editor/main.cpp

@@ -20,7 +20,7 @@ class Editor : public sophia::Application {
     panels().emplace<AssetBrowserPanel>();
     sophia::RenderTargetHandle sceneTarget =
         resources().create<sophia::RenderTarget>();
-    setSceneTarget(sceneTarget);
+    views().create({.scene = scenes().create(), .target = sceneTarget});
     panels().emplace<ViewportPanel>(ui(), sceneTarget);
 
     panels().setDefaultLayout(

engine/include/sophia/application.hpp

@@ -10,6 +10,7 @@
 #include <sophia/math.hpp>
 #include <sophia/resource_registry_ref.hpp>
 #include <sophia/scene_registry.hpp>
+#include <sophia/scene_view_registry.hpp>
 #include <sophia/types.hpp>
 #include <sophia/ui/debug_ui.hpp>
 #include <sophia/ui/panel_registry.hpp>
@@ -46,6 +47,7 @@ class Application {
   ResourceRegistryRef resources();
   PanelRegistry& panels() { return this->panelRegistry; }
   SceneRegistry& scenes() { return this->sceneRegistry; }
+  SceneViewRegistry& views() { return this->sceneViewRegistry; }
   UI& ui() { return this->_ui; }
 
   DebugUI& debugUI() { return this->_debugUI; }
@@ -58,16 +60,6 @@ class Application {
 
   void drawMesh(MeshHandle handle, const glm::mat4& transform);
 
-  /**
-   * !TEMP !TODO remove this func eventually
-   * Chooses where the scene is rendered. An invalid handle (the default) means
-   * the swapchain; a target created with
-   * ResourceRegistryRef::create<RenderTarget>() redirects it offscreen, and the
-   * swapchain then only receives the UI. FrameInfo::currentFramebufferExtent
-   * and the camera projection follow the target's size.
-   */
-  void setSceneTarget(RenderTargetHandle handle);
-
  private:
   friend class Canvas;
 
@@ -79,6 +71,7 @@ class Application {
 
   PanelRegistry panelRegistry;
   SceneRegistry sceneRegistry;
+  SceneViewRegistry sceneViewRegistry;
   UI _ui;
 
   DebugUI _debugUI;

engine/include/sophia/handles.hpp

@@ -37,10 +37,12 @@ class Mesh;
 class Panel;
 class RenderTarget;
 class Scene;
+struct SceneView;
 
 using MeshHandle = Handle<Mesh>;
 using PanelHandle = Handle<Panel>;
 using RenderTargetHandle = Handle<RenderTarget>;
 using SceneHandle = Handle<Scene>;
+using SceneViewHandle = Handle<SceneView>;
 
 }  // namespace sophia

engine/include/sophia/scene_view.hpp

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <sophia/entity.hpp>
+#include <sophia/handles.hpp>
+#include <sophia/math.hpp>
+#include <sophia/scene.hpp>
+
+namespace sophia {
+
+enum class ClearFlags : u8 {
+  None = 0,
+  Color = 1 << 0,
+  Depth = 1 << 1,
+  Stencil = 1 << 2,
+  All = Color | Depth | Stencil
+};
+
+struct SceneView {
+  SceneHandle scene = INVALID_HANDLE;
+  RenderTargetHandle target = INVALID_HANDLE;
+  Entity camera;
+
+  vec4 viewport{0.0f, 0.0f, 1.0f, 1.0f};
+
+  vec4 clearColor{0.f, 0.f, 0.f, 1.f};
+  ClearFlags clearFlags = ClearFlags::All;
+
+  u32 priority = 0;  // Lower priority renders first
+  u32 layerMask = 0xFFFFFFFF;
+
+  bool enabled = true;  // Disabled views are kept but not rendered
+};
+
+}  // namespace sophia

