bevy/crates/bevy_text/src/lib.rs
JoJoJet 456971381c Resolve most remaining execution-order ambiguities (#6341)
# Objective

Bevy's internal plugins have lots of execution-order ambiguities, which makes the ambiguity detection tool very noisy for our users.

## Solution

Silence every last ambiguity that can currently be resolved.
Each time an ambiguity is silenced, it is accompanied by a comment describing why it is correct. This description should be based on the public API of the respective systems. Thus, I have added documentation to some systems describing how they use some resources.

# Future work

Some ambiguities remain, due to issues out of scope for this PR. 

* The ambiguity checker does not respect `Without<>` filters, leading to false positives.
* Ambiguities between `bevy_ui` and `bevy_animation` cannot be resolved, since neither crate knows that the other exists. We will need a general solution to this problem.
2022-10-27 12:56:03 +00:00

99 lines
3.1 KiB
Rust

mod error;
mod font;
mod font_atlas;
mod font_atlas_set;
mod font_loader;
mod glyph_brush;
mod pipeline;
mod text;
mod text2d;
pub use error::*;
pub use font::*;
pub use font_atlas::*;
pub use font_atlas_set::*;
pub use font_loader::*;
pub use glyph_brush::*;
pub use pipeline::*;
pub use text::*;
pub use text2d::*;
pub mod prelude {
#[doc(hidden)]
pub use crate::{
Font, HorizontalAlign, Text, Text2dBundle, TextAlignment, TextError, TextSection,
TextStyle, VerticalAlign,
};
}
use bevy_app::prelude::*;
use bevy_asset::AddAsset;
use bevy_ecs::{schedule::IntoSystemDescriptor, system::Resource};
use bevy_render::{camera::CameraUpdateSystem, RenderApp, RenderStage};
use bevy_sprite::SpriteSystem;
use bevy_window::ModifiesWindows;
use std::num::NonZeroUsize;
#[derive(Default)]
pub struct TextPlugin;
/// [`TextPlugin`] settings
#[derive(Resource)]
pub struct TextSettings {
/// Maximum number of font atlases supported in a ['FontAtlasSet']
pub max_font_atlases: NonZeroUsize,
/// Allows font size to be set dynamically exceeding the amount set in max_font_atlases.
/// Note each font size has to be generated which can have a strong performance impact.
pub allow_dynamic_font_size: bool,
}
impl Default for TextSettings {
fn default() -> Self {
Self {
max_font_atlases: NonZeroUsize::new(16).unwrap(),
allow_dynamic_font_size: false,
}
}
}
/// Text is rendered for two different view projections, normal `Text2DBundle` is rendered with a
/// `BottomToTop` y axis, and UI is rendered with a `TopToBottom` y axis. This matters for text because
/// the glyph positioning is different in either layout.
pub enum YAxisOrientation {
TopToBottom,
BottomToTop,
}
impl Plugin for TextPlugin {
fn build(&self, app: &mut App) {
app.add_asset::<Font>()
.add_asset::<FontAtlasSet>()
.register_type::<Text>()
.register_type::<TextSection>()
.register_type::<Vec<TextSection>>()
.register_type::<TextStyle>()
.register_type::<TextAlignment>()
.register_type::<VerticalAlign>()
.register_type::<HorizontalAlign>()
.init_asset_loader::<FontLoader>()
.init_resource::<TextSettings>()
.insert_resource(TextPipeline::default())
.add_system_to_stage(
CoreStage::PostUpdate,
update_text2d_layout
.after(ModifiesWindows)
// Potential conflict: `Assets<Image>`
// In practice, they run independently since `bevy_render::camera_update_system`
// will only ever observe its own render target, and `update_text2d_layout`
// will never modify a pre-existing `Image` asset.
.ambiguous_with(CameraUpdateSystem),
);
if let Ok(render_app) = app.get_sub_app_mut(RenderApp) {
render_app.add_system_to_stage(
RenderStage::Extract,
extract_text2d_sprite.after(SpriteSystem::ExtractSprites),
);
}
}
}