Add appendPrecisionModifier method to GrGLSLShaderBuilder

src/gpu/glsl/GrGLSLShaderVar.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 GrGLSLShaderVar_DEFINED
 #define GrGLSLShaderVar_DEFINED
 
@@ skipping 156 matching lines @@
         SkASSERT(kDefault_GrSLPrecision == fPrecision || GrSLTypeAcceptsPrecision(fType));
         if (!fLayoutQualifier.isEmpty()) {
             out->appendf("layout(%s) ", fLayoutQualifier.c_str());
         }
         out->append(fExtraModifiers);
         if (this->getTypeModifier() != kNone_TypeModifier) {
             out->append(TypeModifierString(glslCaps, this->getTypeModifier()));
             out->append(" ");
         }
         GrSLType effectiveType = this->getType();
-        if (GrSLTypeAcceptsPrecision(effectiveType)) {
-            out->append(PrecisionString(glslCaps, fPrecision));
+        if (glslCaps->usesPrecisionModifiers() && GrSLTypeAcceptsPrecision(effectiveType)) {
+            // Desktop GLSL has added precision qualifiers but they don't do anything.
+            out->appendf("%s ", GrGLSLPrecisionString(fPrecision));
         }
         if (this->isArray()) {
             if (this->isUnsizedArray()) {
                 out->appendf("%s %s[]",
                              GrGLSLTypeString(effectiveType),
                              this->getName().c_str());
             } else {
                 SkASSERT(this->getArrayCount() > 0);
                 out->appendf("%s %s[%d]",
                              GrGLSLTypeString(effectiveType),
@@ skipping 14 matching lines @@
                      fUseUniformFloatArrays ? "" : ".x");
     }
 
     void appendArrayAccess(const char* indexName, SkString* out) const {
         out->appendf("%s[%s]%s",
                      this->getName().c_str(),
                      indexName,
                      fUseUniformFloatArrays ? "" : ".x");
     }
 
-    static const char* PrecisionString(const GrGLSLCaps* glslCaps, GrSLPrecision p) {
-        // Desktop GLSL has added precision qualifiers but they don't do anything.
-        if (glslCaps->usesPrecisionModifiers()) {
-            switch (p) {
-                case kLow_GrSLPrecision:
-                    return "lowp ";
-                case kMedium_GrSLPrecision:
-                    return "mediump ";
-                case kHigh_GrSLPrecision:
-                    return "highp ";
-                default:
-                    SkFAIL("Unexpected precision type.");
-            }
-        }
-        return "";
-    }
-
 private:
     static const char* TypeModifierString(const GrGLSLCaps* glslCaps, TypeModifier t) {
         GrGLSLGeneration gen = glslCaps->generation();
         switch (t) {
             case kNone_TypeModifier:
                 return "";
             case kIn_TypeModifier:
                 return "in";
             case kInOut_TypeModifier:
                 return "inout";
@@ skipping 17 matching lines @@
     /// support uniform float []
     bool        fUseUniformFloatArrays;
 
     SkString    fLayoutQualifier;
     SkString    fExtraModifiers;
 
     typedef GrShaderVar INHERITED;
 };
 
 #endif