Add gm to test SkRegion/clipPath bug.

Review URL: https://codereview.appspot.com/6501131

git-svn-id: http://skia.googlecode.com/svn/trunk@5540 2bbb7eff-a529-9590-31e7-b0007b416f81

gm/distantclip.cpp

@@ -0,0 +1,71 @@
+
+
+/*
+ * Copyright 2012 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 "SkCanvas.h"
+#include "SkPicture.h"
+
+namespace skiagm {
+
+class DistantClipGM : public GM {
+public:
+    DistantClipGM() { }
+
+protected:
+
+    SkString onShortName() {
+        return SkString("distantclip");
+    }
+
+    SkISize onISize() { return make_isize(100, 100); }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        int offset = 35000;
+        int extents = 1000;
+
+        // We record a picture of huge vertical extents in which we clear the canvas to red, create
+        // a 'extents' by 'extents' round rect clip at a vertical offset of 'offset', then draw
+        // green into that.
+        SkPicture pict;
+        SkCanvas* rec = pict.beginRecording(100, offset + extents);
+        rec->drawColor(0xffff0000);
+        rec->save();
+        SkRect r = {-extents, offset - extents, extents, offset + extents};
+        SkPath p;
+        p.addRoundRect(r, 5, 5);
+        rec->clipPath(p, SkRegion::kIntersect_Op, true);
+        rec->drawColor(0xff00ff00);
+        rec->restore();
+        pict.endRecording();
+
+        // Next we play that picture into another picture of the same size.
+        SkPicture pict2;
+        pict.draw(pict2.beginRecording(100, offset + extents));
+        pict2.endRecording();
+
+        // Finally we play the part of that second picture that should be green into the canvas.
+        canvas->save();
+        canvas->translate(extents / 2, -(offset - extents / 2));
+        canvas->drawPicture(pict2);
+        canvas->restore();
+
+        // If the image is red, we erroneously decided the clipPath was empty and didn't record
+        // the green drawColor, if it's green we're all good.
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new DistantClipGM; }
+static GMRegistry reg(MyFactory);
+
+}

gyp/gmslides.gypi

@@ -22,6 +22,7 @@
     '../gm/degeneratesegments.cpp',
     '../gm/dashcubics.cpp',
     '../gm/dashing.cpp',
+    '../gm/distantclip.cpp',
     '../gm/drawbitmaprect.cpp',
     '../gm/drawlooper.cpp',
     '../gm/extractbitmap.cpp',