renaming dir

engine/src/renderer/render_graph.hpp

@@ -0,0 +1,149 @@
+#pragma once
+
+#include <array>
+#include <functional>
+#include <sophia/types.hpp>
+#include <string>
+#include <vector>
+#include <vulkan/vulkan.hpp>
+
+#include "vulkan/access.hpp"
+#include "vulkan/image.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. `name` labels
+   * the pass's commands in debugging tools such as RenderDoc.
+   */
+  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);
+  void recordRendering(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