Function render_element 

pub fn render_element<Msg>(
    el: Element<Msg>,
    theme: &Theme,
    size: (u32, u32),
) -> RgbaImage

Renders an element tree headlessly at scale factor 1.0 over the theme background, using only the embedded fonts for determinism. This is fenestra’s product thesis: agents render what they build and look at it.

The requested size is clamped to the device-supported range (at least 1x1, at most the maximum texture dimension, typically 8192); check the returned image’s dimensions when the input may be out of range.

Panics

If no compute-capable GPU adapter exists or rendering fails.