3 unstable releases
0.2.0 | Aug 3, 2021 |
---|---|
0.1.1 | Jan 4, 2021 |
0.1.0 | Oct 10, 2020 |
#757 in Game dev
225KB
398 lines
Bevy SVG map
Crate for loading SVG files directly into bevy. The properties of the lines (color, opacity, fill…) can be used to programmatically add functionality, setting the foundation for a very weird workflow: Vector Graphics as editor to bevy entities!
If you are looking for a plugin that loads SVGs, you may want to take a look at bevy_svg.
Getting started
Add the library to your project's Cargo.toml
(check last published version,
it corresponds to the stable version on the branch crates.io
):
[dependencies]
bevy_svg_map = "0.2"
If you want the bleeding edge (corresponds to master
):
[dependencies]
bevy_svg_map = {git="https://github.com/carrascomj/bevy_svg_map.git"}
⚠️ The master branch points to each master branch of bevy. Use with caution!
The library provides a function to be used inside a bevy's startup_system.
Here, we are loading the file ex.svg
under the assets/
directory.
use bevy_svg_map::load_svg_map;
use bevy::prelude::*;
// We need to provide a struct implementing the StyleStrategy
// leave it as default, we'll come back to this later
struct MyStrategy;
impl StyleStrategy for MyStrategy {}
fn main() {
App::build()
.add_default_plugins()
.add_startup_system(setup.system())
.run();
}
fn setup(mut com: Commands, mat: ResMut<Assets<ColorMaterial>>, mesh: ResMut<Assets<Mesh>>) {
load_svg_map(com, mat, mesh, "assets/ex.svg", MyStrategy);
}
That should display some lines as in the image on the top. However, they are plain
black (default for StyleStrategy
). What about using the colors from the SVG
path strokes?
// we're now also using SvgStyle
use bevy_svg_map::{load_svg_map, StyleStrategy, SvgStyle};
use bevy::prelude::*;
struct MyStrategy;
impl StyleStrategy for MyStrategy {
// implement this trait method
fn color_decider(&self, style: &SvgStyle) -> Color {
match style.stroke() {
Some(c) => c,
// add red lines if the Color could not be parsed from the SVG
_ => Color::RED,
}
}
}
OK, that's a bit more interesting. Notice how SvgStyle
exposes properties of
the style of the SVG path. For each of these paths, the color_decider
function is applied to… well… decide its color.
Finally, to provide some actually interesting functionality, we can apply arbitrary functions to each component created from the path.
// ... same as before
use bevy::ecs::system::EntityCommands;
// This Component will be added to each SpriteComponents created from a path
enum Collider {
Scorable,
Solid,
}
impl StyleStrategy for MyStrategy {
// implement this trait method
fn color_decider(&self, style: &SvgStyle) -> Color {
// same as before
}
fn component_decider(&self, style: &SvgStyle, mut comp: EntityCommands) {
// use the stroke opacity to decide the kind of Collider
comp.insert(
if style.stroke_opacity().unwrap() == 1.0 {
Collider::Solid
} else{
Collider::Scorable
}
);
}
}
Check out more properties to extract from SvgStyle
in the documentation!
Troubleshooting
- Set up your Document Properties (in Inkscape Ctrl+Shift+D) to pixels so that you get the right world units.
- See this comment about setting SVG output.
Features
- Load Horizontal and Vertical lines.
- Load other types of svgtypes
PathSegment
s. - Provide a strategy trait to use the style to add Components and materials.
- Basic shapes.
- Handling of units.
Dependencies
~17–26MB
~428K SLoC