Freehand

Freehand is a small Rust library with minimal dependencies that provides extra drawing utilities that utilize the image crate.

Why?

• Only depends on the image crate.
• Provides some additional drawing functions not found in the imageproc (which also has many dependencies).

Drawing

It provides the following for drawing:

• circular arcs
• partial annulii (basically a slice of a filled donut)
• antialiased circular arcs
• straight vertical, horizontal, and diagonal lines, with variants for dashed lines and alpha blended lines
• filled rectangles

Usage

The image crate should already be a dependency, as this crate operates on its image types.

1. Add freehand to your Cargo.toml's dependencies:

   [dependencies]
   freehand = "0.1.0"

2. Choose to either use the Draw struct, for convenience methods, or the regular funcitons (the Draw struct methods are recommended, but do not include methods for the more specific diagonal, vertical, or horizontal line functions).

   // no `use` statements required here
   // just pass in the image you wish to work on
   # let mut image = image::RgbaImage::new(400, 400);
   let draw = freehand::new(&mut image);
   
   let red = image::Rgba([255, 0, 0, 255]);
   
   // draws a line diagonally across an a 400x400 pixel image in red
   draw.line((0, 0), (399,399), red);

Notes

Angles

Angles are treated differently based on their type. Floating-point types will be in radians, while integer types will be treated as degrees (and silently converted to radians).

Opacity

Anti-aliasing and alpha blending functions currently only work with RgbaImages.

Also note functions that have an explicit opacity parameter will not take an Rgba value's alpha channel into account when blending (unless stated otherwise).

Serde

If you wish to serialize/deserialize the available structs specify the serde feature in your Cargo.toml:

[dependencies]
freehand = { version = "0.1.0", features = ["serde"]}

Limitations

Currently antialiasing and alpha blending are only supported when using an RgbaImage image.

Todo

• Add more shapes
• Add elliptical arcs

License

Apache-2.0 OR MIT