UberShaderPixel: Return fixed-point values from selectTexCoord

This change should have no behavioral differences itself, but allows for changing the behavior of out of bounds tex coord indices more easily in the next commit.  Without this change, returning tex0 for out of bounds cases and then applying the fixed-point logic would use the wrong tex dimension info (tex0 with I_TEXDIMS[1] or such), which is inaccurate.

1 files changed, 32 insertions, 41 deletions

diff --git a/Source/Core/VideoCommon/UberShaderPixel.cpp b/Source/Core/VideoCommon/UberShaderPixel.cpp
index f3a1fe2a4b..574b089a7c 100644
--- a/Source/Core/VideoCommon/UberShaderPixel.cpp
+++ b/Source/Core/VideoCommon/UberShaderPixel.cpp
@@ -150,17 +150,10 @@ ShaderCode GenPixelShader(APIType ApiType, const ShaderHostConfig& host_config,
   // Uniform index -> texture coordinates
   if (numTexgen > 0)
   {
-    if (ApiType != APIType::D3D)
-    {
-      out.Write("float3 selectTexCoord(uint index) {{\n");
-    }
-    else
-    {
-      out.Write("float3 selectTexCoord(uint index");
-      for (u32 i = 0; i < numTexgen; i++)
-        out.Write(", float3 tex{}", i);
-      out.Write(") {{\n");
-    }
+    out.Write("int2 selectTexCoord(uint index");
+    for (u32 i = 0; i < numTexgen; i++)
+      out.Write(", int2 fixpoint_uv{}", i);
+    out.Write(") {{\n");
 
     if (ApiType == APIType::D3D)
     {
@@ -168,11 +161,11 @@ ShaderCode GenPixelShader(APIType ApiType, const ShaderHostConfig& host_config,
       for (u32 i = 0; i < numTexgen; i++)
       {
         out.Write("  case {}u:\n"
-                  "    return tex{};\n",
+                  "    return fixpoint_uv{};\n",
                   i, i);
       }
       out.Write("  default:\n"
-                "    return float3(0.0, 0.0, 0.0);\n"
+                "    return int2(0, 0);\n"
                 "  }}\n");
     }
     else
@@ -182,16 +175,16 @@ ShaderCode GenPixelShader(APIType ApiType, const ShaderHostConfig& host_config,
       if (numTexgen > 2)
         out.Write("    if (index < 2u) {{\n");
       if (numTexgen > 1)
-        out.Write("      return (index == 0u) ? tex0 : tex1;\n");
+        out.Write("      return (index == 0u) ? fixpoint_uv0 : fixpoint_uv1;\n");
       else
-        out.Write("      return (index == 0u) ? tex0 : float3(0.0, 0.0, 0.0);\n");
+        out.Write("      return (index == 0u) ? fixpoint_uv0 : int2(0, 0);\n");
       if (numTexgen > 2)
       {
         out.Write("    }} else {{\n");  // >= 2
         if (numTexgen > 3)
-          out.Write("      return (index == 2u) ? tex2 : tex3;\n");
+          out.Write("      return (index == 2u) ? fixpoint_uv2 : fixpoint_uv3;\n");
         else
-          out.Write("      return (index == 2u) ? tex2 : float3(0.0, 0.0, 0.0);\n");
+          out.Write("      return (index == 2u) ? fixpoint_uv2 : int2(0, 0);\n");
         out.Write("    }}\n");
       }
       if (numTexgen > 4)
@@ -200,16 +193,16 @@ ShaderCode GenPixelShader(APIType ApiType, const ShaderHostConfig& host_config,
         if (numTexgen > 6)
           out.Write("    if (index < 6u) {{\n");
         if (numTexgen > 5)
-          out.Write("      return (index == 4u) ? tex4 : tex5;\n");
+          out.Write("      return (index == 4u) ? fixpoint_uv4 : fixpoint_uv5;\n");
         else
-          out.Write("      return (index == 4u) ? tex4 : float3(0.0, 0.0, 0.0);\n");
+          out.Write("      return (index == 4u) ? fixpoint_uv4 : int2(0, 0);\n");
         if (numTexgen > 6)
         {
           out.Write("    }} else {{\n");  // >= 6 <= 8
           if (numTexgen > 7)
-            out.Write("      return (index == 6u) ? tex6 : tex7;\n");
+            out.Write("      return (index == 6u) ? fixpoint_uv6 : fixpoint_uv7;\n");
           else
-            out.Write("      return (index == 6u) ? tex6 : float3(0.0, 0.0, 0.0);\n");
+            out.Write("      return (index == 6u) ? fixpoint_uv6 : int2(0, 0);\n");
           out.Write("    }}\n");
         }
         out.Write("  }}\n");
@@ -293,9 +286,7 @@ ShaderCode GenPixelShader(APIType ApiType, const ShaderHostConfig& host_config,
               "  {{\n"
               "    uint texcoord = bitfieldExtract(iref, 0, 3);\n"
               "    uint texmap = bitfieldExtract(iref, 8, 3);\n"
-              "    float3 uv = getTexCoord(texcoord);\n"
-              "    int2 fixedPoint_uv = int2((uv.z == 0.0 ? uv.xy : (uv.xy / uv.z)) * " I_TEXDIMS
-              "[texcoord].zw);\n"
+              "    int2 fixedPoint_uv = getTexCoord(texcoord);\n"
               "\n"
               "    if (({} & 1u) == 0u)\n"
               "      fixedPoint_uv = fixedPoint_uv >> " I_INDTEXSCALE "[{} >> 1].xy;\n"
@@ -666,21 +657,14 @@ ShaderCode GenPixelShader(APIType ApiType, const ShaderHostConfig& host_config,
         "\n");
   }
 
