Render Graph concept started!

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