skia2/gm/distantclip.cpp
2016-09-20 08:42:39 -07:00

73 lines
2.3 KiB
C++

/*
* 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"
#include "SkPictureRecorder.h"
namespace skiagm {
class DistantClipGM : public GM {
public:
DistantClipGM() { }
protected:
SkString onShortName() {
return SkString("distantclip");
}
SkISize onISize() { return SkISize::Make(100, 100); }
virtual void onDraw(SkCanvas* canvas) {
constexpr SkScalar kOffset = 35000.0f;
constexpr SkScalar kExtents = 1000.0f;
SkPictureRecorder recorder;
// 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.
SkCanvas* rec = recorder.beginRecording(kExtents, kOffset + kExtents, nullptr, 0);
rec->drawColor(SK_ColorRED);
rec->save();
SkRect r = SkRect::MakeXYWH(-kExtents, kOffset - kExtents, 2 * kExtents, 2 * kExtents);
SkPath p;
p.addRoundRect(r, 5, 5);
rec->clipPath(p, SkCanvas::kIntersect_Op, true);
rec->drawColor(SK_ColorGREEN);
rec->restore();
sk_sp<SkPicture> pict(recorder.finishRecordingAsPicture());
// Next we play that picture into another picture of the same size.
pict->playback(recorder.beginRecording(pict->cullRect().width(),
pict->cullRect().height(),
nullptr, 0));
sk_sp<SkPicture> pict2(recorder.finishRecordingAsPicture());
// Finally we play the part of that second picture that should be green into the canvas.
canvas->save();
canvas->translate(kExtents / 2, -(kOffset - kExtents / 2));
pict2->playback(canvas);
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);
}