Files
bevy_oxr/crates/bevy_openxr/src/render.rs
2024-04-13 17:05:47 -05:00

376 lines
13 KiB
Rust

use bevy::{
prelude::*,
render::{
camera::{ManualTextureView, ManualTextureViewHandle, ManualTextureViews, RenderTarget},
extract_resource::ExtractResourcePlugin,
renderer::render_system,
view::ExtractedView,
Render, RenderApp, RenderSet,
},
transform::TransformSystem,
};
use bevy_xr::camera::{XrCamera, XrCameraBundle, XrProjection};
use openxr::{CompositionLayerFlags, ViewStateFlags};
use crate::init::{session_started, XrPreUpdateSet};
use crate::layer_builder::*;
use crate::resources::*;
pub struct XrRenderPlugin;
impl Plugin for XrRenderPlugin {
fn build(&self, app: &mut App) {
app.add_plugins((ExtractResourcePlugin::<XrViews>::default(),))
.add_systems(
PreUpdate,
(
init_views.run_if(resource_added::<XrGraphicsInfo>),
wait_frame.run_if(session_started),
locate_views.run_if(session_started),
update_views.run_if(session_started),
)
.chain()
.after(XrPreUpdateSet::HandleEvents),
)
.add_systems(
PostUpdate,
(locate_views, update_views)
.chain()
.run_if(session_started)
.before(TransformSystem::TransformPropagate),
);
app.sub_app_mut(RenderApp).add_systems(
Render,
(
(
insert_texture_views,
locate_views,
update_views_render_world,
)
.chain()
.in_set(RenderSet::PrepareAssets),
begin_frame
.before(RenderSet::Queue)
.before(insert_texture_views),
wait_image.in_set(RenderSet::Render).before(render_system),
(end_frame).chain().in_set(RenderSet::Cleanup),
)
.run_if(session_started),
);
}
}
pub const XR_TEXTURE_INDEX: u32 = 3383858418;
// TODO: have cameras initialized externally and then recieved by this function.
/// This is needed to properly initialize the texture views so that bevy will set them to the correct resolution despite them being updated in the render world.
pub fn init_views(
graphics_info: Res<XrGraphicsInfo>,
mut manual_texture_views: ResMut<ManualTextureViews>,
swapchain_images: Res<XrSwapchainImages>,
mut commands: Commands,
) {
let _span = info_span!("xr_init_views");
let temp_tex = swapchain_images.first().unwrap();
// this for loop is to easily add support for quad or mono views in the future.
let mut views = vec![];
for index in 0..2 {
info!("{}", graphics_info.resolution);
let view_handle =
add_texture_view(&mut manual_texture_views, temp_tex, &graphics_info, index);
commands.spawn((
XrCameraBundle {
camera: Camera {
target: RenderTarget::TextureView(view_handle),
..Default::default()
},
view: XrCamera(index),
..Default::default()
},
// OpenXrTracker,
// XrRoot::default(),
));
views.push(default());
}
commands.insert_resource(XrViews(views));
}
pub fn wait_frame(mut frame_waiter: ResMut<XrFrameWaiter>, mut commands: Commands) {
let _span = info_span!("xr_wait_frame");
let state = frame_waiter.wait().expect("Failed to wait frame");
// Here we insert the predicted display time for when this frame will be displayed.
