#pixel-art #bevy #bitmap-font #gamedev #text-image #pixelart #bevy-plugin

bevy_pxtxt

Create fonts and render text in bevy based on a bitmap source image

5 releases

0.2.0 Jul 22, 2024
0.1.3 Jul 6, 2024
0.1.2 Jul 5, 2024
0.1.1 Jul 5, 2024
0.1.0 Jul 4, 2024

#273 in Game dev

MIT license

105KB
813 lines

Bevy Pxtxt

Call it what you want — "pixel font," "image font," "texture font," etc. Either way, this library has it. bevy_pxtxt allows users to create fonts and render text based on images they draw themself.

The images by default are .png files, but .bmp, .jpeg, .gif, or .tiff can be used with their corresponding feature flags.

Example

assets/moonshock.ron

(
    name: "Moonshock",
    image: "moonshock.png",
    glyph_width: Varied (
        max: 5,
        min: 1,
    ),
    spacing: 1,
    ascender: 7,
    descender: 2,
)

examples/sections.rs

use bevy::prelude::*;
use bevy_asset_loader::asset_collection::{AssetCollection, AssetCollectionApp};
use bevy_pxtxt::{plugin::PxtxtPlugin, pxfont::PxFont, pxtext::{PxText, PxTextBundle, PxTextSection}};

#[derive(AssetCollection, Resource)]
struct PxFontCollection {
    #[asset(path = "moonshock.ron")]
    pub moonshock: Handle<PxFont>,
}

fn main() {
    App::new()
        .add_plugins((DefaultPlugins, PxtxtPlugin::default()))
        .init_collection::<PxFontCollection>()
        .insert_resource(Msaa::Off)
        .add_systems(Startup, setup)
        .run();
}

fn setup(
    fonts: Res<PxFontCollection>,
    mut commands: Commands,
) {
    commands.spawn(Camera2dBundle::default());
    commands.spawn(PxTextBundle {
        text: PxText::from_sections(
            vec![
                PxTextSection::new("Here's a ")
                    .with_color(Color::WHITE),
                PxTextSection::new("c")
                    .with_color(Color::hsl(0., 0.9, 0.7)).underlined(),
                PxTextSection::new("o")
                    .with_color(Color::hsl(70., 0.9, 0.7)).underlined(),
                PxTextSection::new("l")
                    .with_color(Color::hsl(170., 0.9, 0.7)).underlined(),
                PxTextSection::new("o")
                    .with_color(Color::hsl(220., 0.9, 0.7)).underlined(),
                PxTextSection::new("r")
                    .with_color(Color::hsl(280., 0.9, 0.7)).underlined(),
                PxTextSection::new("ful example of some pixel text.\n\n")
                    .with_color(Color::WHITE),
                PxTextSection::new("(Using sections for different colors)")
                    .with_color(Color::GRAY),
            ], fonts.moonshock.clone()
        ).with_line_spacing(5),
        transform: Transform::from_scale(Vec3::splat(4.0)),
        ..Default::default()
    });
}

Result: Example result, reads "Here's a colorful example of some pixel text. (Using sections for different colors.)".

PxFontData Files

Fonts are loaded onto PxFonts, which uses PxFontData for deserialization. This is the struct that the .ron files write.

Required Fields:

  • name - the name of the font
  • image - the path to the image of the font, relative to the assets folder
  • glyph_width - width of each character
    • Varied - automatically detect the width of characters between a max and min value
    • Monospace - all characters are the same width
  • ascender - number of pixels above the base line
  • descender - number of pixels below the base line

Optional Fields:

  • char_layout - what characters are displayed on the image
    • StartingAt - the characters start at the given character and continue in order of ascending unicode value
    • Ranges - the characters are given as a series of ranges
    • Listed - the characters are individually listed
    • default: StartingAt(' ')
  • spacing - space between each character within a word
    • default: 1
  • padding - padding between characters in the image
    • default: (0, 0)

Input

Sections with can receive events for left clicks, right clicks, and hovering. PickableText senses these events, when the child of an entity with PxText.

To receive these events, use EventReader<PxTextEvent> (read up on events).

Examples

See examples/bounded.rs for how bounding boxes can be used.

See examples/picking.rs for how input can be used.

See examples/sections.rs (above as well) for how different sections can be used.

Compatibility

Bevy Pxtxt version 0.1 is comptabile with Bevy version 0.13.

License

This library, including the examples and assets, is licensed under the MIT License.

Dependencies

~39–76MB
~1.5M SLoC