Fix int to float bug in shader on gpu Dotted Line cl

src/gpu/effects/GrDashingEffect.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDashingEffect.h"
 
 #include "../GrAARectRenderer.h"
@@ skipping 508 matching lines @@
     builder->vsCodeAppendf("\t%s = %s;\n", vsCoordName, attr0Name->c_str());
 
     // transforms all points so that we can compare them to our test circle
     builder->fsCodeAppendf("\t\tfloat xShifted = %s.x - floor(%s.x / %s.z) * %s.z;\n",
                            fsCoordName, fsCoordName, paramName, paramName);
     builder->fsCodeAppendf("\t\tvec2 fragPosShifted = vec2(xShifted, %s.y);\n", fsCoordName);
     builder->fsCodeAppendf("\t\tvec2 center = vec2(%s.y, 0.0);\n", paramName);
     builder->fsCodeAppend("\t\tfloat dist = length(center - fragPosShifted);\n");
     if (GrEffectEdgeTypeIsAA(dce.getEdgeType())) {
         builder->fsCodeAppendf("\t\tfloat diff = dist - %s.x;\n", paramName);
-        builder->fsCodeAppend("\t\tdiff = 1 - diff;\n");
+        builder->fsCodeAppend("\t\tdiff = 1.0 - diff;\n");
         builder->fsCodeAppend("\t\tfloat alpha = clamp(diff, 0.0, 1.0);\n");
     } else {
         builder->fsCodeAppendf("\t\tfloat alpha = 1.0;\n");
         builder->fsCodeAppendf("\t\talpha *=  dist < %s.x + 0.5 ? 1.0 : 0.0;\n", paramName);
     }
     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
 }
 
 void GLDashingCircleEffect::setData(const GrGLUniformManager& uman, const GrDrawEffect& drawEffect) {
@@ skipping 305 matching lines @@
     switch (cap) {
         case GrDashingEffect::kRound_DashCap:
             return DashingCircleEffect::Create(edgeType, info, SkScalarHalf(strokeWidth));
         case GrDashingEffect::kNonRound_DashCap:
             return DashingLineEffect::Create(edgeType, info, strokeWidth);
         default:
             SkFAIL("Unexpected dashed cap.");
     }
     return NULL;
 }