From cb240560df0653fe3fef3431e6997dd47cc2c3cf Mon Sep 17 00:00:00 2001
From: goldislead <69987043+goldislead@users.noreply.github.com>
Date: Tue, 4 Aug 2026 16:32:00 -0700
Subject: [PATCH] [Vulkan] Fix 2x MSAA alpha-to-coverage sample layout

Co-authored-by: Herman S. <429230+has207@users.noreply.github.com>
---
 src/xenia/gpu/spirv_shader_translator_rb.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/xenia/gpu/spirv_shader_translator_rb.cc b/src/xenia/gpu/spirv_shader_translator_rb.cc
index f2be2b72b..fb058ad88 100644
--- a/src/xenia/gpu/spirv_shader_translator_rb.cc
+++ b/src/xenia/gpu/spirv_shader_translator_rb.cc
@@ -4401,8 +4401,11 @@ void SpirvShaderTranslator::FSI_AlphaToMask() {
     FSI_AlphaToMaskSample(false, 1, 1.0f, threshold_offset, 1.0f / 8.0f, alpha,
                           coverage_2x);
   } else {
-    // FBO: Account for native 2x vs 2x-as-4x sample mapping.
-    if (native_2x_msaa_no_attachments_) {
+    // FBO: Account for native 2x vs 2x-as-4x sample mapping. This epilogue only
+    // runs when there is a color attachment (sample mask output), so whether 2x
+    // is native must be taken from the capability with attachments, matching
+    // the choice made for the host pipeline.
+    if (native_2x_msaa_with_attachments_) {
       // Native 2x: D3D10.1+ standard - top is 1, bottom is 0.
       FSI_AlphaToMaskSample(true, 1, 0.5f, threshold_offset, 1.0f / 8.0f, alpha,
                             coverage_2x);