Express (GLSL expression, possibly known value) pairs as a class

src/effects/gradients/SkGradientShader.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGradientShaderPriv.h"
 #include "SkLinearGradient.h"
 #include "SkRadialGradient.h"
@@ skipping 932 matching lines @@
                                gradientTValue);
         // Note that we could skip this step if both colors are known to be opaque. Two
         // considerations:
         // The gradient SkShader reporting opaque is more restrictive than necessary in the two pt
         // case. Make sure the key reflects this optimization (and note that it can use the same
         // shader as thekBeforeIterp case). This same optimization applies to the 3 color case below.
         if (GrGradientEffect::kAfterInterp_PremulType == PremulTypeFromKey(key)) {
             builder->fsCodeAppend("\tcolorTemp.rgb *= colorTemp.a;\n");
         }
 
-        SkString output;
-        builder->fsCodeAppendf("\t%s = ", outputColor);
-        GrGLSLModulatef<4>(&output, inputColor, "colorTemp");
-        builder->fsCodeAppend(output.c_str());
-        builder->fsCodeAppend(";\n");
+        builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
+                               (GrGLSLExpr<4>(inputColor) * GrGLSLExpr<4>("colorTemp")).c_str());
     } else if (GrGradientEffect::kThree_ColorType == ColorTypeFromKey(key)){
         builder->fsCodeAppendf("\tfloat oneMinus2t = 1.0 - (2.0 * (%s));\n",
                                gradientTValue);
         builder->fsCodeAppendf("\tvec4 colorTemp = clamp(oneMinus2t, 0.0, 1.0) * %s;\n",
                                builder->getUniformVariable(fColorStartUni).c_str());
         if (kTegra3_GrGLRenderer == builder->ctxInfo().renderer()) {
             // The Tegra3 compiler will sometimes never return if we have
             // min(abs(oneMinus2t), 1.0), or do the abs first in a separate expression.
             builder->fsCodeAppend("\tfloat minAbs = abs(oneMinus2t);\n");
             builder->fsCodeAppend("\tminAbs = minAbs > 1.0 ? 1.0 : minAbs;\n");
             builder->fsCodeAppendf("\tcolorTemp += (1.0 - minAbs) * %s;\n",
                                    builder->getUniformVariable(fColorMidUni).c_str());
         } else {
             builder->fsCodeAppendf("\tcolorTemp += (1.0 - min(abs(oneMinus2t), 1.0)) * %s;\n",
                                    builder->getUniformVariable(fColorMidUni).c_str());
         }
         builder->fsCodeAppendf("\tcolorTemp += clamp(-oneMinus2t, 0.0, 1.0) * %s;\n",
                                builder->getUniformVariable(fColorEndUni).c_str());
         if (GrGradientEffect::kAfterInterp_PremulType == PremulTypeFromKey(key)) {
             builder->fsCodeAppend("\tcolorTemp.rgb *= colorTemp.a;\n");
         }
 
-        SkString output;
-        builder->fsCodeAppendf("\t%s = ", outputColor);
-        GrGLSLModulatef<4>(&output, inputColor, "colorTemp");
-        builder->fsCodeAppend(output.c_str());
-        builder->fsCodeAppend(";\n");
+        builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
+                               (GrGLSLExpr<4>(inputColor) * GrGLSLExpr<4>("colorTemp")).c_str());
     } else {
         builder->fsCodeAppendf("\tvec2 coord = vec2(%s, %s);\n",
                                gradientTValue,
                                builder->getUniformVariable(fFSYUni).c_str());
         builder->fsCodeAppendf("\t%s = ", outputColor);
         builder->fsAppendTextureLookupAndModulate(inputColor,
                                                   samplers[0],
                                                   "coord");
         builder->fsCodeAppend(";\n");
     }
@@ skipping 144 matching lines @@
             (*stops)[i] = stop;
             stop = i < outColors - 1 ? stop + random->nextUScalar1() * (1.f - stop) : 1.f;
         }
     }
     *tm = static_cast<SkShader::TileMode>(random->nextULessThan(SkShader::kTileModeCount));
 
     return outColors;
 }
 
 #endif