Add arb_texture_rectangle support properly in GLES3 shaders

src/gpu/glsl/GrGLSL.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSL_DEFINED
 #define GrGLSL_DEFINED
 
 #include "GrTypesPriv.h"
 #include "SkString.h"
-
-class GrGLSLCaps;
-
-// Limited set of GLSL versions we build shaders for. Caller should round
-// down the GLSL version to one of these enums.
-enum GrGLSLGeneration {
-    /**
-     * Desktop GLSL 1.10 and ES2 shading language (based on desktop GLSL 1.20)
-     */
-    k110_GrGLSLGeneration,
-    /**
-     * Desktop GLSL 1.30
-     */
-    k130_GrGLSLGeneration,
-    /**
-     * Desktop GLSL 1.40
-     */
-    k140_GrGLSLGeneration,
-    /**
-     * Desktop GLSL 1.50
-     */
-    k150_GrGLSLGeneration,
-    /**
-     * Desktop GLSL 3.30, and ES GLSL 3.00
-     */
-    k330_GrGLSLGeneration,
-    /**
-     * ES GLSL 3.10 only TODO Make GLSLCap objects to make this more granular
-     */
-    k310es_GrGLSLGeneration,
-};
+#include "GrGLSLCaps.h"
 
 bool GrGLSLSupportsNamedFragmentShaderOutputs(GrGLSLGeneration);
 
 /**
  * Gets the name of the function that should be used to sample a 2D texture. Coord type is used
  * to indicate whether the texture is sampled using projective textured (kVec3f) or not (kVec2f).
  */
 inline const char* GrGLSLTexture2DFunctionName(GrSLType coordType, GrSLType samplerType,
-                                               GrGLSLGeneration glslGen) {
+                                               const GrGLSLCaps& glslCaps) {
     SkASSERT(GrSLTypeIsSamplerType(samplerType));
     SkASSERT(kVec2f_GrSLType == coordType || kVec3f_GrSLType == coordType);
     // GL_TEXTURE_RECTANGLE_ARB is written against OpenGL 2.0/GLSL 1.10. At that time there were
     // separate texture*() functions. In OpenGL 3.0/GLSL 1.30 the different texture*() functions
     // were deprecated in favor or the unified texture() function. RECTANGLE textures became
     // standard in OpenGL 3.2/GLSL 1.50 and use texture(). It isn't completely clear what function
     // should be used for RECTANGLE textures in GLSL versions >= 1.30 && < 1.50. We're going with
     // using texture().
-    if (glslGen >= k130_GrGLSLGeneration) {
-        return (kVec2f_GrSLType == coordType) ? "texture" : "textureProj";
+    if (samplerType == kSampler2DRect_GrSLType &&
+        !glslCaps.rectangleTextureUseUnifiedTextureFunctionName()) {
+        if (kVec2f_GrSLType == coordType) {
+            return "texture2DRect";
+        }
+        return "texture2DRectProj";
+    }
+    if (glslCaps.generation() >= k130_GrGLSLGeneration) {
+        if (kVec2f_GrSLType == coordType) {
+            return "texture";
+        }
+        return "textureProj";
     }
     if (kVec2f_GrSLType == coordType) {
-        return (samplerType == kSampler2DRect_GrSLType) ? "texture2DRect" : "texture2D";
-    } else {
-        return (samplerType == kSampler2DRect_GrSLType) ? "texture2DRectProj" : "texture2DProj";
+        return "texture2D";
     }
+    return "texture2DProj";
 }
 
 /**
  * Adds a line of GLSL code to declare the default precision for float types.
  */
 void GrGLSLAppendDefaultFloatPrecisionDeclaration(GrSLPrecision,
                                                   const GrGLSLCaps& glslCaps,
                                                   SkString* out);
 
 /**
@@ skipping 268 matching lines @@
 
 /**
  * Does an inplace mul, *=, of vec4VarName by mulFactor.
  * A semicolon is added after the assignment.
  */
 void GrGLSLMulVarBy4f(SkString* outAppend, const char* vec4VarName, const GrGLSLExpr4& mulFactor);
 
 #include "GrGLSL_impl.h"
 
 #endif