Fix for nested rect drawing bug

gm/nested.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 "gm.h"
+#include "SkRandom.h"
+#include "SkRRect.h"
+
+namespace skiagm {
+
+// Test out various combinations of nested rects, ovals and rrects.
+class NestedGM : public GM {
+public:
+    NestedGM(bool doAA) : fDoAA(doAA) {
+        this->setBGColor(0xFFDDDDDD);
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        SkString name("nested");
+        if (fDoAA) {
+            name.append("_aa");
+        } else {
+            name.append("_bw");
+        }
+        return name;
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE { 
+        return make_isize(kImageWidth, kImageHeight); 
+    }
+
+    enum Shapes {
+        kRect_Shape = 0,
+        kRRect_Shape,
+        kOval_Shape,
+        kShapeCount
+    };
+
+    static void AddShape(SkPath* path, const SkRect& rect, Shapes shape, SkPath::Direction dir) {
+        switch (shape) {
+            case kRect_Shape:
+                path->addRect(rect, dir);
+                break;
+            case kRRect_Shape: {
+                SkRRect rr;
+                rr.setRectXY(rect, 5, 5);
+                path->addRRect(rr, dir);
+                break;
+                }
+            case kOval_Shape:
+                path->addOval(rect, dir);
+                break;
+            default:
+                break;
+        }
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+
+        SkPaint shapePaint;
+        shapePaint.setColor(SK_ColorBLACK);
+        shapePaint.setAntiAlias(fDoAA);
+
+        SkRect outerRect = SkRect::MakeWH(40, 40);
+
+        SkRect innerRects[] = {
+            { 10, 10, 30, 30 },     // small
+            { .5f, 18, 4.5f, 22 }   // smaller and offset to left
+        };
+
+        // draw a background pattern to make transparency errors more apparent
+        SkMWCRandom rand;
+
+        for (int y = 0; y < kImageHeight; y += 10) {
+            for (int x = 0; x < kImageWidth; x += 10) {
+                SkRect r = SkRect::MakeXYWH(SkIntToScalar(x), 
+                                            SkIntToScalar(y), 
+                                            10, 10);
+                SkPaint p;
+                p.setColor(rand.nextU() | 0xFF000000);
+                canvas->drawRect(r, p);
+            }
+        }
+
+        canvas->translate(2, 2);
+        for (int outerShape = 0; outerShape < kShapeCount; ++outerShape) {
+            canvas->save();
+            for (int innerShape = 0; innerShape < kShapeCount; ++innerShape) {
+                for (size_t innerRect = 0; innerRect < SK_ARRAY_COUNT(innerRects); ++innerRect) {
+                    SkPath path;
+
+                    AddShape(&path, outerRect, (Shapes) outerShape, SkPath::kCW_Direction);
+                    AddShape(&path, innerRects[innerRect], (Shapes) innerShape, 
+                             SkPath::kCCW_Direction);
+
+                    canvas->drawPath(path, shapePaint);
+                    canvas->translate(45, 0);
+                }
+            }
+            canvas->restore();
+            canvas->translate(0, 45);
+        }
+
+    }
+
+private:
+    static const int kImageWidth = 269;
+    static const int kImageHeight = 134;
+
+    bool fDoAA;
+
+    typedef GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return new NestedGM(true); )
+DEF_GM( return new NestedGM(false); )
+
+
+}