Render Graph concept started!

engine/include/sophia/components.hpp

@@ -34,4 +34,36 @@ struct MeshComponent {
   MeshHandle handle;
 };
 
+struct CameraComponent {
+  struct Orthographic {
+    float height = 10.f;
+    float nearPlane = -1.f;
+    float farPlane = 1.f;
+  };
+
+  struct Perspective {
+    float fov = glm::radians(60.f);
+    float nearPlane = 0.1f;
+    float farPlane = 100.f;
+  };
+
+  enum class Projection { Orthographic, Perspective };
+
+  Projection projection = Projection::Orthographic;
+  Orthographic ortho;
+  Perspective perspective;
+
+  glm::mat4 getProjection(float aspect) const {
+    if (projection == Projection::Perspective) {
+      return glm::perspective(perspective.fov, aspect, perspective.nearPlane,
+                              perspective.farPlane);
+    }
+
+    float halfHeight = ortho.height / 2.f;
+    float halfWidth = halfHeight * aspect;
+    return glm::ortho(-halfWidth, halfWidth, -halfHeight, halfHeight,
+                      ortho.nearPlane, ortho.farPlane);
+  }
+};
+
 }  // namespace sophia

engine/src/application.cpp

@@ -21,6 +21,8 @@
 #include "pipelines/graphics_pipeline.hpp"
 #include "render_context.hpp"
 #include "render_target.hpp"
+#include "rendering/render_graph.hpp"
+#include "resources/resource_registry.hpp"
 #include "shader.hpp"
 #include "systems/model_render_system.hpp"
 #include "window.hpp"
@@ -42,11 +44,12 @@ struct PushConstants {
 
 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 =
+  clearValue.color = vk::ClearColorValue{CLEAR_COLOR};
-      vk::ClearColorValue{std::array<float, 4>{0.01f, 0.01f, 0.02f, 1.0f}};
 
   vk::RenderingAttachmentInfo colorAttachment{};
   colorAttachment.imageView = view;
@@ -83,13 +86,14 @@ class Application::Impl {
         config{config},
         window{config.width, config.height, config.name},
         device{&window},
-        renderContext{window, device} {}
+        renderContext{window, device},
+        resourceRegistry{device, renderContext.getImageFormat()} {}
 
   void run() {
     ModelRenderSystem modelRenderSystem{device, renderContext};
     ImGuiRenderer imguiRenderer{window, device, renderContext.getImageFormat(),
                                 renderContext.getImageCount(),
-                                this->application.resourceRegistry};
+                                this->resourceRegistry};
     this->application._ui.renderer = &imguiRenderer;
 
     this->application.consoleCommandRegistry.registerCommand(
@@ -100,8 +104,13 @@ class Application::Impl {
         });
 
     this->application.onCreate();
-    imguiRenderer.setDefaultLayout(
+
-        this->application.panelRegistry.getDefaultLayout());
+    auto& meshPool = this->resourceRegistry.meshPool;
+    auto& renderTargetPool = this->resourceRegistry.renderTargetPool;
+
+    PanelRegistry& panelRegistry = this->application.panelRegistry;
+
+    imguiRenderer.setDefaultLayout(panelRegistry.getDefaultLayout());
 
     auto startTime = std::chrono::high_resolution_clock::now();
     auto currentTime = startTime;
@@ -120,12 +129,11 @@ class Application::Impl {
 
       // Resizing waits for the GPU, so it has to happen before any of this
       // frame's work (or ImGui's references to the targets) is recorded.
-      this->application.resourceRegistry.applyPendingResizes();
+      renderTargetPool.applyPendingResizes();
 
       RenderTarget* sceneTarget =
           this->sceneTargetHandle.isValid()
-              ? &this->application.resourceRegistry.getRenderTarget(
+              ? &renderTargetPool.get(this->sceneTargetHandle)
-                    this->sceneTargetHandle)
               : nullptr;
 
       vk::Extent2D extent = renderContext.getExtent();
@@ -149,7 +157,7 @@ class Application::Impl {
 
       imguiRenderer.beginFrame();
 
-      this->application.panelRegistry.update(frameInfo);
+      panelRegistry.update(frameInfo);
       this->application.onRender();
 
       std::vector<ModelRenderSystem::MeshInstance> instances;
@@ -172,21 +180,25 @@ class Application::Impl {
                                      vk::ImageLayout::eShaderReadOnlyOptimal);
       }
 
