Fix color bug in SkRRectsGaussianEdgeShader

Due to the code at the end of emitCode this shader was darker than the SkGaussianEdgeShader on Android.

This CL also removes the unused "pad" parameter.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2344963002
NOTREECHECKS=true
TBR=bsalomon@google.com

Review-Url: https://codereview.chromium.org/2344963002

1 files changed, 36 insertions, 47 deletions

diff --git a/src/effects/SkRRectsGaussianEdgeShader.cpp b/src/effects/SkRRectsGaussianEdgeShader.cpp
index 02e46fb874..2c41c26c10 100644
--- a/src/effects/SkRRectsGaussianEdgeShader.cpp
+++ b/src/effects/SkRRectsGaussianEdgeShader.cpp
@@ -16,12 +16,10 @@
   */
 class SkRRectsGaussianEdgeShaderImpl : public SkShader {
 public:
-    SkRRectsGaussianEdgeShaderImpl(const SkRRect& first, const SkRRect& second,
-                                   SkScalar radius, SkScalar pad)
+    SkRRectsGaussianEdgeShaderImpl(const SkRRect& first, const SkRRect& second, SkScalar radius)
         : fFirst(first)
         , fSecond(second)
-        , fRadius(radius)
-        , fPad(pad) {
+        , fRadius(radius) {
     }
 
     bool isOpaque() const override { return false; }
@@ -58,7 +56,6 @@ private:
     SkRRect  fFirst;
     SkRRect  fSecond;
     SkScalar fRadius;
-    SkScalar fPad;
 
     friend class SkRRectsGaussianEdgeShader; // for serialization registration system
 
@@ -87,12 +84,10 @@ public:
         kSimpleCircular_Mode,
     };
 
-    RRectsGaussianEdgeFP(const SkRRect& first, const SkRRect& second,
-                         SkScalar radius, SkScalar pad)
+    RRectsGaussianEdgeFP(const SkRRect& first, const SkRRect& second, SkScalar radius)
         : fFirst(first)
         , fSecond(second)
-        , fRadius(radius)
-        , fPad(pad) {
+        , fRadius(radius) {
         this->initClassID<RRectsGaussianEdgeFP>();
         this->setWillReadFragmentPosition();
 
@@ -112,7 +107,7 @@ public:
                           const char* posName,
                           const char* sizesName,
                           const char* radiiName,
-                          const char* padRadName,
+                          const char* radName,
                           const char* outputName,
                           const char  indices[2]) { // how to access the params for the 2 rrects
 
@@ -122,15 +117,15 @@ public:
 
             switch (mode) {
             case kCircle_Mode:
-                fragBuilder->codeAppendf("%s = clamp((%s.%c - length(delta))/%s.y, 0.0, 1.0);",
-                                         outputName, sizesName, indices[0], padRadName);
+                fragBuilder->codeAppendf("%s = clamp((%s.%c - length(delta))/%s, 0.0, 1.0);",
+                                         outputName, sizesName, indices[0], radName);
                 break;
             case kRect_Mode:
                 fragBuilder->codeAppendf(
-                    "vec2 rectDist = vec2(1.0 - clamp((%s.%c - abs(delta.x))/%s.y, 0.0, 1.0),"
-                                         "1.0 - clamp((%s.%c - abs(delta.y))/%s.y, 0.0, 1.0));",
-                    sizesName, indices[0], padRadName,
-                    sizesName, indices[1], padRadName);
+                    "vec2 rectDist = vec2(1.0 - clamp((%s.%c - abs(delta.x))/%s, 0.0, 1.0),"
+                                         "1.0 - clamp((%s.%c - abs(delta.y))/%s, 0.0, 1.0));",
+                    sizesName, indices[0], radName,
+                    sizesName, indices[1], radName);
                 fragBuilder->codeAppendf("%s = 1.0 - length(rectDist);", outputName);
                 break;
             case kSimpleCircular_Mode:
@@ -139,12 +134,12 @@ public:
                 // point is in one of the circular corners. We then compute the
                 // distance from the corner and then use the multiplier to mask
                 // between the two distances.
-                fragBuilder->codeAppendf("float xDist = clamp((%s.%c - abs(delta.x))/%s.y,"
+                fragBuilder->codeAppendf("float xDist = clamp((%s.%c - abs(delta.x))/%s,"
                                                              " 0.0, 1.0);",
-                                         sizesName, indices[0], padRadName);
-                fragBuilder->codeAppendf("float yDist = clamp((%s.%c - abs(delta.y))/%s.y,"
+                                         sizesName, indices[0], radName);
+                fragBuilder->codeAppendf("float yDist = clamp((%s.%c - abs(delta.y))/%s,"
                                                              "0.0, 1.0);",
-                                         sizesName, indices[1], padRadName);
+                                         sizesName, indices[1], radName);
                 fragBuilder->codeAppend("float rectDist = min(xDist, yDist);");
 
