// purplestamp

​

// Whether to use a separate bitmap (with a color type) at all.

bool drawWithRasterImage = true;

​

// This works with either kN32_SkColorType or kAlpha_8_SkColorType.

// Applies only if drawWithRasterImage is true.

SkColorType colorType = kN32_SkColorType;

​

void drawStamp(SkCanvas* canvas, int size) {

    canvas->save();

    canvas->clipRect(SkRect::MakeWH(size, size), SkClipOp::kIntersect, true);

​

    canvas->clear(0x3F000000 /* translucent black */);

​

    SkPaint paint;

    paint.setAntiAlias(true);

    paint.setColor(SK_ColorBLACK);

    canvas->drawRRect(

            SkRRect::MakeOval(SkRect::MakeXYWH(size / 4, size / 4, size / 2, size / 2)), paint);

​

    paint.setStyle(SkPaint::kStroke_Style);

    paint.setStrokeWidth(20);

    canvas->drawRect(SkRect::MakeWH(size, size), paint);

​

    canvas->restore();

}

​

sk_sp<SkImage> stampImage(int size) {

    sk_sp<SkSurface> surface =

            SkSurfaces::Raster(SkImageInfo::Make(size, size, colorType, kPremul_SkAlphaType));

    drawStamp(surface->getCanvas(), size);

    return surface->makeImageSnapshot();

}

​

void draw(SkCanvas* canvas) {

    SkPaint paint;

    paint.setColorFilter(SkColorFilters::Blend(0xFF7F00FF, SkBlendMode::kSrcIn));

    paint.setAntiAlias(true);

​

    SkSamplingOptions sampling(SkFilterMode::kLinear, SkMipmapMode::kLinear);

​

    canvas->rotate(30);

    canvas->translate(60, 0);

​

    int stampSize = 200;

    if (drawWithRasterImage) {

        canvas->drawImage(stampImage(stampSize), 0, 0, sampling, &paint);

    } else {

        canvas->saveLayer(nullptr, &paint);

        drawStamp(canvas, stampSize);

        canvas->restore();

    }

}