From 08fc5342a92c57fdd9008e60f357b8baa80cd867 Mon Sep 17 00:00:00 2001
From: Joshua Ashton <joshua@froggi.es>
Date: Tue, 4 Feb 2020 21:36:31 +0000
Subject: [PATCH] [dxso] Initialize vPos in shaders if we have pixel fog

Fixes some fog related regressions since we deferred this
---
 src/dxso/dxso_compiler.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/dxso/dxso_compiler.cpp b/src/dxso/dxso_compiler.cpp
index e03ddc91..e12b05c8 100644
--- a/src/dxso/dxso_compiler.cpp
+++ b/src/dxso/dxso_compiler.cpp
@@ -3561,6 +3561,15 @@ void DxsoCompiler::emitControlFlowGenericLoop(
 
     this->emitInputSetup();
 
+    bool canUsePixelFog = m_programInfo.majorVersion() < 3;
+
+    if (canUsePixelFog) {
+      // Look up vPos so it gets initted.
+      DxsoRegister vPos;
+      vPos.id = DxsoRegisterId{ DxsoRegisterType::MiscType, DxsoMiscTypeIndices::MiscTypePosition };
+      auto vPosPtr = this->emitGetOperandPtr(vPos);
+    }
+
     if (m_ps.vPos.id != 0) {
       DxsoRegisterPointer fragCoord = this->emitRegisterPtr(
         "ps_frag_coord", DxsoScalarType::Float32, 4, 0,