                 fragBuilder->codeAppendf("vec2 cornerCenter = %s.%s - %s.%s;",
@@ -158,9 +153,9 @@ public:
 
                 fragBuilder->codeAppendf("delta += %s.%s;", radiiName, indices);
 
-                fragBuilder->codeAppendf("cornerDist = clamp((2.0 * %s.%c - length(delta))/%s.y,"
+                fragBuilder->codeAppendf("cornerDist = clamp((2.0 * %s.%c - length(delta))/%s,"
                                                              "0.0, 1.0);",
-                                         radiiName, indices[0], padRadName);
+                                         radiiName, indices[0], radName);
 
                 fragBuilder->codeAppendf("%s = (multiplier * cornerDist) +"
                                               "((1.0-multiplier) * rectDist);",
@@ -188,34 +183,32 @@ public:
                                                        kVec4f_GrSLType, kDefault_GrSLPrecision,
                                                        "Radii", &radiiUniName);
             }
-            const char* padRadUniName = nullptr;
-            fPadRadUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
-                                                    kVec2f_GrSLType, kDefault_GrSLPrecision,
-                                                    "PadRad", &padRadUniName);
+            const char* radUniName = nullptr;
+            fRadiusUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
+                                                    kFloat_GrSLType, kDefault_GrSLPrecision,
+                                                    "Radius", &radUniName);
 
             fragBuilder->codeAppend("float firstDist;");
             fragBuilder->codeAppend("{");
             this->emitModeCode(fp.firstMode(), fragBuilder,
                                positionsUniName, sizesUniName, radiiUniName,
-                               padRadUniName, "firstDist", "xy");
+                               radUniName, "firstDist", "xy");
             fragBuilder->codeAppend("}");
 
             fragBuilder->codeAppend("float secondDist;");
             fragBuilder->codeAppend("{");
             this->emitModeCode(fp.secondMode(), fragBuilder,
                                positionsUniName, sizesUniName, radiiUniName,
-                               padRadUniName, "secondDist", "zw");
+                               radUniName, "secondDist", "zw");
             fragBuilder->codeAppend("}");
 
-            fragBuilder->codeAppendf("float dist = %s.y * firstDist * secondDist;",
-                                     padRadUniName);
+            fragBuilder->codeAppendf("float dist = %s * firstDist * secondDist;", radUniName);
 
             // Finally use the distance to apply the Gaussian edge
             // TODO: we undo the multiply by the radius here - we should just skip both
-            fragBuilder->codeAppendf("float factor = 1.0 - clamp((dist - %s.x)/%s.y, 0.0, 1.0);",
-                                     padRadUniName, padRadUniName);
+            fragBuilder->codeAppendf("float factor = 1.0 - clamp(dist/%s, 0.0, 1.0);", radUniName);
             fragBuilder->codeAppend("factor = exp(-factor * factor * 4.0) - 0.018;");
-            fragBuilder->codeAppendf("%s = vec4(%s.rgb, factor);",
+            fragBuilder->codeAppendf("%s = factor*%s;",
                                      args.fOutputColor, args.fInputColor);
         }
 
@@ -256,7 +249,7 @@ public:
                              0.5f * second.getSimpleRadii().fY);
             }
 
-            pdman.set2f(fPadRadUni, edgeFP.pad(), edgeFP.radius());
+            pdman.set1f(fRadiusUni, edgeFP.radius());
         }
 
     private:
@@ -273,8 +266,8 @@ public:
         // non-circular corner round rects & ellipses.
         GrGLSLProgramDataManager::UniformHandle fRadiiUni;
 