// TODO: don't add predicted_display_period if pipelined rendering plugin not enabled
commands.insert_resource(XrTime(state.predicted_display_time));
}
pub fn locate_views(
session: Res<XrSession>,
stage: Res<XrStage>,
time: Res<XrTime>,
mut openxr_views: ResMut<XrViews>,
) {
let _span = info_span!("xr_locate_views");
let (flags, xr_views) = session
.locate_views(
openxr::ViewConfigurationType::PRIMARY_STEREO,
**time,
&stage,
)
.expect("Failed to locate views");
if openxr_views.len() != xr_views.len() {
openxr_views.resize(xr_views.len(), default());
}
match (
flags & ViewStateFlags::ORIENTATION_VALID == ViewStateFlags::ORIENTATION_VALID,
flags & ViewStateFlags::POSITION_VALID == ViewStateFlags::POSITION_VALID,
) {
(true, true) => *openxr_views = XrViews(xr_views),
(true, false) => {
for (i, view) in openxr_views.iter_mut().enumerate() {
view.pose.orientation = xr_views[i].pose.orientation;
}
}
(false, true) => {
for (i, view) in openxr_views.iter_mut().enumerate() {
view.pose.position = xr_views[i].pose.position;
}
}
(false, false) => {}
}
}
pub fn update_views(
mut query: Query<(&mut Transform, &mut XrProjection, &XrCamera)>,
views: ResMut<XrViews>,
) {
for (mut transform, mut projection, camera) in query.iter_mut() {
let Some(view) = views.get(camera.0 as usize) else {
continue;
};
let projection_matrix = calculate_projection(projection.near, view.fov);
projection.projection_matrix = projection_matrix;
let openxr::Quaternionf { x, y, z, w } = view.pose.orientation;
let rotation = Quat::from_xyzw(x, y, z, w);
transform.rotation = rotation;
let openxr::Vector3f { x, y, z } = view.pose.position;
let translation = Vec3::new(x, y, z);
transform.translation = translation;
}
}
pub fn update_views_render_world(
views: Res<XrViews>,
root: Res<XrRootTransform>,
mut query: Query<(&mut ExtractedView, &XrCamera)>,
) {
for (mut extracted_view, camera) in query.iter_mut() {
let Some(view) = views.get(camera.0 as usize) else {
continue;
};
let mut transform = Transform::IDENTITY;
let openxr::Quaternionf { x, y, z, w } = view.pose.orientation;
let rotation = Quat::from_xyzw(x, y, z, w);
transform.rotation = rotation;
let openxr::Vector3f { x, y, z } = view.pose.position;
let translation = Vec3::new(x, y, z);
transform.translation = translation;
extracted_view.transform = root.0.mul_transform(transform);
}
}
fn calculate_projection(near_z: f32, fov: openxr::Fovf) -> Mat4 {
// symmetric perspective for debugging
// let x_fov = (self.fov.angle_left.abs() + self.fov.angle_right.abs());
// let y_fov = (self.fov.angle_up.abs() + self.fov.angle_down.abs());
// return Mat4::perspective_infinite_reverse_rh(y_fov, x_fov / y_fov, self.near);
let is_vulkan_api = false; // FIXME wgpu probably abstracts this
let far_z = -1.; // use infinite proj
// let far_z = self.far;
let tan_angle_left = fov.angle_left.tan();
let tan_angle_right = fov.angle_right.tan();
let tan_angle_down = fov.angle_down.tan();
let tan_angle_up = fov.angle_up.tan();
let tan_angle_width = tan_angle_right - tan_angle_left;
// Set to tanAngleDown - tanAngleUp for a clip space with positive Y
// down (Vulkan). Set to tanAngleUp - tanAngleDown for a clip space with
// positive Y up (OpenGL / D3D / Metal).
// const float tanAngleHeight =
// graphicsApi == GRAPHICS_VULKAN ? (tanAngleDown - tanAngleUp) : (tanAngleUp - tanAngleDown);
let tan_angle_height = if is_vulkan_api {
tan_angle_down - tan_angle_up
} else {
tan_angle_up - tan_angle_down
};
// Set to nearZ for a [-1,1] Z clip space (OpenGL / OpenGL ES).
// Set to zero for a [0,1] Z clip space (Vulkan / D3D / Metal).
