Proper image layout for descriptor image infos (instead of always GENERAL), code cleanup, comments

texture/texture.cpp

@@ -45,7 +45,6 @@ public:
 		VkImageLayout imageLayout;
 		VkDeviceMemory deviceMemory;
 		VkImageView view;
-		VkDescriptorImageInfo descriptor;
 		uint32_t width, height;
 		uint32_t mipLevels;
 	} texture;
@@ -474,7 +473,6 @@ public:
 		// are abstracted by image views containing additional
 		// information and sub resource ranges
 		VkImageViewCreateInfo view = vkTools::initializers::imageViewCreateInfo();
-		view.image = VK_NULL_HANDLE;
 		view.viewType = VK_IMAGE_VIEW_TYPE_2D;
 		view.format = format;
 		view.components = { VK_COMPONENT_SWIZZLE_R, VK_COMPONENT_SWIZZLE_G, VK_COMPONENT_SWIZZLE_B, VK_COMPONENT_SWIZZLE_A };
@@ -487,13 +485,9 @@ public:
 		// Linear tiling usually won't support mip maps
 		// Only set mip map count if optimal tiling is used
 		view.subresourceRange.levelCount = (useStaging) ? texture.mipLevels : 1;
+		// The view will be based on the texture's image
 		view.image = texture.image;
 		VK_CHECK_RESULT(vkCreateImageView(device, &view, nullptr, &texture.view));
-
-		// Fill image descriptor image info that can be used during the descriptor set setup
-		texture.descriptor.imageLayout = VK_IMAGE_LAYOUT_GENERAL;
-		texture.descriptor.imageView = texture.view;
-		texture.descriptor.sampler = texture.sampler;
 	}
 
 	// Free all Vulkan resources used a texture object
@@ -700,6 +694,12 @@ public:
 
 		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));
 
+		// Setup a descriptor image info for the current texture to be used as a combined image sampler
+		VkDescriptorImageInfo textureDescriptor;
+		textureDescriptor.imageView = texture.view;				// The image's view (images are never directly accessed by the shader, but rather through views defining subresources)
+		textureDescriptor.sampler = texture.sampler;			//	The sampler (Telling the pipeline how to sample the texture, including repeat, border, etc.)
+		textureDescriptor.imageLayout = texture.imageLayout;	//	The current layout of the image (Note: Should always fit the actual use, e.g. shader read)
+
 		std::vector<VkWriteDescriptorSet> writeDescriptorSets =
 		{
 			// Binding 0 : Vertex shader uniform buffer
@@ -709,11 +709,12 @@ public:
 				0, 
 				&uniformBufferVS.descriptor),
 			// Binding 1 : Fragment shader texture sampler
+			//	Fragment shader: layout (binding = 1) uniform sampler2D samplerColor;
 			vkTools::initializers::writeDescriptorSet(
 				descriptorSet, 				
-				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 
-				1, 
-				&texture.descriptor)
+				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,			// The descriptor set will use a combined image sampler (sampler and image could be split)
+				1,													// Shader binding point 1
+				&textureDescriptor)								// Pointer to the descriptor image for our texture
 		};
 
 		vkUpdateDescriptorSets(device, static_cast<uint32_t>(writeDescriptorSets.size()), writeDescriptorSets.data(), 0, NULL);

texturearray/texturearray.cpp

@@ -489,11 +489,11 @@ public:
 		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));
 
 		// Image descriptor for the texture array
-		VkDescriptorImageInfo texArrayDescriptor =
+		VkDescriptorImageInfo textureDescriptor =
 			vkTools::initializers::descriptorImageInfo(
 				textureArray.sampler,
 				textureArray.view,
-				VK_IMAGE_LAYOUT_GENERAL);
+				textureArray.imageLayout);
 
 		std::vector<VkWriteDescriptorSet> writeDescriptorSets =
 		{
@@ -508,7 +508,7 @@ public:
 				descriptorSet,
 				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
 				1,
-				&texArrayDescriptor)
+				&textureDescriptor)
 		};
 
 		vkUpdateDescriptorSets(device, writeDescriptorSets.size(), writeDescriptorSets.data(), 0, NULL);

texturecubemap/texturecubemap.cpp

@@ -470,11 +470,11 @@ public:
 	void setupDescriptorSets()
 	{
 		// Image descriptor for the cube map texture
-		VkDescriptorImageInfo cubeMapDescriptor =
+		VkDescriptorImageInfo textureDescriptor =
 			vkTools::initializers::descriptorImageInfo(
 				cubeMap.sampler,
 				cubeMap.view,
-				VK_IMAGE_LAYOUT_GENERAL);
+				cubeMap.imageLayout);
 
 		VkDescriptorSetAllocateInfo allocInfo =
 			vkTools::initializers::descriptorSetAllocateInfo(
@@ -498,7 +498,7 @@ public:
 				descriptorSets.object, 
 				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 
 				1, 
-				&cubeMapDescriptor)
+				&textureDescriptor)
 		};
 		vkUpdateDescriptorSets(device, writeDescriptorSets.size(), writeDescriptorSets.data(), 0, NULL);
 
@@ -518,7 +518,7 @@ public:
 				descriptorSets.skybox,
 				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
 				1,
-				&cubeMapDescriptor)
+				&textureDescriptor)
 		};
 		vkUpdateDescriptorSets(device, writeDescriptorSets.size(), writeDescriptorSets.data(), 0, NULL);
 	}

texturemipmapgen/texturemipmapgen.cpp

@@ -547,12 +547,16 @@ public:
 			&uniformBufferVS.descriptor));
 
 		// Binding 1: Sampled image
-		VkDescriptorImageInfo texDescriptor = vkTools::initializers::descriptorImageInfo(VK_NULL_HANDLE, texture.view, VK_IMAGE_LAYOUT_GENERAL);
+		VkDescriptorImageInfo textureDescriptor = 
+			vkTools::initializers::descriptorImageInfo(
+				VK_NULL_HANDLE,				 
+				texture.view, 
+				texture.imageLayout);
 		writeDescriptorSets.push_back(vkTools::initializers::writeDescriptorSet(
 			descriptorSet,
 			VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
 			1,
-			&texDescriptor));
+			&textureDescriptor));
 
 		// Binding 2: Sampler array
 		std::vector<VkDescriptorImageInfo> samplerDescriptors;