bevy/crates/bevy_render/src/camera/camera.rs
2020-07-16 18:47:51 -07:00

87 lines
2.6 KiB
Rust

use super::CameraProjection;
use bevy_ecs::{Component, Local, Query, Res};
use bevy_math::Mat4;
use bevy_property::Properties;
use bevy_window::{WindowCreated, WindowReference, WindowResized, Windows};
use bevy_app::prelude::{Events, EventReader};
#[derive(Default, Debug, Properties)]
pub struct Camera {
pub projection_matrix: Mat4,
pub name: Option<String>,
#[property(ignore)]
pub window: WindowReference,
}
#[derive(Default)]
pub struct CameraSystemState {
window_resized_event_reader: EventReader<WindowResized>,
window_created_event_reader: EventReader<WindowCreated>,
}
pub fn camera_system<T: CameraProjection + Component>(
mut state: Local<CameraSystemState>,
window_resized_events: Res<Events<WindowResized>>,
window_created_events: Res<Events<WindowCreated>>,
windows: Res<Windows>,
mut query: Query<(&mut Camera, &mut T)>,
) {
let mut changed_window_ids = Vec::new();
let mut changed_primary_window_id = None;
// handle resize events. latest events are handled first because we only want to resize each window once
for event in state
.window_resized_event_reader
.iter(&window_resized_events)
.rev()
{
if changed_window_ids.contains(&event.id) {
continue;
}
if event.is_primary {
changed_primary_window_id = Some(event.id);
} else {
changed_window_ids.push(event.id);
}
}
// handle resize events. latest events are handled first because we only want to resize each window once
for event in state
.window_created_event_reader
.iter(&window_created_events)
.rev()
{
if changed_window_ids.contains(&event.id) {
continue;
}
if event.is_primary {
changed_primary_window_id = Some(event.id);
} else {
changed_window_ids.push(event.id);
}
}
for (mut camera, camera_projection) in &mut query.iter() {
if let Some(window) = match camera.window {
WindowReference::Id(id) => {
if changed_window_ids.contains(&id) {
windows.get(id)
} else {
None
}
}
WindowReference::Primary => {
if let Some(id) = changed_primary_window_id {
windows.get(id)
} else {
None
}
}
} {
camera_projection.update(window.width as usize, window.height as usize);
camera.projection_matrix = camera_projection.get_projection_matrix();
}
}
}