Crate kaku

A font rendering crate for rendering text using signed distance fields.

This crate aims to provide a general and easy to use API for rendering text using wgpu. It can render text normally (using raster images), or with signed distance fields, which allows for performant scaling and outlining.

Usage

Here is an example of how to use the crate. You first need to create a TextRenderer struct, then load a font using ab_glyph, then you can create a Text object, which is the thing that can be drawn.

let mut text_renderer =
    TextRendererBuilder::new(target_format, target_size).build(&device);
     
let font = ab_glyph::FontRef::try_from_slice(include_bytes!("FiraSans-Regular.ttf"))?;
let font = text_renderer.load_font_with_sdf(font, 45., SdfSettings { radius: 15. });

let text = TextBuilder::new("Hello, world!", font, [100., 100.])
    .outlined([1.; 4], 10.)
    .build(&device, &queue, &mut text_renderer);

You can then draw this text object during a render pass like so:

text_renderer.draw(&mut render_pass, &text);

Performance

Calculating the signed distance field for a character takes a small but not-insignificant amount of time. This will only happen once for each character in a font, and can be done ahead of time using TextRenderer::generate_char_textures, but is still a cost. If you don’t need the features provided by sdf rendering, you should use non-sdf rendering instead.

Re-exports

pub use ab_glyph;

Structs

FontId

A handle to a font stored in the TextRenderer.

SdfSettings

Settings for how the signed distance field calculation should work for a font.

Text

A piece of text that can be rendered to the screen.

TextBuilder

A builder for a Text struct.

TextRenderer

The main struct that handles text rendering to the screen. Use this struct to load fonts and draw text during a render pass.

TextRendererBuilder

A builder for a TextRenderer struct.

Enums

FontSize

Settings for font size.

HorizontalAlignment

Settings for horizontal text alignment

VerticalAlignment

Settings for vertical text alignment.