From 8dc3653ac9ec07040c8bcd0748c8040cf831d632 Mon Sep 17 00:00:00 2001
From: Jules Blok <jules.blok@gmail.com>
Date: Wed, 17 Dec 2014 23:44:05 +0100
Subject: [PATCH] VideoCommon: Don't pass structs between shader stages when
 geometry shaders are unsupported.

---
 Source/Core/VideoCommon/PixelShaderGen.cpp  | 39 ++++++++++++++-------
 Source/Core/VideoCommon/VertexShaderGen.cpp | 30 +++++++++++++++-
 2 files changed, 56 insertions(+), 13 deletions(-)

diff --git a/Source/Core/VideoCommon/PixelShaderGen.cpp b/Source/Core/VideoCommon/PixelShaderGen.cpp
index 8557f9e98b..77f24d115c 100644
--- a/Source/Core/VideoCommon/PixelShaderGen.cpp
+++ b/Source/Core/VideoCommon/PixelShaderGen.cpp
@@ -329,27 +329,42 @@ static inline void GeneratePixelShader(T& out, DSTALPHA_MODE dstAlphaMode, API_T
 		}
 		else
 		{
-			out.Write("centroid in VS_OUTPUT o;\n");
+			out.Write("centroid in float4 colors_02;\n");
+			out.Write("centroid in float4 colors_12;\n");
+			// compute window position if needed because binding semantic WPOS is not widely supported
+			// Let's set up attributes
+			for (unsigned int i = 0; i < numTexgen; ++i)
+			{
+				out.Write("centroid in float3 uv%d;\n", i);
+			}
+			out.Write("centroid in float4 clipPos;\n");
+			if (g_ActiveConfig.bEnablePixelLighting)
+			{
+				out.Write("centroid in float4 Normal;\n");
+			}
 		}
 
 		out.Write("void main()\n{\n");
 
-		// compute window position if needed because binding semantic WPOS is not widely supported
-		// Let's set up attributes
-		for (unsigned int i = 0; i < numTexgen; ++i)
+		if (g_ActiveConfig.backend_info.bSupportsGeometryShaders)
 		{
-			out.Write("\tfloat3 uv%d = o.tex%d;\n", i, i);
-		}
-		out.Write("\tfloat4 clipPos = o.clipPos;\n");
-		if (g_ActiveConfig.bEnablePixelLighting)
-		{
-			out.Write("\tfloat4 Normal = o.Normal;\n");
+			// compute window position if needed because binding semantic WPOS is not widely supported
+			// Let's set up attributes
+			for (unsigned int i = 0; i < numTexgen; ++i)
+			{
+				out.Write("\tfloat3 uv%d = o.tex%d;\n", i, i);
+			}
+			out.Write("\tfloat4 clipPos = o.clipPos;\n");
+			if (g_ActiveConfig.bEnablePixelLighting)
+			{
+				out.Write("\tfloat4 Normal = o.Normal;\n");
+			}
 		}
 
 		// On Mali, global variables must be initialized as constants.
 		// This is why we initialize these variables locally instead.
-		out.Write("\tfloat4 colors_0 = o.colors_0;\n");
-		out.Write("\tfloat4 colors_1 = o.colors_1;\n");
+		out.Write("\tfloat4 colors_0 = %s;\n", g_ActiveConfig.backend_info.bSupportsGeometryShaders ? "o.colors_0" : "colors_02");
+		out.Write("\tfloat4 colors_1 = %s;\n", g_ActiveConfig.backend_info.bSupportsGeometryShaders ? "o.colors_1" : "colors_12");
 
 		out.Write("\tfloat4 rawpos = gl_FragCoord;\n");
 	}
diff --git a/Source/Core/VideoCommon/VertexShaderGen.cpp b/Source/Core/VideoCommon/VertexShaderGen.cpp
index bd033967ee..123f137ff2 100644
--- a/Source/Core/VideoCommon/VertexShaderGen.cpp
+++ b/Source/Core/VideoCommon/VertexShaderGen.cpp
@@ -80,10 +80,25 @@ static inline void GenerateVertexShader(T& out, u32 components, API_TYPE api_typ
 		}
 		else
 		{
-			out.Write("centroid out VS_OUTPUT o; \n");
+			// Let's set up attributes
+			for (size_t i = 0; i < 8; ++i)
+			{
+				if (i < xfmem.numTexGen.numTexGens)
+				{
+					out.Write("centroid out float3 uv%d;\n", i);
+				}
+			}
+			out.Write("centroid out float4 clipPos;\n");
+			if (g_ActiveConfig.bEnablePixelLighting)
+				out.Write("centroid out float4 Normal;\n");
+			out.Write("centroid out float4 colors_02;\n");
+			out.Write("centroid out float4 colors_12;\n");
 		}
 
 		out.Write("void main()\n{\n");
+
+		if (!g_ActiveConfig.backend_info.bSupportsGeometryShaders)
+			out.Write("VS_OUTPUT o;\n");
 	}
 	else // D3D
 	{
@@ -369,6 +384,19 @@ static inline void GenerateVertexShader(T& out, u32 components, API_TYPE api_typ
 
 	if (api_type == API_OPENGL)
 	{
+		if (!g_ActiveConfig.backend_info.bSupportsGeometryShaders)
+		{
+			// TODO: Pass structs between shader stages even if geometry shaders
+			// are not supported, however that will break GL 3.0 and 3.1 support.
+			for (unsigned int i = 0; i < xfmem.numTexGen.numTexGens; ++i)
+				out.Write("uv%d.xyz = o.tex%d;\n", i, i);
+			out.Write("clipPos = o.clipPos;\n");
+			if (g_ActiveConfig.bEnablePixelLighting)
+				out.Write("Normal = o.Normal;\n");
+			out.Write("colors_02 = o.colors_0;\n");
+			out.Write("colors_12 = o.colors_1;\n");
+		}
+
 		out.Write("gl_Position = o.pos;\n");
 	}
 	else // D3D