Added support for buffers to clear at the beginning of a pass.

include/RenderGraph/Attachment.hpp

@@ -238,6 +238,7 @@ namespace crg
 			Uniform = 0x01 << 0,
 			Storage = 0x01 << 1,
 			View = 0x01 << 2,
+			Clearable = 0x01 << 4,
 			UniformView = Uniform | View,
 			StorageView = Storage | View,
 		};
@@ -274,6 +275,11 @@ namespace crg
 			return hasFlag( Flag::View );
 		}
 
+		bool isClearable()const
+		{
+			return hasFlag( Flag::Clearable );
+		}
+
 		bool isUniformView()const
 		{
 			return isUniform() && isView();
@@ -402,6 +408,13 @@ namespace crg
 			return isBuffer() && buffer.isStorage();
 		}
 
+		bool isClearableBuffer()const
+		{
+			return isBuffer()
+				&& isOutput()
+				&& buffer.isClearable();
+		}
+
 		bool isStorageBufferView()const
 		{
 			return isBuffer() && buffer.isStorageView();

include/RenderGraph/FramePass.hpp

@@ -110,6 +110,14 @@ namespace crg
 			, VkDeviceSize range );
 		/**
 		*\brief
+		*	Creates a storage buffer attachment that will be cleared a the beginning of the pass.
+		*/
+		CRG_API void addClearableOutputStorageBuffer( Buffer buffer
+			, uint32_t binding
+			, VkDeviceSize offset
+			, VkDeviceSize range );
+		/**
+		*\brief
 		*	Creates a storage buffer attachment.
 		*/
 		CRG_API void addInOutStorageBuffer( Buffer buffer

source/RenderGraph/FramePass.cpp

@@ -322,6 +322,23 @@ namespace crg
 			, range } );
 	}
 
+	void FramePass::addClearableOutputStorageBuffer( Buffer buffer
+		, uint32_t binding
+		, VkDeviceSize offset
+		, VkDeviceSize range )
+	{
+		auto attachName = fpass::adjustName( *this, buffer.name ) + "OSB";
+		buffers.push_back( Attachment{ Attachment::FlagKind( Attachment::Flag::Output )
+			, *this
+			, binding
+			, std::move( attachName )
+			, ( BufferAttachment::FlagKind( BufferAttachment::Flag::Storage )
+				| BufferAttachment::FlagKind( BufferAttachment::Flag::Clearable ) )
+			, buffer
+			, offset
+			, range } );
+	}
+
 	void FramePass::addInOutStorageBuffer( Buffer buffer
 		, uint32_t binding
 		, VkDeviceSize offset

source/RenderGraph/RunnablePass.cpp

@@ -17,6 +17,17 @@ See LICENSE file in root folder.
 
 namespace crg
 {
+	namespace details
+	{
+		static constexpr VkDeviceSize getAlignedSize( VkDeviceSize size, VkDeviceSize align )
+		{
+			auto rem = size % align;
+			return ( rem
+				? size + ( align - rem )
+				: size );
+		}
+	}
+
 	//*********************************************************************************************
 
 	void convert( SemaphoreWaitArray const & toWait
@@ -429,6 +440,24 @@ namespace crg
 					auto buffer = attach.buffer;
 					auto currentState = context.getAccessState( buffer.buffer.buffer
 						, buffer.range );
+
+					if ( attach.isClearableBuffer() )
+					{
+						context.memoryBarrier( commandBuffer
+							, buffer.buffer.buffer
+							, buffer.range
+							, currentState.access
+							, currentState.pipelineStage
+							, { VK_ACCESS_TRANSFER_WRITE_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT } );
+						m_context.vkCmdFillBuffer( commandBuffer
+								, buffer.buffer.buffer
+								, buffer.range.offset == 0u ? 0u : details::getAlignedSize( buffer.range.offset, 4u )
+								, buffer.range.size == VK_WHOLE_SIZE ? VK_WHOLE_SIZE : details::getAlignedSize( buffer.range.size, 4u )
+								, 0u );
+						currentState.access = VK_ACCESS_TRANSFER_WRITE_BIT;
+						currentState.pipelineStage = VK_PIPELINE_STAGE_TRANSFER_BIT;
+					}
+
 					context.memoryBarrier( commandBuffer
 						, buffer.buffer.buffer
 						, buffer.range