Exact Ganesh Gradients for Special Cases

src/effects/gradients/SkSweepGradient.cpp

Index: src/effects/gradients/SkSweepGradient.cpp
diff --git a/src/effects/gradients/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index 6e32aa3b7b5eb0da137f1a283180e197e65de2a0..505cfd2c95d4d722e038afe9a51232f982e8aa29 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -218,10 +218,10 @@ void GrSweepGradient::GLSLSweepProcessor::emitCode(EmitArgs& args) {
     // On Intel GPU there is an issue where it reads the second arguement to atan "- %s.x" as an int
     // thus must us -1.0 * %s.x to work correctly
     if (args.fGLSLCaps->mustForceNegatedAtanParamToFloat()){
-        t.printf("atan(- %s.y, -1.0 * %s.x) * 0.1591549430918 + 0.5",
+        t.printf("(atan(- %s.y, -1.0 * %s.x) * 0.1591549430918 + 0.5)",
                  coords2D.c_str(), coords2D.c_str());
     } else {
-        t.printf("atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5",
+        t.printf("(atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5)",
                  coords2D.c_str(), coords2D.c_str());
     }
     this->emitColor(args.fFragBuilder,