Small fixes merge from v2.

Author: adam-sawicki-a

src/VulkanSample.cpp

@@ -288,7 +288,7 @@ static void CreateMesh()
     vbInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
     vbInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
     VmaMemoryRequirements vbMemReq = {};
-    vbMemReq.usage = VMA_MEMORY_USAGE_CPU_TO_GPU;
+    vbMemReq.usage = VMA_MEMORY_USAGE_CPU_ONLY;
     VkMappedMemoryRange stagingVertexBufferMem;
     VkBuffer stagingVertexBuffer = VK_NULL_HANDLE;
     ERR_GUARD_VULKAN( vmaCreateBuffer(g_hAllocator, &vbInfo, &vbMemReq, &stagingVertexBuffer, &stagingVertexBufferMem, nullptr) );
@@ -298,6 +298,8 @@ static void CreateMesh()
     memcpy(pVbData, vertices, vertexBufferSize);
     vmaUnmapMemory(g_hAllocator, &stagingVertexBufferMem);
 
+    // No need to flush stagingVertexBuffer memory because CPU_ONLY memory is always HOST_COHERENT.
+
     vbInfo.usage = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
     vbMemReq.usage = VMA_MEMORY_USAGE_GPU_ONLY;
     ERR_GUARD_VULKAN( vmaCreateBuffer(g_hAllocator, &vbInfo, &vbMemReq, &g_hVertexBuffer, nullptr, nullptr) );
@@ -309,7 +311,7 @@ static void CreateMesh()
     ibInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
     ibInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
     VmaMemoryRequirements ibMemReq = {};
-    ibMemReq.usage = VMA_MEMORY_USAGE_CPU_TO_GPU;
+    ibMemReq.usage = VMA_MEMORY_USAGE_CPU_ONLY;
     VkMappedMemoryRange stagingIndexBufferMem;
     VkBuffer stagingIndexBuffer = VK_NULL_HANDLE;
     ERR_GUARD_VULKAN( vmaCreateBuffer(g_hAllocator, &ibInfo, &ibMemReq, &stagingIndexBuffer, &stagingIndexBufferMem, nullptr) );
@@ -319,6 +321,8 @@ static void CreateMesh()
     memcpy(pIbData, indices, indexBufferSize);
     vmaUnmapMemory(g_hAllocator, &stagingIndexBufferMem);
 
+    // No need to flush stagingIndexBuffer memory because CPU_ONLY memory is always HOST_COHERENT.
+
     ibInfo.usage = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_INDEX_BUFFER_BIT;
     ibMemReq.usage = VMA_MEMORY_USAGE_GPU_ONLY;
     ERR_GUARD_VULKAN( vmaCreateBuffer(g_hAllocator, &ibInfo, &ibMemReq, &g_hIndexBuffer, nullptr, nullptr) );
@@ -469,7 +473,7 @@ static void CreateTexture(uint32_t sizeX, uint32_t sizeY)
     stagingImageInfo.samples = VK_SAMPLE_COUNT_1_BIT;
     stagingImageInfo.flags = 0;
     VmaMemoryRequirements stagingImageMemReq = {};
-    stagingImageMemReq.usage = VMA_MEMORY_USAGE_CPU_TO_GPU;
+    stagingImageMemReq.usage = VMA_MEMORY_USAGE_CPU_ONLY;
     VkImage stagingImage = VK_NULL_HANDLE;
     VkMappedMemoryRange stagingImageMem;
     ERR_GUARD_VULKAN( vmaCreateImage(g_hAllocator, &stagingImageInfo, &stagingImageMemReq, &stagingImage, &stagingImageMem, nullptr) );
@@ -504,6 +508,8 @@ static void CreateTexture(uint32_t sizeX, uint32_t sizeY)
 
     vmaUnmapMemory(g_hAllocator, &stagingImageMem);
 
+    // No need to flush stagingImage memory because CPU_ONLY memory is always HOST_COHERENT.
+
     VkImageCreateInfo imageInfo = { VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO };
     imageInfo.imageType = VK_IMAGE_TYPE_2D;
     imageInfo.extent.width = sizeX;