Fonts

• embedded-graphics monospace: Fixed-width fonts from the embedded-graphics crate, perfect for simple displays and consistent spacing.

• U8g2: A rich collection of fonts ported from the U8g2 library, offering more variety in styles and sizes.

• RustType: Display common font formats (.otf, .ttf) through the rusttype crate for high-quality text rendering, support for variable sizing, and hinted antialiasing.

Supported Features

Precise Bounds

By default, Buoyant will lay out text such that adjacent Text views in HStacks and VStacks are consistently spaced and aligned regardless of their content. This is achieved by extending the view width by the last glyph’s advance, and the height by the line spacing.

However, you may want the view’s bounds to tightly fit the actual drawn pixels of the text, such as when adding backgrounds or borders to text. In this case, you can enable precise bounds:

#![allow(unused)]
fn main() {
extern crate buoyant;
extern crate u8g2_fonts;
use buoyant::view::prelude::*;
use u8g2_fonts::{fonts, FontRenderer};

static HELVETICA: FontRenderer = FontRenderer::new::<fonts::u8g2_font_helvR12_tr>();

Text::new("Buoyant", &HELVETICA)
    .with_precise_bounds()
;
}

Variable Sizing

Fonts which have no intrinsic size, such as TrueType fonts, can be rendered at variable sizes using the .with_font_size(pts) modifier:

Text::new("hello", &TTF_FONT)
   .with_font_size(22)

If no size is specified, a default size (12pt) will be used.

Hinted Antialiasing

Buoyant supports hinted antialiased rendering which differs from standard antialiasing in that a background color must be provided to allow the render target to blend edges. The actual underlying pixels are not read.

The hint can be set several ways, including:

• Using the .hint_background_color(color) modifier, to manually specify a background color on a view subtree,
• Using the .background_color(color, shape) modifier, which renders a shape with the specified fill color behind the view, automatically setting the hint, or
• Providing a hint when initializing the render target, such as EmbeddedGraphicsRenderTarget::new_hinted(&mut display, color);.

Setting a hint is not required, and text will render without antialiasing if no hint is provided.