Added tests for radial gradients with shader matrices

gm/gradient_matrix.cpp

Index: gm/gradient_matrix.cpp
diff --git a/gm/gradient_matrix.cpp b/gm/gradient_matrix.cpp
index e071788c771b7664a8c9564fb15d8d39da65042a..77bb5b24702d7f12f9c3ad9a4f10e85e55d7fde3 100644
--- a/gm/gradient_matrix.cpp
+++ b/gm/gradient_matrix.cpp
@@ -14,7 +14,7 @@ SkColor gColors[] = {
 };
 
 // these arrays define the gradient stop points
-// as x1, y1, x2, y2 per gradient to draw
+// as {{x1, y1}, {x2, y2}} per gradient to draw
 SkPoint linearPts[][2] = {
     {{0, 0}, {1, 0}},
     {{0, 0}, {0, 1}},
@@ -27,6 +27,19 @@ SkPoint linearPts[][2] = {
     {{0, 1}, {1, 0}}
 };
 
+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}}
+};
+
+
 const SkScalar TESTGRID_X = 200;    // pixels allocated to each image in x dimension
 const SkScalar TESTGRID_Y = 200;    // pixels allocated to each image in y dimension
 
@@ -37,6 +50,15 @@ static SkShader* make_linear_gradient(SkPoint pts[2]) {
                                           SkShader::kClamp_TileMode, NULL);
 }
 
+static SkShader* make_radial_gradient(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);
+}
+
 void draw_gradients(SkCanvas* canvas, SkShader* (*makeShader)(SkPoint[2]),
                     SkPoint ptsArray[][2], int numImages) {
     // common test parameters
@@ -46,7 +68,6 @@ void draw_gradients(SkCanvas* canvas, SkShader* (*makeShader)(SkPoint[2]),
                      0,   0,   1);
     SkRect rectGrad = { 43, 61, 181, 167 }; // some nice prime numbers
 
-    canvas->save();

[vandebo (ex-Chrome), 2013/06/12 16:28:03]

These can stay here.

[ducky, 2013/06/12 18:24:06]

Done.

     for (int i = 0; i < numImages; i++) {
         // advance line if necessary
         if (i % IMAGES_X == 0 && i != 0) {
@@ -67,7 +88,6 @@ void draw_gradients(SkCanvas* canvas, SkShader* (*makeShader)(SkPoint[2]),
         canvas->translate(TESTGRID_X, 0);
         ptsArray++;
     }
-    canvas->restore();
 }
 
 namespace skiagm {
@@ -88,8 +108,19 @@ protected:
     }
 
     virtual void onDraw(SkCanvas* canvas) {
+        canvas->save();
+
         draw_gradients(canvas, &make_linear_gradient,
                       linearPts, SK_ARRAY_COUNT(linearPts));
+
+        canvas->restore();
+        canvas->translate(0, TESTGRID_Y);
+        canvas->save();
+
+        draw_gradients(canvas, &make_radial_gradient,
+                      radialPts, SK_ARRAY_COUNT(radialPts));
+
+        canvas->restore();
     }
 
 private: