skia2/gm/canvasstate.cpp

179 lines
4.8 KiB
C++

/*
* 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 "SkCanvas.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkRect.h"
namespace skiagm {
/*
* This GM exercises the flags to SkCanvas::save(). The canvas' save() and
* restore actions can be limited to only a portion of the canvas' state through
* the use of flags when calling save.
*/
class CanvasStateGM : public GM {
SkSize fSize;
enum {
WIDTH = 150,
HEIGHT = 150,
};
SkPaint fFillPaint;
SkPaint fStrokePaint;
SkPath fPath;
SkRect fOutlineRect;
SkRect fFillRect;
public:
CanvasStateGM() {
fSize.set(SkIntToScalar(WIDTH), SkIntToScalar(HEIGHT));
fFillPaint.setColor(SK_ColorRED);
fFillPaint.setStyle(SkPaint::kFill_Style);
fStrokePaint.setColor(SK_ColorBLUE);
fStrokePaint.setStyle(SkPaint::kStroke_Style);
fStrokePaint.setStrokeWidth(1);
fPath.moveTo(25, 25);
fPath.lineTo(125, 25);
fPath.lineTo(75, 125);
fPath.close();
fOutlineRect = SkRect::MakeXYWH(1, 1, WIDTH-2, HEIGHT-2);
fFillRect = SkRect::MakeXYWH(10, 10, WIDTH-20, HEIGHT-20);
}
protected:
virtual SkString onShortName() SK_OVERRIDE {
return SkString("canvas-state");
}
virtual SkISize onISize() SK_OVERRIDE {
return SkISize::Make(WIDTH*3, HEIGHT*4);
}
virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
SkCanvas::SaveFlags flags[] = { SkCanvas::kMatrix_SaveFlag,
SkCanvas::kClip_SaveFlag,
SkCanvas::kMatrixClip_SaveFlag };
// columns -- flags
// rows -- permutations of setting the clip and matrix
for (size_t i = 0; i < SK_ARRAY_COUNT(flags); ++i) {
for (int j = 0; j < 2; ++j) {
for (int k = 0; k < 2; ++k) {
this->drawTestPattern(i, (2*j)+k, canvas, flags[i],
SkToBool(j), SkToBool(k));
}
}
}
}
virtual uint32_t onGetFlags() const SK_OVERRIDE { return kSkipPicture_Flag; }
private:
void drawTestPattern(int x, int y, SkCanvas* canvas,
SkCanvas::SaveFlags flags, bool doClip, bool doScale) {
canvas->save();
canvas->translate(SkIntToScalar(x*WIDTH), SkIntToScalar(y*HEIGHT));
canvas->drawRect(fOutlineRect, fStrokePaint);
canvas->save(flags);
if(doClip) {
canvas->clipPath(fPath);
}
if (doScale) {
canvas->scale(SkDoubleToScalar(0.5), SkDoubleToScalar(0.5));
}
canvas->restore();
canvas->drawRect(fFillRect, fFillPaint);
canvas->restore();
}
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
class CanvasLayerStateGM : public GM {
public:
CanvasLayerStateGM() {
fBluePaint.setColor(SK_ColorBLUE);
fBluePaint.setStyle(SkPaint::kFill_Style);
fRect = SkRect::MakeXYWH(SPACER, SPACER, WIDTH-(2*SPACER), (HEIGHT-(2*SPACER)) / 7);
}
protected:
virtual SkString onShortName() SK_OVERRIDE {
return SkString("canvas-layer-state");
}
virtual SkISize onISize() SK_OVERRIDE {
return SkISize::Make(WIDTH, HEIGHT);
}
virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
// clear the canvas to red
canvas->drawColor(SK_ColorRED);
// both rects should appear
drawTestPattern(canvas, 255, SkCanvas::kARGB_NoClipLayer_SaveFlag);
canvas->translate(0, 2*(fRect.height() + 10));
// only the top rect should appear
drawTestPattern(canvas, 255, SkCanvas::kARGB_ClipLayer_SaveFlag);
canvas->translate(0, 2*(fRect.height() + 10));
// only the bottom rect should appear
drawTestPattern(canvas, 0, SkCanvas::kARGB_NoClipLayer_SaveFlag);
}
virtual uint32_t onGetFlags() const SK_OVERRIDE { return kSkipGPU_Flag; }
private:
// draw a rect within the layer's bounds and again outside the layer's bounds
void drawTestPattern(SkCanvas* canvas, U8CPU layerAlpha, SkCanvas::SaveFlags flags) {
canvas->saveLayerAlpha(&fRect, layerAlpha, flags);
canvas->drawRect(fRect, fBluePaint);
canvas->translate(0, fRect.height() + 10);
canvas->drawRect(fRect, fBluePaint);
canvas->restore();
}
enum {
WIDTH = 400,
HEIGHT = 400,
SPACER = 10,
};
SkPaint fBluePaint;
SkRect fRect;
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_GM( return SkNEW(CanvasStateGM); )
DEF_GM( return SkNEW(CanvasLayerStateGM); )
} // end namespace