Function measure_layout 

pub fn measure_layout(
    rasterizer: &TextRasterizer,
    root: &LayoutNode,
    time: MediaTime,
    size: PictureSize,
    canvas: (u32, u32),
) -> Result<LayoutBounds, TextRasterError>

Where each node of a valid layout tree lies on a picture of size at picture time time, laid out with rasterizer’s fonts exactly as a frame is.

canvas is the project canvas the tree’s pixel lengths refer to. Rects are layout boxes, before the clip’s transform and node visuals. An invalid tree gives unspecified rects but never panics.

Errors

Returns the text host’s refusal of a text: no fonts, or a size out of range.