-
Notifications
You must be signed in to change notification settings - Fork 23
/
session.rs
289 lines (256 loc) · 8.33 KB
/
session.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use crate::Device;
use crate::Error;
use crate::Event;
use crate::Floor;
use crate::Frame;
use crate::InputSource;
use crate::Native;
use crate::Receiver;
use crate::Sender;
use crate::Viewport;
use crate::Views;
use crate::WebGLContextId;
use crate::WebGLExternalImageApi;
use crate::WebGLTextureId;
use euclid::default::Size2D as UntypedSize2D;
use euclid::RigidTransform3D;
use euclid::Size2D;
use gleam::gl::GLsizei;
use std::thread;
use std::time::Duration;
#[cfg(feature = "ipc")]
use serde::{Deserialize, Serialize};
// How long to wait for an rAF.
static TIMEOUT: Duration = Duration::from_millis(5);
/// https://www.w3.org/TR/webxr/#xrsessionmode-enum
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
#[cfg_attr(feature = "ipc", derive(Serialize, Deserialize))]
pub enum SessionMode {
Inline,
ImmersiveVR,
ImmersiveAR,
}
/// https://www.w3.org/TR/hr-time/#dom-domhighrestimestamp
pub type HighResTimeStamp = f64;
// The messages that are sent from the content thread to the session thread.
#[cfg_attr(feature = "ipc", derive(Serialize, Deserialize))]
enum SessionMsg {
SetTexture(WebGLContextId, WebGLTextureId, UntypedSize2D<GLsizei>),
SetEventDest(Sender<Event>),
RequestAnimationFrame(Sender<(HighResTimeStamp, Frame)>),
RenderAnimationFrame,
Quit,
}
#[cfg_attr(feature = "ipc", derive(Serialize, Deserialize))]
#[derive(Clone)]
pub struct Quitter {
sender: Sender<SessionMsg>,
}
impl Quitter {
pub fn quit(&self) {
let _ = self.sender.send(SessionMsg::Quit);
}
}
/// An object that represents an XR session.
/// This is owned by the content thread.
/// https://www.w3.org/TR/webxr/#xrsession-interface
#[cfg_attr(feature = "ipc", derive(Serialize, Deserialize))]
pub struct Session {
floor_transform: RigidTransform3D<f32, Native, Floor>,
views: Views,
resolution: Size2D<i32, Viewport>,
sender: Sender<SessionMsg>,
initial_inputs: Vec<InputSource>,
}
impl Session {
pub fn floor_transform(&self) -> RigidTransform3D<f32, Native, Floor> {
self.floor_transform.clone()
}
pub fn initial_inputs(&self) -> &[InputSource] {
&self.initial_inputs
}
pub fn views(&self) -> Views {
self.views.clone()
}
pub fn recommended_framebuffer_resolution(&self) -> Size2D<i32, Viewport> {
self.resolution
}
pub fn set_texture(
&mut self,
ctxt: WebGLContextId,
txt: WebGLTextureId,
size: UntypedSize2D<GLsizei>,
) {
let _ = self.sender.send(SessionMsg::SetTexture(ctxt, txt, size));
}
pub fn request_animation_frame(&mut self, dest: Sender<(HighResTimeStamp, Frame)>) {
let _ = self.sender.send(SessionMsg::RequestAnimationFrame(dest));
}
pub fn set_event_dest(&mut self, dest: Sender<Event>) {
let _ = self.sender.send(SessionMsg::SetEventDest(dest));
}
pub fn render_animation_frame(&mut self) {
let _ = self.sender.send(SessionMsg::RenderAnimationFrame);
}
pub fn end_session(&mut self) {
let _ = self.sender.send(SessionMsg::Quit);
}
}
/// For devices that want to do their own thread management, the `SessionThread` type is exposed.
