000032, 0x00060041, 0x00000036, 0x00000037, 0x00000021,
+    0x00000034, 0x00000032, 0x0004003d, 0x0000001c, 0x00000038, 0x00000037,
-    0x00000022, 0x00000035, 0x0003003e, 0x00000037, 0x0000000d, 0x0004003d,
+    0x0003003e, 0x00000035, 0x00000038, 0x0004003d, 0x0000001c, 0x0000003c,
-    0x0000001c, 0x0000003b, 0x0000003a, 0x0003003e, 0x00000038, 0x0000003b,
+    0x0000003b, 0x0007004f, 0x00000007, 0x0000003d, 0x0000003c, 0x0000003c,
-    0x0004003d, 0x0000001c, 0x0000003f, 0x0000003e, 0x0007004f, 0x00000007,
+    0x00000000, 0x00000001, 0x0004003d, 0x0000001c, 0x0000003e, 0x0000003b,
-    0x00000040, 0x0000003f, 0x0000003f, 0x00000000, 0x00000001, 0x0004003d,
+    0x0007004f, 0x00000007, 0x0000003f, 0x0000003e, 0x0000003e, 0x00000002,
-    0x0000001c, 0x00000041, 0x0000003e, 0x0007004f, 0x00000007, 0x00000042,
+    0x00000003, 0x00050041, 0x00000041, 0x00000042, 0x00000009, 0x00000040,
-    0x00000041, 0x00000041, 0x00000002, 0x00000003, 0x0004003d, 0x00000007,
+    0x0004003d, 0x00000006, 0x00000043, 0x00000042, 0x00050041, 0x00000041,
-    0x00000043, 0x00000009, 0x0008000c, 0x00000007, 0x00000044, 0x00000001,
+    0x00000044, 0x00000009, 0x0000001d, 0x0004003d, 0x00000006, 0x00000045,
-    0x0000002e, 0x00000040, 0x00000042, 0x00000043, 0x0003003e, 0x0000003d,
+    0x00000044, 0x00050083, 0x00000006, 0x00000046, 0x0000000f, 0x00000045,
-    0x00000044, 0x000100fd, 0x00010038,
+    0x00050050, 0x00000007, 0x00000047, 0x00000043, 0x00000046, 0x0008000c,
+    0x00000007, 0x00000048, 0x00000001, 0x0000002e, 0x0000003d, 0x0000003f,
+    0x00000047, 0x0003003e, 0x0000003a, 0x00000048, 0x000100fd, 0x00010038,
 };
 
 }  // namespace sophia::shaders

engine/src/ui/panel.cpp

@@ -47,8 +47,9 @@ void Panel::draw(const FrameInfo& frameInfo) {
   }
 
   bool open = true;
-  ImGui::Begin(config.name.c_str(), config.hasCloseButton() ? &open : nullptr,
+  this->shown = ImGui::Begin(config.name.c_str(),
-               config.getWindowFlags());
+                             config.hasCloseButton() ? &open : nullptr,
+                             config.getWindowFlags());
   onUpdate(frameInfo);
   ImGui::End();
 

engine/src/vulkan/device.hpp

@@ -48,6 +48,7 @@ class Device {
 
   void waitIdle() { this->device->waitIdle(); }
 
+  vk::PhysicalDevice getPhysicalDevice() const { return this->physicalDevice; }
   VmaAllocator getAllocator() const { return this->allocator; }
   vk::CommandPool getCommandPool() const { return this->commandPool; }
   vk::SurfaceKHR getSurface() const { return surface; }

engine/src/vulkan/pipelines/graphics_pipeline.cpp

@@ -101,6 +101,21 @@ GraphicsPipeline::Builder& GraphicsPipeline::Builder::setAlphaBlending(
   return *this;
 }
 