-        // The pad and radius parameters (padding, radius)
-        GrGLSLProgramDataManager::UniformHandle fPadRadUni;
+        // The radius parameters (radius)
+        GrGLSLProgramDataManager::UniformHandle fRadiusUni;
 
         typedef GrGLSLFragmentProcessor INHERITED;
     };
@@ -294,7 +287,6 @@ public:
     const SkRRect& second() const { return fSecond; }
     Mode secondMode() const { return fSecondMode; }
     SkScalar radius() const { return fRadius; }
-    SkScalar pad() const { return fPad; }
 
 private:
     static Mode ComputeMode(const SkRRect& rr) {
@@ -314,8 +306,9 @@ private:
 
     bool onIsEqual(const GrFragmentProcessor& proc) const override {
         const RRectsGaussianEdgeFP& edgeFP = proc.cast<RRectsGaussianEdgeFP>();
-        return fFirst  == edgeFP.fFirst && fSecond == edgeFP.fSecond && 
-               fRadius == edgeFP.fRadius && fPad == edgeFP.fPad;
+        return fFirst  == edgeFP.fFirst &&
+               fSecond == edgeFP.fSecond && 
+               fRadius == edgeFP.fRadius;
     }
 
     SkRRect  fFirst;
@@ -323,7 +316,6 @@ private:
     SkRRect  fSecond;
     Mode     fSecondMode;
     SkScalar fRadius;
-    SkScalar fPad;
 
     typedef GrFragmentProcessor INHERITED;
 };
@@ -332,7 +324,7 @@ private:
 
 sk_sp<GrFragmentProcessor> SkRRectsGaussianEdgeShaderImpl::asFragmentProcessor(
                                                                     const AsFPArgs& args) const {
-    return sk_make_sp<RRectsGaussianEdgeFP>(fFirst, fSecond, fRadius, fPad);
+    return sk_make_sp<RRectsGaussianEdgeFP>(fFirst, fSecond, fRadius);
 }
 
 #endif
@@ -380,11 +372,10 @@ sk_sp<SkFlattenable> SkRRectsGaussianEdgeShaderImpl::CreateProc(SkReadBuffer& bu
     SkScalar yRad2 = buf.readScalar();
 
     SkScalar radius = buf.readScalar();
-    SkScalar pad = buf.readScalar();
 
     return sk_make_sp<SkRRectsGaussianEdgeShaderImpl>(SkRRect::MakeRectXY(rect1, xRad1, yRad1),
                                                       SkRRect::MakeRectXY(rect2, xRad2, yRad2),
-                                                      radius, pad);
+                                                      radius);
 }
 
 void SkRRectsGaussianEdgeShaderImpl::flatten(SkWriteBuffer& buf) const {
@@ -403,7 +394,6 @@ void SkRRectsGaussianEdgeShaderImpl::flatten(SkWriteBuffer& buf) const {
     buf.writeScalar(radii2.fY);
 
     buf.writeScalar(fRadius);
-    buf.writeScalar(fPad);
 }
 
 size_t SkRRectsGaussianEdgeShaderImpl::onContextSize(const ContextRec& rec) const {
@@ -419,8 +409,7 @@ SkShader::Context* SkRRectsGaussianEdgeShaderImpl::onCreateContext(const Context
 
 sk_sp<SkShader> SkRRectsGaussianEdgeShader::Make(const SkRRect& first,
                                                  const SkRRect& second,
-                                                 SkScalar radius,
-                                                 SkScalar pad) {
+                                                 SkScalar radius) {
     if ((!first.isRect()  && !first.isCircle()  && !first.isSimpleCircular()) || 
         (!second.isRect() && !second.isCircle() && !second.isSimpleCircular())) {
         // we only deal with the shapes where the x & y radii are equal 
@@ -428,7 +417,7 @@ sk_sp<SkShader> SkRRectsGaussianEdgeShader::Make(const SkRRect& first,
         return nullptr;
     }
 
-    return sk_make_sp<SkRRectsGaussianEdgeShaderImpl>(first, second, radius, pad);
+    return sk_make_sp<SkRRectsGaussianEdgeShaderImpl>(first, second, radius);
 }
 
 ///////////////////////////////////////////////////////////////////////////////