Skia Fiddle

Options

Width Height

check_box_outline_blank check_box Text Only [Use SkDebugf()]

check_box_outline_blank check_box sRGB

check_box_outline_blank check_box F16

check_box_outline_blank check_box Animation

check_box_outline_blank check_box Offscreen Render Target

Width Height Sample Count

check_box_outline_blank check_box Texturable

check_box_outline_blank check_box MipMap

This global is now defined:

GrBackendRenderTarget backEndRenderTarget;

GrBackendTexture backEndTextureRenderTarget;

Optional source image

check_box_outline_blank check_box MipMap

These globals are now defined:

SkBitmap source;
sk_sp<SkImage> image;
GrBackendTexture backEndTexture; // GPU Only.

Note:

Adding comments with SK_FOLD_START and SK_FOLD_END creates foldable code blocks.
These blocks will be folded by default and are useful for highlighting specific lines of code.
You can also use the keyboard shortcuts Ctrl+S and Ctrl+E in the code editor to set them.

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void draw(SkCanvas* canvas) {
    auto radiusToSigma = [](SkScalar radius) -> SkScalar {
         static const SkScalar kBLUR_SIGMA_SCALE = 0.57735f;
         return radius > 0 ? kBLUR_SIGMA_SCALE * radius + 0.5f : 0.0f;
    };
    SkBitmap alpha, bitmap;
    bitmap.allocN32Pixels(100, 100);
    SkCanvas offscreen(bitmap);
    offscreen.clear(0);
    SkPaint paint;
    paint.setAntiAlias(true);
    paint.setColor(SK_ColorBLUE);
    paint.setStyle(SkPaint::kStroke_Style);
    paint.setStrokeWidth(20);
    offscreen.drawCircle(50, 50, 39, paint);
    paint.setMaskFilter(SkMaskFilter::MakeBlur(kNormal_SkBlurStyle, radiusToSigma(25)));
    SkIPoint offset;
    bitmap.extractAlpha(&alpha, &paint, &offset);
    paint.setColor(SK_ColorRED);
    canvas->drawImage(bitmap.asImage(), 0, -offset.fY, SkSamplingOptions(), &paint);
    canvas->drawImage(alpha.asImage(), 100 + offset.fX, 0, SkSamplingOptions(), &paint);
}