Can someone please help explain something related to image layout

[TheFearlessHobbit]

Hello, with Vulkan 1.3, we can now do dynamic rendering instead of creating a Render Pass object and framebuffers. I decided to give it a go, but I had to do the following before I record commands into my command buffers.

VkImageMemoryBarrier imageMemoryBarrier{};
		imageMemoryBarrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
		imageMemoryBarrier.pNext = nullptr;
		imageMemoryBarrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		imageMemoryBarrier.oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		imageMemoryBarrier.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
		imageMemoryBarrier.image = swapchainImages[i];
		imageMemoryBarrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		imageMemoryBarrier.subresourceRange.baseMipLevel = 0;
		imageMemoryBarrier.subresourceRange.levelCount = 1;
		imageMemoryBarrier.subresourceRange.baseArrayLayer = 0;
		imageMemoryBarrier.subresourceRange.layerCount = 1;

can someone help me understand why I had to do that? What exactly is an image layout? Thanks.

[krOoze]

I don’t understand the question. It is the same thing as it was before 1.3.

Image layout is image layout. It is selfexplanatory. Depth buffer needs depth layout. Color buffer needs color layout. Presentation needs presentation layout. And so on. It is simply the state\mode of the image it has to be in for a given usage.

Drivers can use this information however they wish (ranging from doing nothing with this, to making some write access to the image). Nevertheless, it is always formally required to do when using the API.

Assumably you had to do it because your image had been freshly created, and you needed to use it as a color framebuffer.

[TheFearlessHobbit]

It is simply the state\mode of the image it has to be in for a given usage

I come from OpenGL so that’s a new thing for me, thanks.