Added pre compute functions for render graph node compute

SHADE_Engine/src/Graphics/MiddleEnd/Interface/SHGraphicsSystem.cpp

@@ -262,7 +262,7 @@ namespace SHADE
     /*-----------------------------------------------------------------------*/
     // Shadow map pass will have no resources bound at first. Lighting system will add resources to the node.
     // It will initially also not have any subpasses since they will be added for each light that casts shadows.
-    auto shadowMapPass = renderGraph->AddNode(SHGraphicsConstants::RenderGraphNodeNames::SHADOW_MAP_PASS.data(), {}, {});
+    auto shadowMapPassNode = renderGraph->AddNode(SHGraphicsConstants::RenderGraphNodeNames::SHADOW_MAP_PASS.data(), {}, {});
 
     /*-----------------------------------------------------------------------*/
     /* DEFERRED COMPOSITE NODE                                               */
@@ -279,17 +279,16 @@ namespace SHADE
       },
       { SHGraphicsConstants::RenderGraphNodeNames::GBUFFER_PASS .data()});
 
-    // Add subpass with exterior draw call to transition shadow maps
-    //auto shadowMapTransitionSubpass = deferredCompositeNode->AddSubpass("Shadow Map Transition", {}, {});
-    //shadowMapTransitionSubpass->AddExteriorDrawCalls([=](Handle<SHVkCommandBuffer> cmdBuffer, Handle<SHRenderer> renderer, uint32_t frameIndex)
-    //  {
-    //    lightingSubSystem->PrepareShadowMapsForRead(cmdBuffer);
-    //  });
 
     /*-----------------------------------------------------------------------*/
     /* DEFERRED COMPOSITE SUBPASS INIT                                       */
     /*-----------------------------------------------------------------------*/
-    deferredCompositeNode->AddNodeCompute("Deferred Composite", deferredCompositeShader, { "Position", "Normals", "Albedo", "Light Layer Indices", "SSAO Blur", "Scene" });
+    auto deferredCompositeCompute = deferredCompositeNode->AddNodeCompute("Deferred Composite", deferredCompositeShader, { "Position", "Normals", "Albedo", "Light Layer Indices", "SSAO Blur", "Scene" });
+    deferredCompositeCompute->AddPreComputeFunction([=](Handle<SHVkCommandBuffer> cmdBuffer, uint32_t frameIndex)
+      {
+        lightingSubSystem->PrepareShadowMapsForRead(cmdBuffer);
+      });
+
 
     /*-----------------------------------------------------------------------*/
     /* DEBUG DRAW PASS INIT                                                  */

SHADE_Engine/src/Graphics/RenderGraph/SHRenderGraphNode.cpp

@@ -129,20 +129,25 @@ namespace SHADE
     if (subpasses.empty())
       return;
 
+    uint32_t numValidSubpasses = std::count_if(subpasses.begin(), subpasses.end(), [](Handle<SHSubpass> subpass) {return !subpass->HasNoAttachments();});
+
     // Create subpass description and dependencies based on number of subpasses 
-    spDescs.resize(subpasses.size());
+    spDescs.resize(numValidSubpasses);
-    spDeps.resize(subpasses.size());
+    spDeps.resize(numValidSubpasses);
 
     // Now we want to loop through all attachments in all subpasses in the node and query
     // the resources being used. For each resource we want to query the type and record it
     // in bit fields (1 bit for each subpass). 
     uint32_t colorRead = 0, colorWrite = 0, depthRead = 0, depthWrite = 0, inputDependencies = 0;
 
-    uint32_t i = 0;
 
     // For all subpasses (see above description about bit field for this).
-    for (auto& subpass : subpasses)
+    for (uint32_t i = 0; auto& subpass : subpasses)
     {
+      // skip if subpass is not valid
+      if (subpass->HasNoAttachments())
+        continue;
+
       // Configure subpass description
       auto& desc = spDescs[i];
       desc.pColorAttachments = subpass->colorReferences.data();
@@ -198,8 +203,11 @@ namespace SHADE
 
