ShaderGen: Omit some unused varyings when possible

Removes the clipPos varying unless slow-depth is used, and the
clipDistance varyings if geometry shaders are not used.

1 files changed, 17 insertions, 10 deletions

diff --git a/Source/Core/VideoCommon/PixelShaderGen.cpp b/Source/Core/VideoCommon/PixelShaderGen.cpp
index 936dd8e937..ce42363d19 100644
--- a/Source/Core/VideoCommon/PixelShaderGen.cpp
+++ b/Source/Core/VideoCommon/PixelShaderGen.cpp
@@ -351,7 +351,7 @@ void ClearUnusedPixelShaderUidBits(APIType ApiType, const ShaderHostConfig& host
 }
 
 void WritePixelShaderCommonHeader(ShaderCode& out, APIType ApiType, u32 num_texgens,
-                                  bool per_pixel_lighting, bool bounding_box)
+                                  const ShaderHostConfig& host_config, bool bounding_box)
 {
   // dot product for integer vectors
   out.Write("int idot(int3 x, int3 y)\n"
@@ -430,7 +430,7 @@ void WritePixelShaderCommonHeader(ShaderCode& out, APIType ApiType, u32 num_texg
             "#define bpmem_tevorder(i) (bpmem_pack2[(i)].x)\n"
             "#define bpmem_tevksel(i) (bpmem_pack2[(i)].y)\n\n");
 
-  if (per_pixel_lighting)
+  if (host_config.per_pixel_lighting)
   {
     out.Write("%s", s_lighting_struct);
 
@@ -458,7 +458,7 @@ void WritePixelShaderCommonHeader(ShaderCode& out, APIType ApiType, u32 num_texg
   }
 
   out.Write("struct VS_OUTPUT {\n");
-  GenerateVSOutputMembers(out, ApiType, num_texgens, per_pixel_lighting, "");
+  GenerateVSOutputMembers(out, ApiType, num_texgens, host_config, "");
   out.Write("};\n");
 }
 
@@ -491,7 +491,7 @@ ShaderCode GeneratePixelShaderCode(APIType ApiType, const ShaderHostConfig& host
             uid_data->genMode_numindstages);
 
   // Stuff that is shared between ubershaders and pixelgen.
-  WritePixelShaderCommonHeader(out, ApiType, uid_data->genMode_numtexgens, per_pixel_lighting,
+  WritePixelShaderCommonHeader(out, ApiType, uid_data->genMode_numtexgens, host_config,
                                uid_data->bounding_box);
 
   if (uid_data->forced_early_z && g_ActiveConfig.backend_info.bSupportsEarlyZ)
@@ -591,7 +591,7 @@ ShaderCode GeneratePixelShaderCode(APIType ApiType, const ShaderHostConfig& host
     if (host_config.backend_geometry_shaders || ApiType == APIType::Vulkan)
     {
       out.Write("VARYING_LOCATION(0) in VertexData {\n");
-      GenerateVSOutputMembers(out, ApiType, uid_data->genMode_numtexgens, per_pixel_lighting,
+      GenerateVSOutputMembers(out, ApiType, uid_data->genMode_numtexgens, host_config,
                               GetInterpolationQualifier(msaa, ssaa, true, true));
 
       if (stereo)
@@ -609,7 +609,8 @@ ShaderCode GeneratePixelShaderCode(APIType ApiType, const ShaderHostConfig& host
       {
         out.Write("%s in float3 tex%d;\n", GetInterpolationQualifier(msaa, ssaa), i);
       }
-      out.Write("%s in float4 clipPos;\n", GetInterpolationQualifier(msaa, ssaa));
+      if (!host_config.fast_depth_calc)
+        out.Write("%s in float4 clipPos;\n", GetInterpolationQualifier(msaa, ssaa));
       if (per_pixel_lighting)
       {
         out.Write("%s in float3 Normal;\n", GetInterpolationQualifier(msaa, ssaa));
@@ -646,8 +647,11 @@ ShaderCode GeneratePixelShaderCode(APIType ApiType, const ShaderHostConfig& host
     for (unsigned int i = 0; i < uid_data->genMode_numtexgens; ++i)
       out.Write(",\n  in %s float3 tex%d : TEXCOORD%d", GetInterpolationQualifier(msaa, ssaa), i,
                 i);
-    out.Write(",\n  in %s float4 clipPos : TEXCOORD%d", GetInterpolationQualifier(msaa, ssaa),
-              uid_data->genMode_numtexgens);
+    if (!host_config.fast_depth_calc)
+    {
+      out.Write(",\n  in %s float4 clipPos : TEXCOORD%d", GetInterpolationQualifier(msaa, ssaa),
+                uid_data->genMode_numtexgens);
+    }
     if (per_pixel_lighting)
     {
       out.Write(",\n  in %s float3 Normal : TEXCOORD%d", GetInterpolationQualifier(msaa, ssaa),
@@ -655,8 +659,11 @@ ShaderCode GeneratePixelShaderCode(APIType ApiType, const ShaderHostConfig& host
       out.Write(",\n  in %s float3 WorldPos : TEXCOORD%d", GetInterpolationQualifier(msaa, ssaa),
                 uid_data->genMode_numtexgens + 2);
     }
-    out.Write(",\n  in float clipDist0 : SV_ClipDistance0\n");
-    out.Write(",\n  in float clipDist1 : SV_ClipDistance1\n");
+    if (host_config.backend_geometry_shaders)
+    {
+      out.Write(",\n  in float clipDist0 : SV_ClipDistance0\n");
+      out.Write(",\n  in float clipDist1 : SV_ClipDistance1\n");
+    }
     if (stereo)
       out.Write(",\n  in uint layer : SV_RenderTargetArrayIndex\n");
     out.Write("        ) {\n");