bevy/crates/bevy_render/src/camera/camera.rs
TheRawMeatball a880b54508
Make EventReader a SystemParam (#1244)
* Add generic support for `#[derive(SystemParam)]`
* Make EventReader a SystemParam
2021-01-18 22:23:30 -08:00

73 lines
2.3 KiB
Rust

use super::CameraProjection;
use bevy_app::prelude::EventReader;
use bevy_ecs::{Added, Component, Entity, Query, QuerySet, Res};
use bevy_math::Mat4;
use bevy_reflect::{Reflect, ReflectComponent};
use bevy_window::{WindowCreated, WindowId, WindowResized, Windows};
#[derive(Default, Debug, Reflect)]
#[reflect(Component)]
pub struct Camera {
pub projection_matrix: Mat4,
pub name: Option<String>,
#[reflect(ignore)]
pub window: WindowId,
#[reflect(ignore)]
pub depth_calculation: DepthCalculation,
}
#[derive(Debug)]
pub enum DepthCalculation {
Distance,
ZDifference,
}
impl Default for DepthCalculation {
fn default() -> Self {
DepthCalculation::Distance
}
}
pub fn camera_system<T: CameraProjection + Component>(
mut window_resized_events: EventReader<WindowResized>,
mut window_created_events: EventReader<WindowCreated>,
windows: Res<Windows>,
mut queries: QuerySet<(
Query<(Entity, &mut Camera, &mut T)>,
Query<Entity, Added<Camera>>,
)>,
) {
let mut changed_window_ids = Vec::new();
// handle resize events. latest events are handled first because we only want to resize each window once
for event in window_resized_events.iter().rev() {
if changed_window_ids.contains(&event.id) {
continue;
}
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 window_created_events.iter().rev() {
if changed_window_ids.contains(&event.id) {
continue;
}
changed_window_ids.push(event.id);
}
let mut added_cameras = vec![];
for entity in &mut queries.q1().iter() {
added_cameras.push(entity);
}
for (entity, mut camera, mut camera_projection) in queries.q0_mut().iter_mut() {
if let Some(window) = windows.get(camera.window) {
if changed_window_ids.contains(&window.id()) || added_cameras.contains(&entity) {
camera_projection.update(window.width(), window.height());
camera.projection_matrix = camera_projection.get_projection_matrix();
camera.depth_calculation = camera_projection.depth_calculation();
}
}
}
}