Implement buffer to buffer copy command

Added buffer copy command and support for VkBufferCopy regions.

Passes all tests in:
dEQP-VK.api.copy_and_blit.core.buffer_to_buffer

Bug b/118619338

Change-Id: Id69cd3f089b07343a7209290808c11d4c17f1a49
Reviewed-on: https://swiftshader-review.googlesource.com/c/23229
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
diff --git a/src/Vulkan/VkBuffer.cpp b/src/Vulkan/VkBuffer.cpp
index 7772420..1a772cc 100644
--- a/src/Vulkan/VkBuffer.cpp
+++ b/src/Vulkan/VkBuffer.cpp
@@ -69,6 +69,11 @@
 	memcpy(dstMemory, getOffsetPointer(pOffset), pSize);
 }
 
+void Buffer::copyTo(Buffer* dstBuffer, const VkBufferCopy& pRegion) const
+{
+	copyTo(dstBuffer->getOffsetPointer(pRegion.dstOffset), pRegion.size, pRegion.srcOffset);
+}
+
 void* Buffer::getOffsetPointer(VkDeviceSize offset) const
 {
 	return reinterpret_cast<char*>(memory) + offset;
diff --git a/src/Vulkan/VkBuffer.hpp b/src/Vulkan/VkBuffer.hpp
index 8bdf0e9..45645e5 100644
--- a/src/Vulkan/VkBuffer.hpp
+++ b/src/Vulkan/VkBuffer.hpp
@@ -33,6 +33,7 @@
 	void bind(VkDeviceMemory pDeviceMemory, VkDeviceSize pMemoryOffset);
 	void copyFrom(const void* srcMemory, VkDeviceSize size, VkDeviceSize offset);
 	void copyTo(void* dstMemory, VkDeviceSize size, VkDeviceSize offset) const;
+	void copyTo(Buffer* dstBuffer, const VkBufferCopy& pRegion) const;
 	void* getOffsetPointer(VkDeviceSize offset) const;
 
 private:
diff --git a/src/Vulkan/VkCommandBuffer.cpp b/src/Vulkan/VkCommandBuffer.cpp
index 013d3be..7525749 100644
--- a/src/Vulkan/VkCommandBuffer.cpp
+++ b/src/Vulkan/VkCommandBuffer.cpp
@@ -166,6 +166,24 @@
 	const VkImageCopy region;
 };
 
+struct BufferToBufferCopy : public CommandBuffer::Command
+{
+	BufferToBufferCopy(VkBuffer pSrcBuffer, VkBuffer pDstBuffer, const VkBufferCopy& pRegion) :
+		srcBuffer(pSrcBuffer), dstBuffer(pDstBuffer), region(pRegion)
+	{
+	}
+
+	void play(CommandBuffer::ExecutionState& executionState)
+	{
+		Cast(srcBuffer)->copyTo(Cast(dstBuffer), region);
+	}
+
+private:
+	VkBuffer srcBuffer;
+	VkBuffer dstBuffer;
+	const VkBufferCopy region;
+};
+
 struct ImageToBufferCopy : public CommandBuffer::Command
 {
 	ImageToBufferCopy(VkImage pSrcImage, VkBuffer pDstBuffer, const VkBufferImageCopy& pRegion) :
@@ -486,7 +504,12 @@
 
 void CommandBuffer::copyBuffer(VkBuffer srcBuffer, VkBuffer dstBuffer, uint32_t regionCount, const VkBufferCopy* pRegions)
 {
-	UNIMPLEMENTED();
+	ASSERT(state == RECORDING);
+
+	for(uint32_t i = 0; i < regionCount; i++)
+	{
+		commands->push_back(std::make_unique<BufferToBufferCopy>(srcBuffer, dstBuffer, pRegions[i]));
+	}
 }
 
 void CommandBuffer::copyImage(VkImage srcImage, VkImageLayout srcImageLayout, VkImage dstImage, VkImageLayout dstImageLayout,