Added tests for radial gradients with shader matrices

gm/gradient_matrix.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkColor.h"
 #include "SkGradientShader.h"
@@ skipping 19 matching lines @@
     {{0, 0}, {0, 1}},
     {{1, 0}, {0, 0}},
     {{0, 1}, {0, 0}},
 
     {{0, 0}, {1, 1}},
     {{1, 1}, {0, 0}},
     {{1, 0}, {0, 1}},
     {{0, 1}, {1, 0}}
 };
 
+static const SkPoint radialPts[][2] = {
+    {{0,   0.5}, {1,   0.5}},
+    {{0.5, 0  }, {0.5, 1  }},
+    {{1,   0.5}, {0,   0.5}},
+    {{0.5, 1  }, {0.5, 0  }},
+
+    {{0, 0}, {1, 1}},
+    {{1, 1}, {0, 0}},
+    {{1, 0}, {0, 1}},
+    {{0, 1}, {1, 0}}
+};
+
+
 static const SkScalar TESTGRID_X = 200;    // pixels allocated to each image in x dimension
 static const SkScalar TESTGRID_Y = 200;    // pixels allocated to each image in y dimension
 
 static const int IMAGES_X = 4;             // number of images per row
 
 static SkShader* make_linear_gradient(const SkPoint pts[2]) {
     return SkGradientShader::CreateLinear(pts, gColors, NULL, SK_ARRAY_COUNT(gColors),
                                           SkShader::kClamp_TileMode, NULL);
 }
 
+static SkShader* make_radial_gradient(const SkPoint pts[2]) {
+    SkPoint center;
+    center.set(SkScalarAve(pts[0].fX, pts[1].fX),
+               SkScalarAve(pts[0].fY, pts[1].fY));
+    float radius = (center - pts[0]).length();
+    return SkGradientShader::CreateRadial(center, radius, gColors, NULL, SK_ARRAY_COUNT(gColors),
+                                          SkShader::kClamp_TileMode, NULL);
+}
+
 static void draw_gradients(SkCanvas* canvas, SkShader* (*makeShader)(const SkPoint[2]),
-                    const SkPoint ptsArray[][2], int numImages) {
+                           const SkPoint ptsArray[][2], int numImages) {
     // Use some nice prime numbers for the rectangle and matrix with
     // different scaling along the x and y axes (which is the bug this
     // test addresses, where incorrect order of operations mixed up the axes)
     SkRect rectGrad = { 43, 61, 181, 167 };
     SkMatrix shaderMat;
     shaderMat.setScale(rectGrad.width(), rectGrad.height());
     shaderMat.postTranslate(rectGrad.left(), rectGrad.top());
 
     canvas->save();
     for (int i = 0; i < numImages; i++) {
@@ skipping 32 matching lines @@
         return SkString("gradient_matrix");
     }
 
     virtual SkISize onISize() SK_OVERRIDE {
         return SkISize::Make(800, 800);
     }
 
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         draw_gradients(canvas, &make_linear_gradient,
                       linearPts, SK_ARRAY_COUNT(linearPts));
+
+        canvas->translate(0, TESTGRID_Y);
+
+        draw_gradients(canvas, &make_radial_gradient,
+                      radialPts, SK_ARRAY_COUNT(radialPts));
     }
 
 private:
     typedef GM INHERITED;
 };
 
 DEF_GM( return new GradientMatrixGM; )
 }