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) {
    std::vector<int32_t> srcPixels;
    srcPixels.resize(source.height() * source.rowBytes());
    SkPixmap pixmap(SkImageInfo::MakeN32Premul(source.width(), source.height()),
                    &srcPixels.front(), source.rowBytes());
    source.readPixels(pixmap, 0, 0);
    for (int y = 0; y < 16; ++y) {
        for (int x = 0; x < 16; ++x) {
            int32_t* blockStart = &srcPixels.front() + y * source.width() * 16 + x * 16;
            size_t transparentCount = 0;
            for (int fillY = 0; fillY < source.height() / 16; ++fillY) {
                for (int fillX = 0; fillX < source.width() / 16; ++fillX) {
                    const SkColor color = SkUnPreMultiply::PMColorToColor(blockStart[fillX]);
                    transparentCount += SkColorGetA(color) == SK_AlphaTRANSPARENT;
                }
                blockStart += source.width();
            }
            if (transparentCount > 200) {
                blockStart = &srcPixels.front() + y * source.width() * 16 + x * 16;
                for (int fillY = 0; fillY < source.height() / 16; ++fillY) {
                    for (int fillX = 0; fillX < source.width() / 16; ++fillX) {
                        blockStart[fillX] = SK_ColorRED;
                    }
                    blockStart += source.width();
                }
            }
        }
    }
    canvas->drawImage(SkImages::RasterFromPixmapCopy(pixmap), 0, 0);
}