Struct Bitmap 

pub struct Bitmap {
    pub width: u32,
    pub height: u32,
    pub pixels: Vec<u8>,
}

A greyscale glyph bitmap.

Fields

width: u32

Width in pixels.

height: u32

Height in pixels.

pixels: Vec<u8>

Pixel data, one byte per pixel (0 = transparent, 255 = fully opaque).

Implementations

impl Bitmap

pub fn is_empty(&self) -> bool

Returns true if the bitmap has zero area (no visible pixels), as is the case for whitespace glyphs.

pub fn invert_coverage(&self) -> Self

Invert the coverage values (255 - x) for use in inside/outside SDF generation.

Coverage bitmaps from rasterizers use 255 = opaque, 0 = transparent. Some SDF algorithms expect the inverse convention where 0 = inside the glyph outline. This method produces a new bitmap with all values flipped.

pub fn threshold(&self, threshold: u8) -> Self

Return a copy with pixels below the threshold set to 0, above (or equal) to 255.

Useful for binarizing a greyscale coverage map before Euclidean Distance Transform (EDT) so that only fully-inside and fully-outside pixels are distinguished.

pub fn crop(&self, x: u32, y: u32, width: u32, height: u32) -> Self

Return a cropped sub-bitmap starting at pixel (x, y) with the given width and height. Out-of-bounds source regions are filled with 0.

pub fn tight_bounds(&self) -> Option<(u32, u32, u32, u32)>

Return the minimum bounding box of non-zero pixels, useful for tight SDF tile sizing and atlas packing.

Returns (x_min, y_min, x_max, y_max) in pixel coordinates, or None if the bitmap contains no non-zero pixels (e.g. a space glyph).

Trait Implementations

impl Clone for Bitmap

fn clone(&self) -> Bitmap

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Bitmap

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.