     // Loop through all subpasses again but this time we use the bit field to initialize
     // the dependencies. 
-    for (i = 0; i < subpasses.size(); ++i)
+    for (uint32_t i = 0; auto & subpass : subpasses)
     {
+      if (subpass->HasNoAttachments())
+        continue;
+
       vk::PipelineStageFlags srcStage;
       vk::PipelineStageFlags dstStage;
       vk::AccessFlags        srcAccess;
@@ -257,6 +265,8 @@ namespace SHADE
 
       // initialize input descriptors
       subpasses[i]->CreateInputDescriptors();
+
+      ++i;
     }
   }
 
@@ -639,7 +649,7 @@ namespace SHADE
         subpasses[i]->Execute(commandBuffer, descPool, frameIndex);
 
         // Go to next subpass if not last subpass
-        if (i != static_cast<uint32_t>(subpasses.size()) - 1u)
+        if (i != static_cast<uint32_t>(subpasses.size()) - 1u && !subpasses[i]->HasNoAttachments())
           commandBuffer->NextSubpass();
       }
 

SHADE_Engine/src/Graphics/RenderGraph/SHRenderGraphNodeCompute.cpp

@@ -152,6 +152,11 @@ namespace SHADE
 
   void SHRenderGraphNodeCompute::Execute(Handle<SHVkCommandBuffer> cmdBuffer, uint32_t frameIndex) noexcept
   {
+    for (auto& fn : preComputeFunctions)
+    {
+    	fn (cmdBuffer, frameIndex);
+    }
+
     // bind the compute pipeline
     cmdBuffer->BindPipeline(computePipeline);
     
@@ -252,4 +257,9 @@ namespace SHADE
 
   }
 
+  void SHRenderGraphNodeCompute::AddPreComputeFunction(PreComputeFunction const& fn) noexcept
+  {
+    preComputeFunctions.push_back(fn);
+  }
+
 }

SHADE_Engine/src/Graphics/RenderGraph/SHRenderGraphNodeCompute.h

@@ -25,6 +25,10 @@ namespace SHADE
 
   class SHRenderGraphNodeCompute
   {
+  public:
+    using PreComputeFunction = std::function<void(Handle<SHVkCommandBuffer>, uint32_t)>;
+
+
   private:
     // Binding of set SHGraphicsConstants::DescriptorSetIndex::RENDERGRAPH_NODE_COMPUTE_RESOURCE
     struct ComputeResource
@@ -73,6 +77,9 @@ namespace SHADE
     //! Name of this node
     std::string name;
 
+    std::vector<PreComputeFunction> preComputeFunctions;
+
+
   private:
     /*-----------------------------------------------------------------------*/
     /* PRIVATE MEMBER FUNCTIONS                                              */
@@ -97,6 +104,7 @@ namespace SHADE
     void ModifyWriteDescBufferComputeResource (uint32_t binding, std::span<Handle<SHVkBuffer>> const& buffers, uint32_t offset, uint32_t range) noexcept;
     void ModifyWriteDescImageComputeResource(uint32_t binding, std::span<SHVkDescriptorSetGroup::viewSamplerLayout> const& viewSamplerLayouts) noexcept;
 
+    void AddPreComputeFunction (PreComputeFunction const& fn) noexcept;
 
     friend class SHRenderGraph;
     friend class SHRenderGraphNode;

SHADE_Engine/src/Graphics/RenderGraph/SHSubpass.cpp

@@ -211,6 +211,8 @@ namespace SHADE
   {
     commandBuffer->BeginLabeledSegment(name);
    
+    if (!HasNoAttachments())
+    {
       // Ensure correct transforms are provided
       superBatch->UpdateBuffers(frameIndex, descPool);
 
@@ -229,6 +231,7 @@ namespace SHADE
 
       // Draw all the batches
       superBatch->Draw(commandBuffer, frameIndex);
+    }
 
     // Draw all the exterior draw calls
     for (auto& drawCall : exteriorDrawCalls)