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

src/gpu/effects/GrRRectEffect.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 "GrRRectEffect.h"
 
 #include "gl/GrGLEffect.h"
@@ skipping 181 matching lines @@
     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
     // The code below is a simplified version of the above that performs maxs on the vector
     // components before computing distances and alpha values so that only one distance computation
     // need be computed to determine the min alpha.
     //
     // For the cases where one half of the rrect is rectangular we drop one of the x or y
     // computations, compute a separate rect edge alpha for the rect side, and mul the two computed
     // alphas together.
     switch (crre.getCircularCornerFlags()) {
         case CircularRRectEffect::kAll_CornerFlags:
-            builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s;\n", rectName, fragmentPos);
-            builder->fsCodeAppendf("\t\tvec2 dxy1 = %s - %s.zw;\n", fragmentPos, rectName);
+            builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
+            builder->fsCodeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
             builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
             builder->fsCodeAppendf("\t\tfloat alpha = clamp(%s - length(dxy), 0.0, 1.0);\n",
                                    radiusPlusHalfName);
             break;
         case CircularRRectEffect::kTopLeft_CornerFlag:
             builder->fsCodeAppendf("\t\tvec2 dxy = max(%s.xy - %s.xy, 0.0);\n",
                                    rectName, fragmentPos);
             builder->fsCodeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
                                     rectName, fragmentPos);
             builder->fsCodeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
@@ skipping 316 matching lines @@
     // to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
     // to that corner. This means that points near the interior near the rrect top edge will have
     // a vector that points straight up for both the TL left and TR corners. Computing an
     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
     // fragments near the other three edges will get the correct AA. Fragments in the interior of
     // the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
     // The code below is a simplified version of the above that performs maxs on the vector
     // components before computing distances and alpha values so that only one distance computation
     // need be computed to determine the min alpha.
-    builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s;\n", rectName, fragmentPos);
-    builder->fsCodeAppendf("\t\tvec2 dxy1 = %s - %s.zw;\n", fragmentPos, rectName);
+    builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
+    builder->fsCodeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
     switch (erre.getRRect().getType()) {
         case SkRRect::kSimple_Type: {
             const char *invRadiiXYSqdName;
             fInvRadiiSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                                       kVec2f_GrSLType,
                                                       "invRadiiXY",
                                                       &invRadiiXYSqdName);
             builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
             // Z is the x/y offsets divided by squared radii.
             builder->fsCodeAppendf("\t\tvec2 Z = dxy * %s;\n", invRadiiXYSqdName);
@@ skipping 169 matching lines @@
                 if (rrect.isNinePatch()) {
                     return EllipticalRRectEffect::Create(edgeType, rrect);
                 }
                 return NULL;
             }
         }
     }
 
     return NULL;
 }