Fix multisampled color attachment sync (#349) (#350)

krfantasy · web-flow · commit 681c588e3b4f · 2023-07-24T20:43:47.000+02:00
* Fix multisampled color attachment sync (#349) * Update 10_Multisampling.md fix typo
diff --git a/code/30_multisampling.cpp b/code/30_multisampling.cpp
@@ -597,7 +597,7 @@ class HelloTriangleApplication {
         dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
         dependency.dstSubpass = 0;
         dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT;
-        dependency.srcAccessMask = VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
+        dependency.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
         dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT;
         dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
 
diff --git a/en/10_Multisampling.md b/en/10_Multisampling.md
@@ -196,6 +196,14 @@ Set the `pResolveAttachments` subpass struct member to point to the newly create
     ...
 ```
 
+Since we're reusing the multisampled color image, it's necessary to update the `srcAccessMask` of the `VkSubpassDependency`. This update ensures that any write operations to the color attachment are completed before subsequent ones begin, thus preventing write-after-write hazards that can lead to unstable rendering results:
+
+```c++
+    ...
+    dependency.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
+    ...
+```
+
 Now update render pass info struct with the new color attachment:
 
 ```c++
