Module blend 

Pixel arithmetic.

Everything here is integer. There is no f32 in the rasteriser at all, which buys three things: no libm dependency in a no_std build, no FPU traffic on targets where that is expensive, and — most usefully — output that is bit-identical on x86 and ARM, so a golden-image test is a meaningful test.

Structs

Paint

A colour prepared for drawing.

Functions

blend_pixel

Composites a paint over a single pixel at coverage (0..=255).

blend_span

Composites a constant paint over a span.

fill_span

Overwrites a span with an opaque word.

premultiply

Premultiplies straight-alpha 0xAARRGGBB words in place.

scale_premul

Scales a premultiplied 0xAARRGGBB word — alpha lane included — by a coverage of 0..=255.

source_over

Composites a premultiplied source over a destination pixel.