Make GrGLShaderBuilder::fragmentPosition() return a vec4, with 1.0 as the zw components when in the…

src/gpu/effects/GrOvalEffect.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 "GrOvalEffect.h"
 
 #include "gl/GrGLEffect.h"
@@ skipping 129 matching lines @@
     // The circle uniform is (center.x, center.y, radius + 0.5) for regular fills and
     // (... ,radius - 0.5) for inverse fills.
     fCircleUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                          kVec3f_GrSLType,
                                          "circle",
                                          &circleName);
     const char* fragmentPos = builder->fragmentPosition();
 
     SkASSERT(kHairlineAA_GrEffectEdgeType != ce.getEdgeType());
     if (GrEffectEdgeTypeIsInverseFill(ce.getEdgeType())) {
-        builder->fsCodeAppendf("\t\tfloat d = length(%s.xy - %s) - %s.z;\n",
+        builder->fsCodeAppendf("\t\tfloat d = length(%s.xy - %s.xy) - %s.z;\n",
                                 circleName, fragmentPos, circleName);
     } else {
-        builder->fsCodeAppendf("\t\tfloat d = %s.z - length(%s - %s.xy);\n",
+        builder->fsCodeAppendf("\t\tfloat d = %s.z - length(%s.xy - %s.xy);\n",
                                circleName, fragmentPos, circleName);
     }
     if (GrEffectEdgeTypeIsAA(ce.getEdgeType())) {
         builder->fsCodeAppend("\t\td = clamp(d, 0.0, 1.0);\n");
     } else {
         builder->fsCodeAppend("\t\td = d > 0.5 ? 1.0 : 0.0;\n");
     }
 
     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("d")).c_str());
@@ skipping 147 matching lines @@
     const EllipseEffect& ee = drawEffect.castEffect<EllipseEffect>();
     const char *ellipseName;
     // The ellipse uniform is (center.x, center.y, 1 / rx^2, 1 / ry^2)
     fEllipseUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                          kVec4f_GrSLType,
                                          "ellipse",
                                          &ellipseName);
     const char* fragmentPos = builder->fragmentPosition();
 
     // d is the offset to the ellipse center
-    builder->fsCodeAppendf("\t\tvec2 d = %s - %s.xy;\n", fragmentPos, ellipseName);
+    builder->fsCodeAppendf("\t\tvec2 d = %s.xy - %s.xy;\n", fragmentPos, ellipseName);
     builder->fsCodeAppendf("\t\tvec2 Z = d * %s.zw;\n", ellipseName);
     // implicit is the evaluation of (x/rx)^2 + (y/ry)^2 - 1.
     builder->fsCodeAppend("\t\tfloat implicit = dot(Z, d) - 1.0;\n");
     // grad_dot is the squared length of the gradient of the implicit.
     builder->fsCodeAppendf("\t\tfloat grad_dot = 4.0 * dot(Z, Z);\n");
     // avoid calling inversesqrt on zero.
     builder->fsCodeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
     builder->fsCodeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n");
 
     switch (ee.getEdgeType()) {
@@ skipping 46 matching lines @@
         w /= 2;
         return CircleEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + w), w);
     } else {
         w /= 2;
         h /= 2;
         return EllipseEffect::Create(edgeType, SkPoint::Make(oval.fLeft + w, oval.fTop + h), w, h);
     }
 
     return NULL;
 }