-      renderContext.transitionCurrentImage(
+      RenderGraph graph;
-          commandBuffer, vk::ImageLayout::eColorAttachmentOptimal);
+      ImageRef backbuffer =
-      beginColorPass(commandBuffer, renderContext.getCurrentImageView(),
+          graph.importImage(renderContext.getCurrentImage(), Access::Present);
-                     extent);
 
+      graph.addPass(
+          "main",
+          [&](RenderGraph::PassBuilder& pass) {
+            pass.writeColor(backbuffer, vk::AttachmentLoadOp::eClear,
+                            CLEAR_COLOR);
+          },
+          [&](vk::CommandBuffer commandBuffer) {
             if (!sceneTarget) {
               modelRenderSystem.render(commandBuffer, instances, frameInfo);
             }
 
             imguiRenderer.endFrame(commandBuffer);
+          });
 
-      commandBuffer.endRendering();
+      graph.execute(commandBuffer);
-
-      renderContext.transitionCurrentImage(commandBuffer,
-                                           vk::ImageLayout::ePresentSrcKHR);
 
       renderContext.endFrame();
 
@@ -232,11 +244,7 @@ class Application::Impl {
     this->sceneTargetHandle = handle;
   }
 
-  u32 getColorFormat() const {
+  ResourceRegistry& getResourceRegistry() { return resourceRegistry; }
-    return static_cast<u32>(this->renderContext.getImageFormat());
-  }
-
-  Device& getDevice() { return device; }
 
  private:
   Application& application;
@@ -244,6 +252,7 @@ class Application::Impl {
   Window window;
   Device device;
   RenderContext renderContext;
+  ResourceRegistry resourceRegistry;
 
   std::vector<std::unique_ptr<Mesh>> meshes;
   std::vector<ModelRenderSystem::MeshInstance> drawCalls;
@@ -259,14 +268,17 @@ Application::Application(const Config& config)
     : impl{std::make_unique<Impl>(*this, config)},
       canvas{this},
       args{std::move(commandLineArgs)},
-      resourceRegistry{impl->getDevice(), impl->getColorFormat()},
+      _ui{ResourceRegistryRef{impl->getResourceRegistry()}},
-      _ui{resourceRegistry},
       _debugUI{this->panelRegistry, this->consoleCommandRegistry} {}
 
 Application::~Application() = default;
 
 void Application::run() { impl->run(); }
 
+ResourceRegistryRef Application::resources() {
+  return ResourceRegistryRef{impl->getResourceRegistry()};
+}
+
 void Application::pushMesh(std::vector<CanvasVertex> vertices,
                            std::vector<u32> indices) {
   impl->pushMesh(std::move(vertices), std::move(indices));
@@ -279,7 +291,7 @@ void Application::setSceneTarget(RenderTargetHandle handle) {
 void Application::clearMeshes() { impl->clearMeshes(); }
 
 void Application::drawMesh(MeshHandle handle, const glm::mat4& transform) {
-  impl->drawMesh(resourceRegistry.get<Mesh>(handle), transform);
+  impl->drawMesh(impl->getResourceRegistry().meshPool.get(handle), transform);
 }
 