// const float offsetZ =
// (graphicsApi == GRAPHICS_OPENGL || graphicsApi == GRAPHICS_OPENGL_ES) ? nearZ : 0;
// FIXME handle enum of graphics apis
let offset_z = 0.;
let mut cols: [f32; 16] = [0.0; 16];
if far_z <= near_z {
// place the far plane at infinity
cols[0] = 2. / tan_angle_width;
cols[4] = 0.;
cols[8] = (tan_angle_right + tan_angle_left) / tan_angle_width;
cols[12] = 0.;
cols[1] = 0.;
cols[5] = 2. / tan_angle_height;
cols[9] = (tan_angle_up + tan_angle_down) / tan_angle_height;
cols[13] = 0.;
cols[2] = 0.;
cols[6] = 0.;
cols[10] = -1.;
cols[14] = -(near_z + offset_z);
cols[3] = 0.;
cols[7] = 0.;
cols[11] = -1.;
cols[15] = 0.;
// bevy uses the _reverse_ infinite projection
// https://dev.theomader.com/depth-precision/
let z_reversal = Mat4::from_cols_array_2d(&[
[1f32, 0., 0., 0.],
[0., 1., 0., 0.],
[0., 0., -1., 0.],
[0., 0., 1., 1.],
]);
return z_reversal * Mat4::from_cols_array(&cols);
} else {
// normal projection
cols[0] = 2. / tan_angle_width;
cols[4] = 0.;
cols[8] = (tan_angle_right + tan_angle_left) / tan_angle_width;
cols[12] = 0.;
cols[1] = 0.;
cols[5] = 2. / tan_angle_height;
cols[9] = (tan_angle_up + tan_angle_down) / tan_angle_height;
cols[13] = 0.;
cols[2] = 0.;
cols[6] = 0.;
cols[10] = -(far_z + offset_z) / (far_z - near_z);
cols[14] = -(far_z * (near_z + offset_z)) / (far_z - near_z);
cols[3] = 0.;
cols[7] = 0.;
cols[11] = -1.;
cols[15] = 0.;
}
Mat4::from_cols_array(&cols)
}
/// # Safety
/// Images inserted into texture views here should not be written to until [`wait_image`] is ran
pub fn insert_texture_views(
swapchain_images: Res<XrSwapchainImages>,
mut swapchain: ResMut<XrSwapchain>,
mut manual_texture_views: ResMut<ManualTextureViews>,
graphics_info: Res<XrGraphicsInfo>,
) {
let _span = info_span!("xr_insert_texture_views");
let index = swapchain.acquire_image().expect("Failed to acquire image");
let image = &swapchain_images[index as usize];
for i in 0..2 {
add_texture_view(&mut manual_texture_views, image, &graphics_info, i);
}
}
pub fn wait_image(mut swapchain: ResMut<XrSwapchain>) {
swapchain
.wait_image(openxr::Duration::INFINITE)
.expect("Failed to wait image");
}
pub fn add_texture_view(
manual_texture_views: &mut ManualTextureViews,
texture: &wgpu::Texture,
info: &XrGraphicsInfo,
index: u32,
) -> ManualTextureViewHandle {
let view = texture.create_view(&wgpu::TextureViewDescriptor {
dimension: Some(wgpu::TextureViewDimension::D2),
array_layer_count: Some(1),
base_array_layer: index,
..default()
});
let view = ManualTextureView {
texture_view: view.into(),
size: info.resolution,
format: info.format,
};
let handle = ManualTextureViewHandle(XR_TEXTURE_INDEX + index);
manual_texture_views.insert(handle, view);
handle
}
pub fn begin_frame(mut frame_stream: ResMut<XrFrameStream>) {
frame_stream.begin().expect("Failed to begin frame")
}
pub fn end_frame(
mut frame_stream: ResMut<XrFrameStream>,
mut swapchain: ResMut<XrSwapchain>,
stage: Res<XrStage>,
display_time: Res<XrTime>,
graphics_info: Res<XrGraphicsInfo>,
openxr_views: Res<XrViews>,
) {
let _span = info_span!("xr_end_frame");
swapchain.release_image().unwrap();
let rect = openxr::Rect2Di {
offset: openxr::Offset2Di { x: 0, y: 0 },
extent: openxr::Extent2Di {
width: graphics_info.resolution.x as _,
height: graphics_info.resolution.y as _,
},
};
frame_stream
.end(
**display_time,
graphics_info.blend_mode,
&[&CompositionLayerProjection::new()
.layer_flags(CompositionLayerFlags::BLEND_TEXTURE_SOURCE_ALPHA)
.space(&stage)
.views(&[
CompositionLayerProjectionView::new()
.pose(openxr_views.0[0].pose)
.fov(openxr_views.0[0].fov)
.sub_image(
SwapchainSubImage::new()
.swapchain(&swapchain)
.image_array_index(0)
.image_rect(rect),
),
CompositionLayerProjectionView::new()
.pose(openxr_views.0[1].pose)
.fov(openxr_views.0[1].fov)
.sub_image(
SwapchainSubImage::new()
.swapchain(&swapchain)
.image_array_index(1)
.image_rect(rect),
),
])],
)
.expect("Failed to end frame");
}