From b56d0da86d3a8ea58850989a472e0008ee53763c Mon Sep 17 00:00:00 2001
From: ParantezTech <12572227+par274@users.noreply.github.com>
Date: Mon, 5 Oct 2026 18:38:07 +0300
Subject: [PATCH] [ShaderCompiler] Reserve a clip plane for position exports

---
 .../Gen5SpirvTranslator.cs                               | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/SharpEmu.ShaderCompiler.Vulkan/Gen5SpirvTranslator.cs b/src/SharpEmu.ShaderCompiler.Vulkan/Gen5SpirvTranslator.cs
index d0e5737..0499223 100644
--- a/src/SharpEmu.ShaderCompiler.Vulkan/Gen5SpirvTranslator.cs
+++ b/src/SharpEmu.ShaderCompiler.Vulkan/Gen5SpirvTranslator.cs
@@ -185,6 +185,7 @@ public static partial class Gen5SpirvTranslator
         private uint _layerOutput;
         private uint _viewportIndexOutput;
         private uint _clipDistanceCount;
+        private uint _invalidPositionClipDistance = uint.MaxValue;
         private uint _cullDistanceCount;
         private uint _vertexIndexInput;
         private uint _instanceIndexInput;
@@ -6696,6 +6697,14 @@ public static partial class Gen5SpirvTranslator
                 }
             }
 
+            if (_request.SupportsClipDistance && clipCount + cullCount < 8 &&
+                _request.Program.Instructions.Any(static instruction =>
+                    instruction.Control is Gen5ExportControl { Target: 12, EnableMask: not 0 }))
+            {
+                // Use a separate plane so auxiliary position exports keep their own distances.
+                _invalidPositionClipDistance = clipCount++;
+            }
+
             if (needPointSize)
             {
                 _pointSizeOutput = DeclareBuiltInOutput(