Function rsvg::filters::gaussian_blur::three_box_blurs

fn three_box_blurs<B: BlurDirection>(
    surface: &SharedImageSurface,
    bounds: IRect,
    std_deviation: f64
) -> Result<SharedImageSurface, FilterError>

Applies three box blurs to approximate the gaussian blur.

This is intended to be used in two steps, horizontal and vertical.