From 5560a72fc8eda64e17ab15469f055edd36cc6045 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix=20Poisot?= <felix@lhfblc.fr>
Date: Fri, 12 Jun 2026 17:37:29 +0000
Subject: [PATCH] render/vulkan: let vkRenderPass handle blend buffer layout
 transitions

---
 render/vulkan/pass.c     | 33 ++++-----------------------------
 render/vulkan/renderer.c |  2 +-
 2 files changed, 5 insertions(+), 30 deletions(-)

diff --git a/render/vulkan/pass.c b/render/vulkan/pass.c
index 38be3320b..2e98b268a 100644
--- a/render/vulkan/pass.c
+++ b/render/vulkan/pass.c
@@ -428,35 +428,6 @@ static bool render_pass_submit(struct wlr_render_pass *wlr_pass) {
 		pass->render_buffer_out->transitioned = true;
 	}
 
-	if (pass->two_pass) {
-		// On the first frame the clear render pass transitions the blend
-		// image from undefined and we just mark it transitioned. On every
-		// frame after, the previous frame left it read-only, so we change
-		// it back to a color attachment before the render pass starts
-		if (render_buffer->two_pass.blend_transitioned) {
-			VkImageMemoryBarrier blend_acq_barrier = {
-				.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,
-				.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
-				.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
-				.image = render_buffer->two_pass.blend_image,
-				.oldLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
-				.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
-				.srcAccessMask = VK_ACCESS_SHADER_READ_BIT,
-				.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT,
-				.subresourceRange = {
-					.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT,
-					.layerCount = 1,
-					.levelCount = 1,
-				},
-			};
-			vkCmdPipelineBarrier(stage_cb->vk, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT,
-				VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT,
-				0, 0, NULL, 0, NULL, 1, &blend_acq_barrier);
-		} else {
-			render_buffer->two_pass.blend_transitioned = true;
-		}
-	}
-
 	// acquire render buffer before rendering
 	acquire_barriers[idx] = (VkImageMemoryBarrier){
 		.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,
@@ -602,6 +573,10 @@ static bool render_pass_submit(struct wlr_render_pass *wlr_pass) {
 		goto error;
 	}
 
+	if (pass->two_pass) {
+		render_buffer->two_pass.blend_transitioned = true;
+	}
+
 	free(render_wait);
 
 	vulkan_stage_mark_submit(renderer, render_timeline_point);
diff --git a/render/vulkan/renderer.c b/render/vulkan/renderer.c
index 44f4d39d8..e12a43891 100644
--- a/render/vulkan/renderer.c
+++ b/render/vulkan/renderer.c
@@ -2485,7 +2485,7 @@ static struct wlr_vk_render_format_setup *find_or_create_render_setup(
 				.storeOp = VK_ATTACHMENT_STORE_OP_STORE,
 				.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE,
 				.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE,
-				.initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
+				.initialLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
 				.finalLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
 			},
 			{