 }  // namespace sophia

engine/src/rendering/render_graph.cpp

@@ -0,0 +1,159 @@
+#include "rendering/render_graph.hpp"
+
+#include <sophia/util/assert.hpp>
+#include <utility>
+
+namespace sophia {
+
+ImageRef RenderGraph::importImage(Image& image, Access finalAccess) {
+  ImageRef ref{static_cast<u32>(this->images.size())};
+  this->images.push_back({&image, finalAccess, image.getAccessState()});
+  return ref;
+}
+
+void RenderGraph::addPass(std::string name, const SetupFn& setup,
+                          ExecuteFn execute) {
+  Pass& pass = this->passes.emplace_back();
+  pass.name = std::move(name);
+  pass.execute = std::move(execute);
+
+  PassBuilder builder{*this, pass};
+  setup(builder);
+}
+
+void RenderGraph::execute(vk::CommandBuffer commandBuffer) {
+  for (Pass& pass : this->passes) {
+    this->recordPass(commandBuffer, pass);
+  }
+
+  PendingBarriers pending;
+  for (u32 i = 0; i < this->images.size(); i++) {
+    this->transitionTo(ImageRef{i}, getAccessState(this->images[i].finalAccess),
+                       pending);
+  }
+  this->flush(commandBuffer, pending);
+
+  for (ImportedImage& imported : this->images) {
+    imported.image->recordLayout(imported.state.layout);
+  }
+
+  this->passes.clear();
+}
+
+void RenderGraph::transitionTo(ImageRef ref, const AccessState& next,
+                               PendingBarriers& pending) {
+  SOPHIA_ASSERT(ref.isValid() && ref.index < this->images.size(),
+                "ImageRef doesn't belong to this graph");
+
+  ImportedImage& imported = this->images[ref.index];
+
+  if (needsBarrier(imported.state, next)) {
+    pending.barriers.push_back(makeImageBarrier(
+        imported.image->get(), imported.image->getSubresourceRange(),
+        imported.state, next));
+    pending.srcStages |= imported.state.stage;
+    pending.dstStages |= next.stage;
+    imported.state = next;
+  } else {
+    // Same-layout read after read. Nothing to record, but a later write has
+    // to wait on this reader too.
+    imported.state.stage |= next.stage;
+    imported.state.access |= next.access;
+  }
+}
+
+void RenderGraph::flush(vk::CommandBuffer commandBuffer,
+                        PendingBarriers& pending) {
+  if (pending.barriers.empty()) {
+    return;
+  }
+
+  commandBuffer.pipelineBarrier(pending.srcStages, pending.dstStages, {},
+                                nullptr, nullptr, pending.barriers);
+  pending = PendingBarriers{};
+}
+
+void RenderGraph::recordPass(vk::CommandBuffer commandBuffer, Pass& pass) {
+  PendingBarriers pending;
+  for (const ImageUse& use : pass.uses) {
+    this->transitionTo(use.image, getAccessState(use.access), pending);
+  }
+  this->flush(commandBuffer, pending);
+
+  if (pass.colorAttachments.empty()) {
+    pass.execute(commandBuffer);
+    return;
+  }
+
+  std::vector<vk::RenderingAttachmentInfo> attachments;
+  attachments.reserve(pass.colorAttachments.size());
+
+  vk::Extent3D imageExtent =
+      this->images[pass.colorAttachments.front().image.index]
+          .image->getExtent();
+  vk::Extent2D extent{imageExtent.width, imageExtent.height};
+
+  for (const ColorAttachment& color : pass.colorAttachments) {
+    const Image& image = *this->images[color.image.index].image;
+    SOPHIA_ASSERT(image.getExtent().width == extent.width &&
+                      image.getExtent().height == extent.height,
+                  "Pass", pass.name,
+                  "has color attachments of different sizes");
+
+    vk::RenderingAttachmentInfo attachment{};
+    attachment.imageView = image.getView();
+    attachment.imageLayout = vk::ImageLayout::eColorAttachmentOptimal;
+    attachment.loadOp = color.loadOp;
+    attachment.storeOp = vk::AttachmentStoreOp::eStore;
+    attachment.clearValue.color = vk::ClearColorValue{color.clearColor};
+    attachments.push_back(attachment);
+  }
+
+  vk::RenderingInfo renderingInfo{};
+  renderingInfo.renderArea = vk::Rect2D{{0, 0}, extent};
+  renderingInfo.layerCount = 1;
+  renderingInfo.colorAttachmentCount = static_cast<u32>(attachments.size());
+  renderingInfo.pColorAttachments = attachments.data();
+
+  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);
+
+  pass.execute(commandBuffer);
+
+  commandBuffer.endRendering();
+}
+
+RenderGraph::PassBuilder& RenderGraph::PassBuilder::writeColor(
+    ImageRef image, vk::AttachmentLoadOp loadOp, ClearColor clearColor) {
+  this->use(image, Access::ColorWrite);
+  this->pass.colorAttachments.push_back({image, loadOp, clearColor});
+  return *this;
+}
+
+RenderGraph::PassBuilder& RenderGraph::PassBuilder::sample(ImageRef image) {
+  return this->use(image, Access::SampledRead);
+}
+
+RenderGraph::PassBuilder& RenderGraph::PassBuilder::use(ImageRef image,
+                                                        Access access) {
+  SOPHIA_ASSERT(image.isValid() && image.index < this->graph.images.size(),
+                "ImageRef doesn't belong to this graph");
+  for (const ImageUse& existing : this->pass.uses) {
+    SOPHIA_ASSERT(existing.image.index != image.index, "Pass", this->pass.name,
+                  "uses the same image twice");
+  }
+
+  this->pass.uses.push_back({image, access});
+  return *this;
+}
+
+}  // namespace sophia