pub struct SessionThread<D> {
receiver: Receiver<SessionMsg>,
sender: Sender<SessionMsg>,
webgl: Box<dyn WebGLExternalImageApi>,
texture: Option<(WebGLContextId, WebGLTextureId, UntypedSize2D<GLsizei>)>,
timestamp: HighResTimeStamp,
running: bool,
device: D,
}
impl<D: Device> SessionThread<D> {
pub fn new(
mut device: D,
webgl: Box<dyn WebGLExternalImageApi>,
) -> Result<SessionThread<D>, Error> {
let (sender, receiver) = crate::channel().or(Err(Error::CommunicationError))?;
device.set_quitter(Quitter {
sender: sender.clone(),
});
let timestamp = 0.0;
let texture = None;
let running = true;
Ok(SessionThread {
sender,
receiver,
device,
webgl,
texture,
timestamp,
running,
})
}
pub fn new_session(&mut self) -> Session {
let floor_transform = self.device.floor_transform();
let views = self.device.views();
let resolution = self.device.recommended_framebuffer_resolution();
let sender = self.sender.clone();
let initial_inputs = self.device.initial_inputs();
Session {
floor_transform,
views,
resolution,
sender,
initial_inputs,
}
}
pub fn run(&mut self) {
loop {
if let Ok(msg) = self.receiver.recv() {
if !self.handle_msg(msg) {
self.running = false;
break;
}
} else {
break;
}
}
}
fn handle_msg(&mut self, msg: SessionMsg) -> bool {
match msg {
SessionMsg::SetTexture(ctxt, txt, size) => {
self.texture = Some((ctxt, txt, size));
}
SessionMsg::SetEventDest(dest) => {
self.device.set_event_dest(dest);
}
SessionMsg::RequestAnimationFrame(dest) => {
let timestamp = self.timestamp;
let frame = self.device.wait_for_animation_frame();
let _ = dest.send((timestamp, frame));
}
SessionMsg::RenderAnimationFrame => {
self.timestamp += 1.0;
if let Some((ctxt, txt, size)) = self.texture {
let sync = self.webgl.lock(ctxt);
self.device.render_animation_frame(txt, size, sync);
self.webgl.unlock(ctxt);
}
}
SessionMsg::Quit => {
self.device.quit();
return false;
}
}
true
}
}
/// Devices that need to can run sessions on the main thread.
pub trait MainThreadSession: 'static {
fn run_one_frame(&mut self);
fn running(&self) -> bool;
}
impl<D: Device> MainThreadSession for SessionThread<D> {
fn run_one_frame(&mut self) {
let timestamp = self.timestamp;
while timestamp == self.timestamp && self.running {
if let Ok(msg) = crate::recv_timeout(&self.receiver, TIMEOUT) {
self.handle_msg(msg);
} else {
break;
}
}
}
fn running(&self) -> bool {
self.running
}
}
/// A type for building XR sessions
pub struct SessionBuilder<'a> {
webgl: &'a dyn WebGLExternalImageApi,
sessions: &'a mut Vec<Box<dyn MainThreadSession>>,
}
impl<'a> SessionBuilder<'a> {
pub(crate) fn new(
webgl: &'a dyn WebGLExternalImageApi,
sessions: &'a mut Vec<Box<dyn MainThreadSession>>,
) -> SessionBuilder<'a> {
SessionBuilder { webgl, sessions }
}
/// For devices which are happy to hand over thread management to webxr.
pub fn spawn<D, F>(self, factory: F) -> Result<Session, Error>
where
F: 'static + FnOnce() -> Result<D, Error> + Send,
D: Device,
{
let (acks, ackr) = crate::channel().or(Err(Error::CommunicationError))?;
let webgl = self.webgl.clone_box();
thread::spawn(move || {
match factory().and_then(|device| SessionThread::new(device, webgl)) {
Ok(mut thread) => {
let session = thread.new_session();
let _ = acks.send(Ok(session));
thread.run();
}
Err(err) => {
let _ = acks.send(Err(err));
}
}
});
ackr.recv().unwrap_or(Err(Error::CommunicationError))
}
/// For devices that need to run on the main thread.
pub fn run_on_main_thread<D, F>(self, factory: F) -> Result<Session, Error>
where
F: 'static + FnOnce() -> Result<D, Error>,
D: Device,
{
let device = factory()?;
let webgl = self.webgl.clone_box();
let mut session_thread = SessionThread::new(device, webgl)?;
let session = session_thread.new_session();
self.sessions.push(Box::new(session_thread));
Ok(session)
}
}