Struct CpuSurface 

pub struct CpuSurface { /* private fields */ }

A surface’s frames kept in memory and drawn on the CPU: what a host shows on a machine where the toolkit has no GPU adapter to draw them on, exactly as it draws a normal app’s frame there. Kept between frames, so damage costs only what it changed.

Implementations

impl CpuSurface

pub fn new(width: u32, height: u32, threads: u16) -> Option<CpuSurface>

A surface of width x height pixels, rasterized with up to threads cores, or None where this build has no CPU rasterizer.

pub const fn size(&self) -> (u32, u32)

Its size in pixels.

pub fn pixels(&self) -> &[u8]

The pixels drawn last, premultiplied RGBA, width * 4 bytes a row.

pub fn draw( &mut self, scene: &Scene, damage: Option<&[(u32, u32, u32, u32)]>, ) -> Option<Vec<(u32, u32, u32, u32)>>

Draw scene (physical pixels) over the pixels already here, in the damage regions of the surface as (x, y, width, height); the first draw covers all of it, and a surface draws nothing outside its own pixels. Returns the regions drawn, or None where no pixel changed.

The regions drawn are the ones this rasterizer saw its prepared scenes differ in ([tilo_cpu_raster::CpuRasterizer::changes]): the pixels are its own and it keeps the frame before, so it proves what a caller cannot, more finely than damage says and for nothing when nothing changed. Pixels that only moved, as they do in a strip that slides, are moved rather than drawn. damage is what the caller knows of the change, drawn where that proof is too large to list, and a change listed in more places than [MAX_REGIONS] is drawn in the region they cover.