SkPatch abstraction

gm/patch.cpp

Index: gm/patch.cpp
diff --git a/gm/patch.cpp b/gm/patch.cpp
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+++ b/gm/patch.cpp
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+
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+// This test only works with the GPU backend.
+
+#include "gm.h"
+
+#if SK_SUPPORT_GPU
+
+#include "GrContext.h"
+#include "GrTest.h"
+
+#include "SkPatch.h"
+
+namespace skiagm {
+/**
+ * This GM draws a SkPatch.
+ */
+class SkPatchGM : public GM {
+public:
+    SkPatchGM() {
+        this->setBGColor(0xFFFFFFFF);
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("patch_primitive");
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return SkISize::Make(800, 800);
+    }
+
+    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+        return kSkipTiled_Flag;
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+
+        SkPaint paint;
+        
+        SkColor colors[4] = {
+            SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
+        };
+        SkPoint points[12] = {
+            {100,100},{130,50},{500,70}, {650,60},
+            {350,125},{490,555},{600,700},
+            {515,595},{140,550},{110,590},
+            {125,400},{70,150}
+        };
+        
+        SkPatch coons(points, colors);
+        SkPatch::VertexData data;
+        coons.getVertexData(&data, 10);
+        
+        canvas->drawVertices(SkCanvas::kTriangles_VertexMode,data.fVertexCount,
+            data.fPoints, data.fTexCoords, data.fColors, NULL, data.fIndices,
+            data.fIndexCount, paint);
+
+        //draw control points
+        SkPoint bottom[4];
+        coons.getBottomPoints(bottom);
+        SkPoint top[4];
+        coons.getTopPoints(top);
+        SkPoint left[4];
+        coons.getLeftPoints(left);
+        SkPoint right[4];
+        coons.getRightPoints(right);
+
+        SkPoint corners[4] = { bottom[0], bottom[3], top[0], top[3] };
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, bottom, paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, bottom+1, paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, top, paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, left, paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, right, paint);
+
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, top+1, paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, left+1, paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 2, right+1, paint);
+
+        paint.setStrokeWidth(10);
+
+        paint.setColor(SK_ColorRED);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, corners, paint);
+
+        paint.setColor(SK_ColorBLUE);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, bottom+1, paint);
+
+        paint.setColor(SK_ColorCYAN);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, top+1, paint);
+
+        paint.setColor(SK_ColorYELLOW);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, left+1, paint);
+
+        paint.setColor(SK_ColorGREEN);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 2, right+1, paint);
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+DEF_GM( return SkNEW(SkPatchGM); )
+
+}
+
+#endif