Struct Headless 

pub struct Headless { /* private fields */ }

A reusable offscreen renderer. Creating one compiles vello’s shaders, so tests should create it once and render many scenes through it.

Implementations

impl Headless

pub fn new() -> Result<Self, ShellError>

Acquires a compute-capable adapter (no surface required) and builds a vello renderer on it.

pub fn max_dimension(&self) -> u32

The largest texture dimension the device supports; render sizes are clamped to it.

pub fn clamp_size(&self, width: u32, height: u32) -> (u32, u32)

Clamps a requested render size on both axes to the supported 1..=max_dimension() range.

pub fn render( &mut self, scene: &Scene, width: u32, height: u32, base_color: Color, ) -> Result<RgbaImage, ShellError>

Renders scene at the given pixel size over base_color and reads the result back into an RGBA image. The size is clamped to 1..=max_dimension() on both axes, so hostile dimensions cannot trigger wgpu’s fatal validation handler.