+GraphicsPipeline::Builder& GraphicsPipeline::Builder::setDepthTest(
+    bool test, bool write, vk::CompareOp compareOp) {
+  this->depthTest = test;
+  this->depthWrite = write;
+  this->depthCompareOp = compareOp;
+  return *this;
+}
+
+GraphicsPipeline::Builder& GraphicsPipeline::Builder::setCullMode(
+    vk::CullModeFlags cullMode, vk::FrontFace frontFace) {
+  this->cullMode = cullMode;
+  this->frontFace = frontFace;
+  return *this;
+}
+
 std::unique_ptr<GraphicsPipeline> GraphicsPipeline::Builder::build() const {
   if (this->vertexShader == nullptr || this->fragmentShader == nullptr) {
     log::fatal(
@@ -130,26 +145,14 @@ std::unique_ptr<GraphicsPipeline> GraphicsPipeline::Builder::build() const {
         "setDepthAttachmentFormat() was not called");
   }
 
-  return std::unique_ptr<GraphicsPipeline>(new GraphicsPipeline(
+  return std::unique_ptr<GraphicsPipeline>(new GraphicsPipeline(*this));
-      this->device, *this->vertexShader, *this->fragmentShader,
-      this->pipelineLayout, this->colorAttachmentFormats,
-      this->depthAttachmentFormat, this->stencilAttachmentFormat,
-      this->bindingDescriptions, this->attributeDescriptions,
-      this->alphaBlending));
 }
 
-GraphicsPipeline::GraphicsPipeline(
+GraphicsPipeline::GraphicsPipeline(const Builder& builder)
-    Device& device, Shader& vertexShader, Shader& fragmentShader,
+    : Pipeline(builder.device, vk::PipelineBindPoint::eGraphics) {
-    vk::PipelineLayout pipelineLayout,
-    std::vector<vk::Format> colorAttachmentFormats,
-    vk::Format depthAttachmentFormat, vk::Format stencilAttachmentFormat,
-    std::vector<vk::VertexInputBindingDescription> bindingDescriptions,
-    std::vector<vk::VertexInputAttributeDescription> attributeDescriptions,
-    bool alphaBlending)
-    : Pipeline(device, vk::PipelineBindPoint::eGraphics) {
   setDefaultGraphicsPipelineConfig();
 
-  if (alphaBlending) {
+  if (builder.alphaBlending) {
     vk::PipelineColorBlendAttachmentState& blend =
         this->config.colorBlendAttachment;
     blend.blendEnable = vk::True;
@@ -159,17 +162,24 @@ GraphicsPipeline::GraphicsPipeline(
     blend.dstAlphaBlendFactor = vk::BlendFactor::eOneMinusSrcAlpha;
   }
 
-  this->config.bindingDescriptions = std::move(bindingDescriptions);
+  this->config.depthStencilInfo.depthTestEnable = builder.depthTest;
-  this->config.attributeDescriptions = std::move(attributeDescriptions);
+  this->config.depthStencilInfo.depthWriteEnable = builder.depthWrite;
-  this->config.pipelineLayout = pipelineLayout;
+  this->config.depthStencilInfo.depthCompareOp = builder.depthCompareOp;
-  this->config.colorAttachmentFormats = std::move(colorAttachmentFormats);
+
-  this->config.depthAttachmentFormat = depthAttachmentFormat;
+  this->config.rasterizationInfo.cullMode = builder.cullMode;
-  this->config.stencilAttachmentFormat = stencilAttachmentFormat;
+  this->config.rasterizationInfo.frontFace = builder.frontFace;
+
+  this->config.bindingDescriptions = builder.bindingDescriptions;
+  this->config.attributeDescriptions = builder.attributeDescriptions;
+  this->config.pipelineLayout = builder.pipelineLayout;
+  this->config.colorAttachmentFormats = builder.colorAttachmentFormats;
+  this->config.depthAttachmentFormat = builder.depthAttachmentFormat;
+  this->config.stencilAttachmentFormat = builder.stencilAttachmentFormat;
 
