void draw(SkCanvas* canvas) {

    // Default SkPaint properties

    SkPaint p;

    p.setAntiAlias(true);

    p.setStyle(SkPaint::kFill_Style);

    p.setStrokeWidth(10);

​

    // Draw red squares

    p.setColor(SK_ColorRED);

    const SkRect red = SkRect::MakeXYWH(0, 0, 128, 128);

    canvas->drawRect(red, p);

    const SkRect red2 = SkRect::MakeXYWH(128, 128, 128, 128);

    canvas->drawRect(red2, p);

    // Draw blue squares

    p.setColor(SK_ColorBLUE);

    const SkRect blue = SkRect::MakeXYWH(128, 0, 128, 128);

    canvas->drawRect(blue, p);

    const SkRect blue2 = SkRect::MakeXYWH(0, 128, 128, 128);

    canvas->drawRect(blue2, p);

​

    // Create middle overlay rectangle for background blur

    const SkRect middle = SkRect::MakeXYWH(64, 64, 128, 128);

​

    // Use middle rectangle as clip mask

    canvas->clipRect(middle, true);

​

    // Two blur filters, one that we're currently using and the newer one in current version of Skia.

    // Both blur filters select a tile mode for clamping the blur filter at the rectangle's edges.

    // However, the result on the CPU does NOT appear to clamp at all, while the result on GPU does!

    sk_sp<SkImageFilter> oldBlurFilter = SkBlurImageFilter::Make(25, 25, nullptr, nullptr, SkBlurImageFilter::kClamp_TileMode);

    sk_sp<SkImageFilter> newBlurFilter = SkImageFilters::Blur(25, 25, SkTileMode::kClamp, nullptr);

​

    p.setImageFilter(std::move(oldBlurFilter));

​

    // Make a separate layer using the blur filter, clipped to the middle rectangle's bounds

    SkCanvas::SaveLayerRec slr(&middle, &p, SkCanvas::kInitWithPrevious_SaveLayerFlag);

    canvas->saveLayer(slr);

​

    // Fill the clip middle rectangle with a transparent white

    canvas->drawColor(0x40FFFFFF);

    canvas->restore();

}