engine/src/rendering/render_graph.hpp

@@ -0,0 +1,147 @@
+#pragma once
+
+#include <array>
+#include <functional>
+#include <sophia/types.hpp>
+#include <string>
+#include <vector>
+#include <vulkan/vulkan.hpp>
+
+#include "image.hpp"
+#include "rendering/access.hpp"
+
+namespace sophia {
+
+/**
+ * Names an image within one RenderGraph. Only valid for the graph that
+ * returned it.
+ */
+struct ImageRef {
+  u32 index = INVALID_INDEX;
+
+  static constexpr u32 INVALID_INDEX = 0xFFFFFFFF;
+
+  bool isValid() const { return this->index != INVALID_INDEX; }
+};
+
+using ClearColor = std::array<float, 4>;
+
+/**
+ * A frame's passes and the images they touch, recorded into a single command
+ * 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.
+ *
+ * Built fresh every frame:
+ *
+ *   RenderGraph graph;
+ *   ImageRef backbuffer = graph.importImage(swapchainImage, Access::Present);
+ *   graph.addPass(
+ *       "main", [&](PassBuilder& pass) { pass.writeColor(backbuffer); },
+ *       [&](vk::CommandBuffer cb) { draw(cb); });
+ *   graph.execute(commandBuffer);
+ *
+ * Imported images start in whatever layout Image reports and are left in
+ * their final access when execute() returns, with the Image's tracked layout
+ * updated to match.
+ */
+class RenderGraph {
+ public:
+  class PassBuilder;
+
+  using SetupFn = std::function<void(PassBuilder&)>;
+  using ExecuteFn = std::function<void(vk::CommandBuffer)>;
+
+  RenderGraph() = default;
+
+  RenderGraph(const RenderGraph&) = delete;
+  RenderGraph& operator=(const RenderGraph&) = delete;
+
+  /**
+   * Brings an image the graph doesn't own into it. It must outlive
+   * execute(). After the last pass it is transitioned to `finalAccess`.
+   */
+  ImageRef importImage(Image& image, Access finalAccess);
+
+  /**
+   * 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.
+   */
+  void addPass(std::string name, const SetupFn& setup, ExecuteFn execute);
+
+  /**
+   * Records every pass, and the barriers between them, into `commandBuffer`.
+   */
+  void execute(vk::CommandBuffer commandBuffer);
+
+ private:
+  struct ImageUse {
+    ImageRef image;
+    Access access;
+  };
+
+  struct ColorAttachment {
+    ImageRef image;
+    vk::AttachmentLoadOp loadOp;
+    ClearColor clearColor;
+  };
+
+  struct Pass {
+    std::string name;
+    std::vector<ImageUse> uses;
+    std::vector<ColorAttachment> colorAttachments;
+    ExecuteFn execute;
+  };
+
+  struct ImportedImage {
+    Image* image;
+    Access finalAccess;
+    // What the image was last left in, as of the barriers recorded so far.
+    AccessState state;
+  };
+
+  struct PendingBarriers {
+    std::vector<vk::ImageMemoryBarrier> barriers;
+    vk::PipelineStageFlags srcStages;
+    vk::PipelineStageFlags dstStages;
+  };
+
+  void transitionTo(ImageRef ref, const AccessState& next,
+                    PendingBarriers& pending);
+  void flush(vk::CommandBuffer commandBuffer, PendingBarriers& pending);
+  void recordPass(vk::CommandBuffer commandBuffer, Pass& pass);
+
+  std::vector<ImportedImage> images;
+  std::vector<Pass> passes;
+};
+
+class RenderGraph::PassBuilder {
+ public:
+  /**
+   * Renders into `image` as a color attachment. Passes with one or more of
+   * these get rendering begun (and viewport/scissor set to the attachment's
+   * extent) before their execute callback runs.
+   */
+  PassBuilder& writeColor(
+      ImageRef image,
+      vk::AttachmentLoadOp loadOp = vk::AttachmentLoadOp::eClear,
+      ClearColor clearColor = {0.f, 0.f, 0.f, 1.f});
+
+  /** Samples `image` in a shader. */
+  PassBuilder& sample(ImageRef image);
+
+  /** Any other use, e.g. storage or transfer access. */
+  PassBuilder& use(ImageRef image, Access access);
+
+ private:
+  friend class RenderGraph;
+
+  PassBuilder(RenderGraph& graph, Pass& pass) : graph{graph}, pass{pass} {}
+
+  RenderGraph& graph;
+  Pass& pass;
+};
+
+}  // namespace sophia