Transition Image Layout

switch (oldImageLayout)
			{
			case VK_IMAGE_LAYOUT_UNDEFINED:
				// Image layout is undefined (or does not matter)
				// Only valid as initial layout
				// No flags required, listed only for completeness
				imageMemoryBarrier.srcAccessMask = 0;
				break;

			case VK_IMAGE_LAYOUT_PREINITIALIZED:
				// Image is preinitialized
				// Only valid as initial layout for linear images, preserves memory contents
				// Make sure host writes have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_HOST_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL:
				// Image is a color attachment
				// Make sure any writes to the color buffer have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL:
				// Image is a depth/stencil attachment
				// Make sure any writes to the depth/stencil buffer have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL:
				// Image is a transfer source
				// Make sure any reads from the image have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
				break;

			case VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL:
				// Image is a transfer destination
				// Make sure any writes to the image have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL:
				// Image is read by a shader
				// Make sure any shader reads from the image have been finished
				imageMemoryBarrier.srcAccessMask = VK_ACCESS_SHADER_READ_BIT;
				break;
			default:
				// Other source layouts aren't handled (yet)
				break;
			}

			// Target layouts (new)
			// Destination access mask controls the dependency for the new image layout
			switch (newImageLayout)
			{
			case VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL:
				// Image will be used as a transfer destination
				// Make sure any writes to the image have been finished
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL:
				// Image will be used as a transfer source
				// Make sure any reads from the image have been finished
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
				break;

			case VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL:
				// Image will be used as a color attachment
				// Make sure any writes to the color buffer have been finished
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL:
				// Image layout will be used as a depth/stencil attachment
				// Make sure any writes to depth/stencil buffer have been finished
				imageMemoryBarrier.dstAccessMask = imageMemoryBarrier.dstAccessMask | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
				break;

			case VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL:
				// Image will be read in a shader (sampler, input attachment)
				// Make sure any writes to the image have been finished
				if (imageMemoryBarrier.srcAccessMask == 0)
				{
					imageMemoryBarrier.srcAccessMask = VK_ACCESS_HOST_WRITE_BIT | VK_ACCESS_TRANSFER_WRITE_BIT;
				}
				imageMemoryBarrier.dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
				break;
			default:
				// Other source layouts aren't handled (yet)
				break;
			}