-  // Since the texture coodinate variables aren't global, we need to pass
-  // them to the select function in D3D.
+  // Since the fixed-point texture coodinate variables aren't global, we need to pass
+  // them to the select function.  This applies to all backends.
   if (numTexgen > 0)
   {
-    if (ApiType != APIType::D3D)
-    {
-      out.Write("#define getTexCoord(index) selectTexCoord((index))\n\n");
-    }
-    else
-    {
-      out.Write("#define getTexCoord(index) selectTexCoord((index)");
-      for (u32 i = 0; i < numTexgen; i++)
-        out.Write(", tex{}", i);
-      out.Write(")\n\n");
-    }
+    out.Write("#define getTexCoord(index) selectTexCoord((index)");
+    for (u32 i = 0; i < numTexgen; i++)
+      out.Write(", fixpoint_uv{}", i);
+    out.Write(")\n\n");
   }
 
   if (ApiType == APIType::OpenGL || ApiType == APIType::Vulkan)
@@ -788,11 +772,18 @@ ShaderCode GenPixelShader(APIType ApiType, const ShaderHostConfig& host_config,
   // Disable texturing when there are no texgens (for now)
   if (numTexgen != 0)
   {
-    out.Write("    uint tex_coord = {};\n",
+    for (u32 i = 0; i < numTexgen; i++)
+    {
+      out.Write("    int2 fixpoint_uv{} = int2(", i);
+      out.Write("(tex{}.z == 0.0 ? tex{}.xy : tex{}.xy / tex{}.z)", i, i, i, i);
+      out.Write(" * " I_TEXDIMS "[{}].zw);\n", i);
+      // TODO: S24 overflows here?
+    }
+
+    out.Write("\n"
+              "    uint tex_coord = {};\n",
               BitfieldExtract<&TwoTevStageOrders::texcoord0>("ss.order"));
-    out.Write("    float3 uv = getTexCoord(tex_coord);\n"
-              "    int2 fixedPoint_uv = int2((uv.z == 0.0 ? uv.xy : (uv.xy / uv.z)) * " I_TEXDIMS
-              "[tex_coord].zw);\n"
+    out.Write("    int2 fixedPoint_uv = getTexCoord(tex_coord);\n"
               "\n"
               "    bool texture_enabled = (ss.order & {}u) != 0u;\n",
               1 << TwoTevStageOrders().enable0.StartBit());