Registry-based unit test for custom effects

Review URL: http://codereview.appspot.com/6447085/



git-svn-id: http://skia.googlecode.com/svn/trunk@4946 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index 0dee9b5..89ebba2 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -422,13 +422,36 @@
 
     typedef GrGLSweepGradient GLProgramStage;
 
-protected:
+private:
+    GR_DECLARE_CUSTOM_STAGE_TEST;
 
     typedef GrGradientEffect INHERITED;
 };
 
 /////////////////////////////////////////////////////////////////////
 
+GR_DEFINE_CUSTOM_STAGE_TEST(GrSweepGradient);
+
+GrCustomStage* GrSweepGradient::TestCreate(SkRandom* random,
+                                           GrContext* context,
+                                           GrTexture**) {
+    SkPoint center = {random->nextUScalar1(), random->nextUScalar1()};
+
+    SkColor colors[kMaxRandomGradientColors];
+    SkScalar stopsArray[kMaxRandomGradientColors];
+    SkScalar* stops = stopsArray;
+    SkShader::TileMode tmIgnored;
+    int colorCount = RandomGradientParams(random, colors, &stops, &tmIgnored);
+    SkAutoTUnref<SkShader> shader(SkGradientShader::CreateSweep(center.fX, center.fY,
+                                                                colors, stops, colorCount));
+    GrSamplerState sampler;
+    GrCustomStage* stage = shader->asNewCustomStage(context, &sampler);
+    GrAssert(NULL != stage);
+    return stage;
+}
+
+/////////////////////////////////////////////////////////////////////
+
 void GrGLSweepGradient::emitFS(GrGLShaderBuilder* builder,
                               const char* outputColor,
                               const char* inputColor,