fit

Places content in a container like CSS object-fit and object-position, e.g. to show a design frame in a viewport of another size.

The result is the matrix from content coordinates to container coordinates: a and d are the scales, e and f the position of the content’s top-left corner. Map points with Matrix::apply, combine it with Matrix::multiply, or write it with Matrix::to_css. Sizes are expected to be positive.

Import

use helpers4::geometry::fit;

Cargo feature geometry (enabled by default). To compile only this module:

cargo add helpers4 --no-default-features --features geometry

or in Cargo.toml:

[dependencies]
helpers4 = { version = "0.0.9", default-features = false, features = ["geometry"] }

Signature

pub fn fit(content: Size, container: Size, mode: FitMode, align: FitAlign) -> Matrix

Parameters

Parameter	Type	Description
content	Size	The size of the content.
container	Size	The size of the container.
mode	FitMode	How to size the content.
align	FitAlign	Where to place it.

Returns

Matrix — The content-to-container matrix.

Examples

use helpers4::geometry::{fit, FitAlign, FitMode, Matrix, Size};

let m = fit(Size::new(200.0, 100.0), Size::new(100.0, 100.0), FitMode::Contain, FitAlign::CENTER);
assert_eq!(m, Matrix::new(0.5, 0.0, 0.0, 0.5, 0.0, 25.0));

let left = fit(Size::new(200.0, 100.0), Size::new(100.0, 100.0), FitMode::Cover, FitAlign::new(0.0, 0.5));
assert_eq!(left, Matrix::new(1.0, 0.0, 0.0, 1.0, 0.0, 0.0)); // cropped on the right

Source

src/geometry/fit.rs