engine/include/sophia/scene_view_registry.hpp

@@ -0,0 +1,86 @@
+#pragma once
+
+#include <algorithm>
+#include <sophia/handles.hpp>
+#include <sophia/scene_view.hpp>
+#include <sophia/util/pool.hpp>
+#include <utility>
+#include <vector>
+
+namespace sophia {
+
+/**
+ * Every live SceneView. The application renders all enabled views each frame,
+ * in ascending priority order, before the UI.
+ */
+class SceneViewRegistry {
+ public:
+  SceneViewRegistry(const SceneViewRegistry&) = delete;
+  SceneViewRegistry& operator=(const SceneViewRegistry&) = delete;
+
+  SceneViewRegistry() = default;
+  ~SceneViewRegistry() = default;
+
+  SceneViewHandle create(const SceneView& view = {}) {
+    isRenderQueueDirty = true;
+    return pool.create(view);
+  }
+
+  const SceneView& get(SceneViewHandle handle) const {
+    return pool.get(handle);
+  }
+
+  SceneView& get(SceneViewHandle handle) {
+    isRenderQueueDirty = true;
+    return pool.get(handle);
+  }
+
+  void release(SceneViewHandle handle) {
+    isRenderQueueDirty = true;
+    pool.release(handle);
+  }
+
+  bool isAlive(SceneViewHandle handle) const { return pool.isAlive(handle); }
+
+  u32 size() const { return pool.size(); }
+
+  template <typename Fn>
+  void forEach(Fn&& fn) {
+    isRenderQueueDirty = true;
+    pool.forEach(std::forward<Fn>(fn));
+  }
+
+  template <typename Fn>
+  void forEach(Fn&& fn) const {
+    pool.forEach(std::forward<Fn>(fn));
+  }
+
+  const std::vector<SceneViewHandle>& GetRenderQueue() const {
+    if (isRenderQueueDirty) {
+      rebuildRenderQueue();
+    }
+    return renderQueue;
+  }
+
+ private:
+  void rebuildRenderQueue() const {
+    renderQueue.clear();
+    pool.forEachWithHandle([&](SceneViewHandle handle, const SceneView& view) {
+      if (view.enabled) {
+        renderQueue.push_back(handle);
+      }
+    });
+
+    std::ranges::stable_sort(renderQueue, {}, [this](SceneViewHandle handle) {
+      return pool.get(handle).priority;
+    });
+    isRenderQueueDirty = false;
+  }
+
+  Pool<SceneView> pool{"SceneView"};
+
+  mutable std::vector<SceneViewHandle> renderQueue;
+  mutable bool isRenderQueueDirty = true;
+};
+
+}  // namespace sophia

engine/src/application.cpp

@@ -1,9 +1,11 @@
 #include <imgui.h>
 
+#include <algorithm>
 #include <array>
 #include <chrono>
 #include <cstddef>
 #include <glm/glm.hpp>
+#include <map>
 #include <sophia/application.hpp>
 #include <sophia/util/logger.hpp>
 #include <string>
@@ -15,6 +17,7 @@
 #include "rendering/model_render_system.hpp"
 #include "rendering/render_context.hpp"
 #include "rendering/render_graph.hpp"
+#include "rendering/scene_renderer.hpp"
 #include "resources/mesh.hpp"
 #include "resources/render_target.hpp"
 #include "resources/resource_registry.hpp"
@@ -43,35 +46,8 @@ std::vector<std::string> commandLineArgs;
 
 constexpr ClearColor CLEAR_COLOR = {0.01f, 0.01f, 0.02f, 1.0f};
 
-void beginColorPass(vk::CommandBuffer commandBuffer, vk::ImageView view,
-                    vk::Extent2D extent) {
-  vk::ClearValue clearValue{};
-  clearValue.color = vk::ClearColorValue{CLEAR_COLOR};
-
-  vk::RenderingAttachmentInfo colorAttachment{};
-  colorAttachment.imageView = view;
-  colorAttachment.imageLayout = vk::ImageLayout::eColorAttachmentOptimal;
-  colorAttachment.loadOp = vk::AttachmentLoadOp::eClear;
-  colorAttachment.storeOp = vk::AttachmentStoreOp::eStore;
-  colorAttachment.clearValue = clearValue;
-
-  vk::RenderingInfo renderingInfo{};
-  renderingInfo.renderArea = vk::Rect2D{{0, 0}, extent};
-  renderingInfo.layerCount = 1;
-  renderingInfo.colorAttachmentCount = 1;
-  renderingInfo.pColorAttachments = &colorAttachment;
-
-  commandBuffer.beginRendering(renderingInfo);
-
-  vk::Viewport viewport{0.0f,
-                        0.0f,
-                        static_cast<float>(extent.width),
-                        static_cast<float>(extent.height),
-                        0.0f,
-                        1.0f};
-  vk::Rect2D scissor{{0, 0}, extent};
-  commandBuffer.setViewport(0, viewport);
-  commandBuffer.setScissor(0, scissor);
+bool hasFlag(ClearFlags flags, ClearFlags flag) {
+  return (static_cast<u8>(flags) & static_cast<u8>(flag)) != 0;
 }
 
 }  // namespace
@@ -88,6 +64,8 @@ class Application::Impl {
 
   void run() {
     ModelRenderSystem modelRenderSystem{device, renderContext};
+    SceneRenderer sceneRenderer{this->application.sceneRegistry,
+                                this->resourceRegistry};
     ImGuiRenderer imguiRenderer{window, device, renderContext.getImageFormat(),
                                 renderContext.getImageCount(),
                                 this->resourceRegistry};
@@ -106,6 +84,7 @@ class Application::Impl {
     auto& renderTargetPool = this->resourceRegistry.renderTargetPool;
 
     PanelRegistry& panelRegistry = this->application.panelRegistry;
+    const SceneViewRegistry& sceneViews = this->application.sceneViewRegistry;
 
     imguiRenderer.setDefaultLayout(panelRegistry.getDefaultLayout());
 
