SkPatch abstraction

gm/patch.cpp

Index: gm/patch.cpp
diff --git a/gm/patch.cpp b/gm/patch.cpp
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+
+/*
+ * Copyright 2013 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 "SkColorPriv.h"
+#include "SkDevice.h"
+#include "SkGeometry.h"
+
+#include "SkPatch.h"
+
+#include <stdio.h>
+
+namespace {
+extern const GrVertexAttrib kAttribs[] = {
+    {kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
+    {kVec4ub_GrVertexAttribType, sizeof(SkPoint), kColor_GrVertexAttribBinding}
+};
+}
+
+namespace skiagm {
+/**
+ * This GM directly exercises effects that draw Bezier curves in the GPU backend.
+ */
+class SkPatchGM : public GM {
+public:
+    SkPatchGM() {
+        this->setBGColor(0xFFFFFFFF);
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("skpatch");
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return SkISize::Make(800, 800);
+    }
+
+    virtual uint32_t onGetFlags() const SK_OVERRIDE {
+        // This is a GPU-specific GM.
+        return kGPUOnly_Flag;
+    }
+
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+
+        SkPaint paint;
+        SkColor colors[4] = {
+            SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorCYAN
+        };
+        SkPoint points[] = {
+            {100,100}, {130,50}, {500,70}, {650,60},
+            {110,590}, {140,550}, {515,595}, {600,700},
+            {70,150}, {125,400},
+            {350,125}, {490,555}
+        };
+
+        SkCoonsPatch coons(points, &colors, 10);
+
+        GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
+        if (NULL != rt && NULL != rt->getContext()) {
+            GrContext* context = rt->getContext();
+            GrTestTarget tt;
+            context->getTestTarget(&tt);
+            SkASSERT(NULL != tt.target());
+            GrDrawState* drawState = tt.target()->drawState();
+            drawState->setVertexAttribs<kAttribs>(2);
+
+            drawState->setRenderTarget(rt);
+
+            //set up mesh, defines grcolors, no texture coordinates and intercalated data
+            SkPatchMesh meshGpu;
+            coons.genMesh(&meshGpu, SkPatchMesh::kGrColor_ColorFormat, false, true);  
+
+            tt.target()->setVertexSourceToArray(meshGpu.getData(), meshGpu.getVertexCount());
+            tt.target()->setIndexSourceToArray(meshGpu.getIndices(), meshGpu.getIndexCount());
+            tt.target()->drawIndexed(kTriangles_GrPrimitiveType, 0, 0, meshGpu.getVertexCount(), 
+                meshGpu.getIndexCount());
+        } else {
+            SkPatchMesh mesh;
+
+            coons.genMesh(&mesh, SkPatchMesh::kSkColor_ColorFormat, false, false);
+
+            canvas->drawVertices(SkCanvas::kTriangles_VertexMode,mesh.getVertexCount(),
+                mesh.getPoints(), NULL, mesh.getColors(), NULL, mesh.getIndices(), 
+                mesh.getIndexCount(), paint);
+        }
+        //draw control points
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, coons.getBottomPoints(), paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, coons.getTopPoints(), paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, coons.getLeftPoints(), paint);
+        canvas->drawPoints(SkCanvas::kLines_PointMode, 4, coons.getRightPoints(), paint);
+
+        paint.setStrokeWidth(5);
+        paint.setColor(SK_ColorRED);
+
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, coons.getBottomPoints(), paint);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, coons.getTopPoints(), paint);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, coons.getLeftPoints(), paint);
+        canvas->drawPoints(SkCanvas::kPoints_PointMode, 4, coons.getRightPoints(), paint);
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+DEF_GM( return SkNEW(SkPatchGM); )
+
+}
+
+#endif