   vk::UniqueShaderModule vertexShaderModule =
-      createShaderModule(vertexShader.getSpirv());
+      createShaderModule(builder.vertexShader->getSpirv());
   vk::UniqueShaderModule fragmentShaderModule =
-      createShaderModule(fragmentShader.getSpirv());
+      createShaderModule(builder.fragmentShader->getSpirv());
   log::trace("created graphics shader modules");
 
   vk::PipelineShaderStageCreateInfo shaderStages[] = {
@@ -245,7 +255,7 @@ void GraphicsPipeline::setDefaultGraphicsPipelineConfig() {
   this->config.rasterizationInfo.polygonMode = vk::PolygonMode::eFill;
   this->config.rasterizationInfo.lineWidth = 1.0f;
   this->config.rasterizationInfo.cullMode = vk::CullModeFlagBits::eNone;
-  this->config.rasterizationInfo.frontFace = vk::FrontFace::eClockwise;
+  this->config.rasterizationInfo.frontFace = vk::FrontFace::eCounterClockwise;
   this->config.rasterizationInfo.depthBiasEnable = vk::False;
   this->config.rasterizationInfo.depthBiasConstantFactor = 0.0f;
   this->config.rasterizationInfo.depthBiasClamp = 0.0f;

engine/src/vulkan/pipelines/graphics_pipeline.hpp

@@ -41,14 +41,7 @@ class GraphicsPipeline : public Pipeline {
   ~GraphicsPipeline() override;
 
  private:
-  GraphicsPipeline(
+  explicit GraphicsPipeline(const Builder& builder);
-      Device& device, Shader& vertexShader, Shader& fragmentShader,
-      vk::PipelineLayout pipelineLayout,
-      std::vector<vk::Format> colorAttachmentFormats,
-      vk::Format depthAttachmentFormat, vk::Format stencilAttachmentFormat,
-      std::vector<vk::VertexInputBindingDescription> bindingDescriptions,
-      std::vector<vk::VertexInputAttributeDescription> attributeDescriptions,
-      bool alphaBlending);
 
   void setDefaultGraphicsPipelineConfig();
 
@@ -72,6 +65,14 @@ class GraphicsPipeline::Builder {
       std::vector<vk::VertexInputAttributeDescription> attributeDescriptions);
   // Straight (non-premultiplied) "over" blending on every color attachment.
   Builder& setAlphaBlending(bool enabled = true);
+  // Only matters with a depth attachment. Defaults to testing and writing
+  // with eLess.
+  Builder& setDepthTest(bool test, bool write,
+                        vk::CompareOp compareOp = vk::CompareOp::eLess);
+  // Defaults to no culling, with counter-clockwise triangles facing front.
+  Builder& setCullMode(
+      vk::CullModeFlags cullMode,
+      vk::FrontFace frontFace = vk::FrontFace::eCounterClockwise);
 
   std::unique_ptr<GraphicsPipeline> build() const;
 
@@ -87,6 +88,13 @@ class GraphicsPipeline::Builder {
   std::vector<vk::VertexInputBindingDescription> bindingDescriptions{};
   std::vector<vk::VertexInputAttributeDescription> attributeDescriptions{};
   bool alphaBlending = false;
+  bool depthTest = true;
+  bool depthWrite = true;
+  vk::CompareOp depthCompareOp = vk::CompareOp::eLess;
+  vk::CullModeFlags cullMode = vk::CullModeFlagBits::eNone;
+  vk::FrontFace frontFace = vk::FrontFace::eCounterClockwise;
+
+  friend class GraphicsPipeline;
 };
 
