I am trying to use the color binding created in subpass 0 as an input attachment to subpass 1. However, there is a problem that I cannot get through.
Currently, the problem is this: I am trying to clear attachment 0 at the beginning of a pass with VK_ATTACHMENT_LOAD_OP_CLEAR, but gives an error.
Cannot clear attachment 0 with invalid first layout VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL.
What seems strange to me, attachment 0 does not get the layout VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMALuntil subpass 1, where is the input attachment, while clarity should have happened when the layout was still VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL(AFAIK).
Now I tried to just continue working after a validation error, and an attachment of 0 makes it clear, which makes me even more insecure. Maybe I will just ignore the validation error, but something strange may happen that may cause problems later, so I don’t trust enough to just ignore it.
Here is the minimal code that will give an error:
VkAttachmentDescription attachments[1] {};
attachments[0].format = VK_FORMAT_R16G16B16A16_SFLOAT;
attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
attachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
attachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
attachments[0].initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
attachments[0].finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
VkAttachmentReference pass_0_ColorAttachments[1];
pass_0_ColorAttachments[0].attachment = 0;
pass_0_ColorAttachments[0].layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
VkAttachmentReference pass_1_InputAttachments[1];
pass_1_InputAttachments[0].attachment = 0;
pass_1_InputAttachments[0].layout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
VkSubpassDescription subpasses[2] {};
subpasses[0].colorAttachmentCount = 1;
subpasses[0].pColorAttachments = pass_0_ColorAttachments;
subpasses[0].pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
subpasses[1].inputAttachmentCount = 1;
subpasses[1].pInputAttachments = pass_1_InputAttachments;
subpasses[1].pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
VkSubpassDependency subpassDependancies[1] {};
subpassDependancies[0].srcSubpass = 0;
subpassDependancies[0].dstSubpass = 1;
subpassDependancies[0].srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
subpassDependancies[0].dstStageMask = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
subpassDependancies[0].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
subpassDependancies[0].dstAccessMask = VK_ACCESS_INPUT_ATTACHMENT_READ_BIT;
subpassDependancies[0].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;
VkRenderPassCreateInfo renderpassCreateInfo {};
renderpassCreateInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
renderpassCreateInfo.attachmentCount = 1;
renderpassCreateInfo.pAttachments = attachments;
renderpassCreateInfo.subpassCount = 2;
renderpassCreateInfo.pSubpasses = subpasses;
renderpassCreateInfo.dependencyCount = 1;
renderpassCreateInfo.pDependencies = subpassDependancies;
VkRenderPass renderPass;
vkCreateRenderPass(device, &renderpassCreateInfo, nullptr, &renderPass);
The next part is applicable only if it is impossible to indicate VK_ATTACHMENT_LOAD_OP_CLEARfor the attachment, which is used as a color attachment first, and in a later subpass as an input attachment (I see no reason why this would not be possible if the volcano does not carry out the work of each subband). So this is a kind of separate problem.
VK_ATTACHMENT_LOAD_OP_CLEAR vkCmdClearAttachments VK_ATTACHMENT_LOAD_OP_DONT_CARE .
vkCmdClearAttachments
, subpass :
VkClearAttachment clearAtts[] = {{VK_IMAGE_ASPECT_COLOR_BIT, 1, {0,0,0,0}}};
VkClearRect rect = {{{0,0}, {1,1}}, 0, 1};
vkCmdClearAttachments(vkCommandBuffer, 1, clearAtts, 1, &rect);
{1,1}, , ,