Implement texelFetch and texelFetchOffset.

src/compiler/translator/Initialize.cpp

@@ -503,6 +503,14 @@ void InsertBuiltInFunctions(ShShaderType type, ShShaderSpec spec, const ShBuiltI
     symbolTable.insertBuiltIn(ESSL3_BUILTINS, gvec4, "textureProjLodOffset", gsampler3D, float4, float1, int3);
     symbolTable.insertBuiltIn(ESSL3_BUILTINS, float1, "textureProjLodOffset", sampler2DShadow, float4, float1, int2);
 
+    symbolTable.insertBuiltIn(ESSL3_BUILTINS, gvec4, "texelFetch", gsampler2D, int2, int1);
+    symbolTable.insertBuiltIn(ESSL3_BUILTINS, gvec4, "texelFetch", gsampler3D, int3, int1);
+    symbolTable.insertBuiltIn(ESSL3_BUILTINS, gvec4, "texelFetch", gsampler2DArray, int3, int1);
+
+    symbolTable.insertBuiltIn(ESSL3_BUILTINS, gvec4, "texelFetchOffset", gsampler2D, int2, int1, int2);
+    symbolTable.insertBuiltIn(ESSL3_BUILTINS, gvec4, "texelFetchOffset", gsampler3D, int3, int1, int3);
+    symbolTable.insertBuiltIn(ESSL3_BUILTINS, gvec4, "texelFetchOffset", gsampler2DArray, int3, int1, int2);
+
     //
     // Depth range in window coordinates
     //

src/compiler/translator/OutputHLSL.cpp

@@ -60,6 +60,7 @@ TString OutputHLSL::TextureFunction::name() const
       case LOD:      name += "Lod";   break;
       case LOD0:     name += "Lod0";  break;
       case SIZE:     name += "Size";  break;
+      case FETCH:    name += "Fetch"; break;
       default: UNREACHABLE();
     }
 
@@ -1000,14 +1001,26 @@ void OutputHLSL::header()
         }
         else UNREACHABLE();
 
+        if (textureFunction->method == TextureFunction::FETCH)   // Integer coordinates
+        {
+            switch(textureFunction->coords)
+            {
+              case 2: out << ", int2 t"; break;
+              case 3: out << ", int3 t"; break;
+              default: UNREACHABLE();
+            }
+        }
+        else   // Floating-point coordinates (except textureSize)
+        {
             switch(textureFunction->coords)
             {
-          case 1: out << ", int lod";  break;
+              case 1: out << ", int lod";  break;   // textureSize()
               case 2: out << ", float2 t"; break;
               case 3: out << ", float3 t"; break;
               case 4: out << ", float4 t"; break;
               default: UNREACHABLE();
             }
+        }
 
         switch(textureFunction->method)
         {
@@ -1016,6 +1029,7 @@ void OutputHLSL::header()
           case TextureFunction::LOD:      out << ", float lod";  break;
           case TextureFunction::LOD0:                            break;
           case TextureFunction::SIZE:                            break;
+          case TextureFunction::FETCH:    out << ", int mip";    break;
           default: UNREACHABLE();
         }
 
@@ -1103,7 +1117,8 @@ void OutputHLSL::header()
         }
         else
         {
-            if (IsIntegerSampler(textureFunction->sampler))
+            if (IsIntegerSampler(textureFunction->sampler) &&
+                textureFunction->method != TextureFunction::FETCH)
             {
                 if (IsSampler2D(textureFunction->sampler))
                 {
@@ -1228,7 +1243,8 @@ void OutputHLSL::header()
             }
             else if (mOutputType == SH_HLSL11_OUTPUT)
             {
-                if (IsIntegerSampler(textureFunction->sampler))
+                if (IsIntegerSampler(textureFunction->sampler) ||
+                    textureFunction->method == TextureFunction::FETCH)
                 {
                     out << "x.Load(";
                 }
@@ -1256,7 +1272,8 @@ void OutputHLSL::header()
             TString addressz = "";
             TString close = "";
 
-            if (IsIntegerSampler(textureFunction->sampler))
+            if (IsIntegerSampler(textureFunction->sampler) ||
+                textureFunction->method == TextureFunction::FETCH)
             {
                 switch(hlslCoords)
                 {
@@ -1265,6 +1282,9 @@ void OutputHLSL::header()
                   default: UNREACHABLE();
                 }
             
+                // Convert from normalized floating-point to integer
+                if (textureFunction->method != TextureFunction::FETCH)
+                {
                     addressx = "int(floor(width * frac((";
                     addressy = "int(floor(height * frac((";
 
@@ -1279,6 +1299,7 @@ void OutputHLSL::header()
 
                     close = "))))";
                 }
+            }
             else
             {
                 switch(hlslCoords)
@@ -1338,7 +1359,8 @@ void OutputHLSL::header()
                     out << ", " + addressz + ("t.z" + proj) + close;
                 }
 
-                if (IsIntegerSampler(textureFunction->sampler))
+                if (IsIntegerSampler(textureFunction->sampler) ||
+                    textureFunction->method == TextureFunction::FETCH)
                 {
                     out << ", mip)";
                 }
@@ -2369,6 +2391,15 @@ bool OutputHLSL::visitAggregate(Visit visit, TIntermAggregate *node)
                     textureFunction.proj = true;
                     textureFunction.offset = true;
                 }
+                else if (name == "texelFetch")
+                {
+                    textureFunction.method = TextureFunction::FETCH;
+                }
+                else if (name == "texelFetchOffset")
+                {
+                    textureFunction.method = TextureFunction::FETCH;
+                    textureFunction.offset = true;
+                }
                 else UNREACHABLE();
 
                 if (textureFunction.method == TextureFunction::IMPLICIT)   // Could require lod 0 or have a bias argument

src/compiler/translator/OutputHLSL.h

@@ -104,7 +104,8 @@ class OutputHLSL : public TIntermTraverser
             BIAS,
             LOD,
             LOD0,
-            SIZE   // textureSize()
+            SIZE,   // textureSize()
+            FETCH
         };
 
         TBasicType sampler;