 }  // namespace sophia

engine/src/vulkan/swapchain.cpp

@@ -215,8 +215,7 @@ vk::Extent2D Swapchain::chooseExtent(
 
 vk::Format Swapchain::findDepthFormat() {
   return this->device.findSupportedFormat(
-      {vk::Format::eD32Sfloat, vk::Format::eD32SfloatS8Uint,
+      {vk::Format::eD32Sfloat, vk::Format::eX8D24UnormPack32},
-       vk::Format::eD24UnormS8Uint},
       vk::ImageTiling::eOptimal,
       vk::FormatFeatureFlagBits::eDepthStencilAttachment);
 }

examples/boids_2d/main.cpp

@@ -141,8 +141,8 @@ class Boids2D : public sophia::Application {
         cameraEntity.getComponent<sophia::TransformComponent>().position;
     if (scrollLeft) cameraPosition.x -= scrollDistance;
     if (scrollRight) cameraPosition.x += scrollDistance;
-    if (scrollUp) cameraPosition.y -= scrollDistance;
+    if (scrollUp) cameraPosition.y += scrollDistance;
-    if (scrollDown) cameraPosition.y += scrollDistance;
+    if (scrollDown) cameraPosition.y -= scrollDistance;
 
     // One world unit per pixel, whatever size the viewport is.
     cameraEntity.getComponent<sophia::CameraComponent>().ortho.height =

examples/cube/CMakeLists.txt

@@ -0,0 +1,3 @@
+add_executable(cube main.cpp)
+
+target_link_libraries(cube PRIVATE ${PROJECT_NAME})

examples/cube/main.cpp

@@ -0,0 +1,50 @@
+#include <glm/gtc/quaternion.hpp>
+#include <sophia/application.hpp>
+#include <sophia/components.hpp>
+#include <sophia/entity.hpp>
+#include <sophia/primitives.hpp>
+#include <sophia/scene_view.hpp>
+
+// A spinning cube seen through a perspective camera.
+class Cube : public sophia::Application {
+ public:
+  Cube() : Application{{.width = 800, .height = 600, .name = "Cube"}} {
+    debugUI().showFrameStats(true);
+  }
+
+  void onCreate() override {
+    sophia::SceneHandle sceneHandle = scenes().create();
+    sophia::Scene& scene = scenes().get(sceneHandle);
+
+    sophia::Entity camera = scene.createCamera();
+    camera.getComponent<sophia::CameraComponent>().projection =
+        sophia::CameraComponent::Projection::Perspective;
+    camera.getComponent<sophia::TransformComponent>().position = {0.f, 0.f,
+                                                                  3.f};
+
+    // Unlit, so color each face by its normal to tell them apart.
+    sophia::MeshData data = sophia::primitives::cube();
+    for (sophia::MeshVertex& vertex : data.vertices) {
+      vertex.color = glm::vec4{vertex.normal * 0.5f + 0.5f, 1.f};
+    }
+
+    cube = scene.createEntity("Cube");
+    cube.addComponent<sophia::MeshComponent>(sophia::MeshComponent{
+        .handle = resources().create<sophia::Mesh>(data)});
+
+    sceneViews().create({
+        .scene = sceneHandle,
+    });
+  }
+
+  void onUpdate(const sophia::FrameInfo& frameInfo) override {
+    auto angle = static_cast<float>(frameInfo.elapsedTime);
+    cube.getComponent<sophia::TransformComponent>().rotation =
+        glm::angleAxis(angle, glm::normalize(glm::vec3{1.f, 1.f, 0.f}));
+  }
+
+ private:
+  sophia::Entity cube;
+};
+
+SOPHIA_MAIN(Cube)

third_party/CMakeLists.txt

@@ -78,3 +78,17 @@ target_link_libraries(imgui PRIVATE
 if(UNIX AND NOT APPLE)
   target_compile_options(imgui PRIVATE -fPIC)
 endif()
+
+# ImGuizmo: only the transform gizmo. The repo's own CMakeLists also builds
+# its other widgets, and doesn't link imgui when used as a subdirectory.
+add_library(imguizmo STATIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/ImGuizmo/src/ImGuizmo.cpp
+)
+
+target_include_directories(imguizmo PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/ImGuizmo/src
+)
+
+target_link_libraries(imguizmo PUBLIC
+  imgui
+)