@@ -128,17 +107,10 @@ class Application::Impl {
       // frame's work (or ImGui's references to the targets) is recorded.
       renderTargetPool.applyPendingResizes();
 
-      RenderTarget* sceneTarget =
-          this->sceneTargetHandle.isValid()
-              ? &renderTargetPool.get(this->sceneTargetHandle)
-              : nullptr;
-
       vk::Extent2D extent = renderContext.getExtent();
-      vk::Extent2D sceneExtent =
-          sceneTarget ? sceneTarget->getExtent() : extent;
       FrameInfo frameInfo{frameIndex, elapsedTime, deltaTime,
-                          glm::vec2(static_cast<float>(sceneExtent.width),
-                                    static_cast<float>(sceneExtent.height)),
+                          glm::vec2(static_cast<float>(extent.width),
+                                    static_cast<float>(extent.height)),
                           this->application.camera};
       this->application.onUpdate(frameInfo);
       this->application.camera.setProjection(
@@ -166,31 +138,54 @@ class Application::Impl {
                        this->drawCalls.end());
       this->drawCalls.clear();
 
-      if (sceneTarget) {
-        Image& targetImage = sceneTarget->getImage();
-        targetImage.transitionLayout(commandBuffer,
-                                     vk::ImageLayout::eColorAttachmentOptimal);
-        beginColorPass(commandBuffer, targetImage.getView(), sceneExtent);
-        modelRenderSystem.render(commandBuffer, instances, frameInfo);
-        commandBuffer.endRendering();
-        targetImage.transitionLayout(commandBuffer,
-                                     vk::ImageLayout::eShaderReadOnlyOptimal);
-      }
-
       RenderGraph graph;
       ImageRef backbuffer =
           graph.importImage(renderContext.getCurrentImage(), Access::Present);
 
+      std::map<RenderTargetHandle, ImageRef> viewTargets;
+      for (SceneViewHandle handle : sceneViews.GetRenderQueue()) {
+        const SceneView& view = sceneViews.get(handle);
+        if (!this->application.sceneRegistry.isAlive(view.scene) ||
+            !renderTargetPool.isAlive(view.target)) {
+          continue;
+        }
+
+        auto [it, inserted] = viewTargets.try_emplace(view.target);
+        if (inserted) {
+          it->second =
+              graph.importImage(renderTargetPool.get(view.target).getImage(),
+                                Access::SampledRead);
+        }
+
+        const vec4& color = view.clearColor;
+        graph.addPass(
+            "scene view",
+            [&](RenderGraph::PassBuilder& pass) {
+              pass.writeColor(it->second,
+                              hasFlag(view.clearFlags, ClearFlags::Color)
+                                  ? vk::AttachmentLoadOp::eClear
+                                  : vk::AttachmentLoadOp::eLoad,
+                              {color.r, color.g, color.b, color.a});
+            },
+            [&sceneRenderer, &sceneViews, handle](vk::CommandBuffer) {
+              const SceneView& view = sceneViews.get(handle);
+              if (view.camera) {
+                sceneRenderer.render(view);
+              }
+            });
+      }
+
       graph.addPass(
           "main",
           [&](RenderGraph::PassBuilder& pass) {
             pass.writeColor(backbuffer, vk::AttachmentLoadOp::eClear,
                             CLEAR_COLOR);
+            for (const auto& [handle, target] : viewTargets) {
+              pass.sample(target);
+            }
           },
           [&](vk::CommandBuffer commandBuffer) {
-            if (!sceneTarget) {
             modelRenderSystem.render(commandBuffer, instances, frameInfo);
-            }
 
             imguiRenderer.endFrame(commandBuffer);
           });
@@ -237,10 +232,6 @@ class Application::Impl {
     this->drawCalls.push_back({&mesh, transform});
   }
 
-  void setSceneTarget(RenderTargetHandle handle) {
-    this->sceneTargetHandle = handle;
-  }
-
   ResourceRegistry& getResourceRegistry() { return resourceRegistry; }
 
  private:
@@ -253,8 +244,6 @@ class Application::Impl {
 
   std::vector<std::unique_ptr<Mesh>> meshes;
   std::vector<ModelRenderSystem::MeshInstance> drawCalls;
-
-  RenderTargetHandle sceneTargetHandle = RenderTargetHandle::invalid();
 };
 
 void Application::setCommandLineArgs(int argc, const char* const* argv) {
@@ -281,10 +270,6 @@ void Application::pushMesh(std::vector<CanvasVertex> vertices,
   impl->pushMesh(std::move(vertices), std::move(indices));
 }
 
-void Application::setSceneTarget(RenderTargetHandle handle) {
-  impl->setSceneTarget(handle);
-}
-
 void Application::clearMeshes() { impl->clearMeshes(); }
 
 void Application::drawMesh(MeshHandle handle, const glm::mat4& transform) {