Files
bevy_oxr/crates/bevy_xr/src/camera.rs
2025-01-17 05:45:01 +01:00

109 lines
3.6 KiB
Rust

use core::panic;
use bevy::app::{App, Plugin, PostUpdate};
use bevy::core_pipeline::core_3d::Camera3d;
use bevy::ecs::component::{Component, StorageType};
use bevy::ecs::reflect::ReflectComponent;
use bevy::ecs::schedule::IntoSystemConfigs;
use bevy::math::{Mat4, Vec3A};
use bevy::pbr::{PbrPlugin, PbrProjectionPlugin};
use bevy::prelude::Projection;
use bevy::reflect::std_traits::ReflectDefault;
use bevy::reflect::Reflect;
use bevy::render::camera::{CameraProjection, CameraProjectionPlugin};
use bevy::render::extract_component::{ExtractComponent, ExtractComponentPlugin};
use bevy::render::view::{update_frusta, VisibilitySystems};
use bevy::transform::TransformSystem;
use crate::session::XrTracker;
pub struct XrCameraPlugin;
impl Plugin for XrCameraPlugin {
fn build(&self, app: &mut App) {
app.add_plugins(CameraProjectionPlugin::<XrProjection>::default());
app.add_systems(
PostUpdate,
update_frusta::<XrProjection>
.after(TransformSystem::TransformPropagate)
.before(VisibilitySystems::UpdateFrusta),
);
if app.is_plugin_added::<PbrPlugin>() {
app.add_plugins(PbrProjectionPlugin::<XrProjection>::default());
}
app.add_plugins((
ExtractComponentPlugin::<XrProjection>::default(),
ExtractComponentPlugin::<XrCamera>::default(),
));
}
}
#[derive(Debug, Clone, Reflect, ExtractComponent)]
#[reflect(Component, Default)]
pub struct XrProjection {
pub projection_matrix: Mat4,
pub near: f32,
}
impl Component for XrProjection {
const STORAGE_TYPE: StorageType = StorageType::Table;
fn register_component_hooks(hooks: &mut bevy::ecs::component::ComponentHooks) {
hooks.on_add(|mut world, entity, _| {
world.commands().entity(entity).remove::<Projection>();
});
}
}
impl Default for XrProjection {
fn default() -> Self {
Self {
near: 0.1,
projection_matrix: Mat4::IDENTITY,
}
}
}
/// Marker component for an XR view. It is the backends responsibility to update this.
#[derive(Clone, Copy, Component, ExtractComponent, Debug, Default)]
#[require(Camera3d, XrProjection, XrTracker)]
pub struct XrCamera(pub u32);
impl CameraProjection for XrProjection {
fn update(&mut self, _width: f32, _height: f32) {}
fn far(&self) -> f32 {
self.projection_matrix.to_cols_array()[14]
/ (self.projection_matrix.to_cols_array()[10] + 1.0)
}
// TODO calculate this properly
fn get_frustum_corners(&self, _z_near: f32, _z_far: f32) -> [Vec3A; 8] {
let ndc_corners = [
Vec3A::new(1.0, -1.0, 1.0), // Bottom-right far
Vec3A::new(1.0, 1.0, 1.0), // Top-right far
Vec3A::new(-1.0, 1.0, 1.0), // Top-left far
Vec3A::new(-1.0, -1.0, 1.0), // Bottom-left far
Vec3A::new(1.0, -1.0, -1.0), // Bottom-right near
Vec3A::new(1.0, 1.0, -1.0), // Top-right near
Vec3A::new(-1.0, 1.0, -1.0), // Top-left near
Vec3A::new(-1.0, -1.0, -1.0), // Bottom-left near
];
let mut view_space_corners = [Vec3A::ZERO; 8];
let inverse_matrix = self.projection_matrix.inverse();
for (i, corner) in ndc_corners.into_iter().enumerate() {
view_space_corners[i] = inverse_matrix.transform_point3a(corner);
}
view_space_corners
}
fn get_clip_from_view(&self) -> Mat4 {
self.projection_matrix
}
fn get_clip_from_view_for_sub(&self, _sub_view: &bevy::render::camera::SubCameraView) -> Mat4 {
panic!("sub view not supported for xr camera");
}
}