forked from bevyengine/bevy
-
Notifications
You must be signed in to change notification settings - Fork 1
/
lib.rs
302 lines (274 loc) · 10.5 KB
/
lib.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
290
291
292
293
294
295
296
297
298
299
300
301
302
//! Animation for the game engine Bevy
#![warn(missing_docs)]
use std::ops::Deref;
use bevy_app::{App, CoreStage, Plugin};
use bevy_asset::{AddAsset, Assets, Handle};
use bevy_core::Name;
use bevy_ecs::{
change_detection::DetectChanges,
entity::Entity,
prelude::Component,
reflect::ReflectComponent,
schedule::IntoSystemDescriptor,
system::{Query, Res},
};
use bevy_hierarchy::Children;
use bevy_math::{Quat, Vec3};
use bevy_reflect::{Reflect, TypeUuid};
use bevy_time::Time;
use bevy_transform::{prelude::Transform, TransformSystem};
use bevy_utils::{tracing::warn, HashMap};
#[allow(missing_docs)]
pub mod prelude {
#[doc(hidden)]
pub use crate::{
AnimationClip, AnimationPlayer, AnimationPlugin, EntityPath, Keyframes, VariableCurve,
};
}
/// List of keyframes for one of the attribute of a [`Transform`].
#[derive(Clone, Debug)]
pub enum Keyframes {
/// Keyframes for rotation.
Rotation(Vec<Quat>),
/// Keyframes for translation.
Translation(Vec<Vec3>),
/// Keyframes for scale.
Scale(Vec<Vec3>),
}
/// Describes how an attribute of a [`Transform`] should be animated.
///
/// `keyframe_timestamps` and `keyframes` should have the same length.
#[derive(Clone, Debug)]
pub struct VariableCurve {
/// Timestamp for each of the keyframes.
pub keyframe_timestamps: Vec<f32>,
/// List of the keyframes.
pub keyframes: Keyframes,
}
/// Path to an entity, with [`Name`]s. Each entity in a path must have a name.
#[derive(Clone, Debug, Hash, PartialEq, Eq, Default)]
pub struct EntityPath {
/// Parts of the path
pub parts: Vec<Name>,
}
/// A list of [`VariableCurve`], and the [`EntityPath`] to which they apply.
#[derive(Clone, TypeUuid, Debug, Default)]
#[uuid = "d81b7179-0448-4eb0-89fe-c067222725bf"]
pub struct AnimationClip {
curves: HashMap<EntityPath, Vec<VariableCurve>>,
duration: f32,
}
impl AnimationClip {
#[inline]
/// Hashmap of the [`VariableCurve`]s per [`EntityPath`].
pub fn curves(&self) -> &HashMap<EntityPath, Vec<VariableCurve>> {
&self.curves
}
/// Duration of the clip, represented in seconds
#[inline]
pub fn duration(&self) -> f32 {
self.duration
}
/// Add a [`VariableCurve`] to an [`EntityPath`].
pub fn add_curve_to_path(&mut self, path: EntityPath, curve: VariableCurve) {
// Update the duration of the animation by this curve duration if it's longer
self.duration = self
.duration
.max(*curve.keyframe_timestamps.last().unwrap_or(&0.0));
self.curves.entry(path).or_default().push(curve);
}
}
/// Animation controls
#[derive(Component, Reflect)]
#[reflect(Component)]
pub struct AnimationPlayer {
paused: bool,
repeat: bool,
speed: f32,
elapsed: f32,
animation_clip: Handle<AnimationClip>,
}
impl Default for AnimationPlayer {
fn default() -> Self {
Self {
paused: false,
repeat: false,
speed: 1.0,
elapsed: 0.0,
animation_clip: Default::default(),
}
}
}
impl AnimationPlayer {
/// Start playing an animation, resetting state of the player
pub fn play(&mut self, handle: Handle<AnimationClip>) -> &mut Self {
*self = Self {
animation_clip: handle,
..Default::default()
};
self
}
/// Set the animation to repeat
pub fn repeat(&mut self) -> &mut Self {
self.repeat = true;
self
}
/// Stop the animation from repeating
pub fn stop_repeating(&mut self) -> &mut Self {
self.repeat = false;
self
}
/// Pause the animation
pub fn pause(&mut self) {
self.paused = true;
}
/// Unpause the animation
pub fn resume(&mut self) {
self.paused = false;
}
/// Is the animation paused
pub fn is_paused(&self) -> bool {
self.paused
}
/// Speed of the animation playback
pub fn speed(&self) -> f32 {
self.speed
}
/// Set the speed of the animation playback
pub fn set_speed(&mut self, speed: f32) -> &mut Self {
self.speed = speed;
self
}
/// Time elapsed playing the animation
pub fn elapsed(&self) -> f32 {
self.elapsed
}
/// Seek to a specific time in the animation
pub fn set_elapsed(&mut self, elapsed: f32) -> &mut Self {
self.elapsed = elapsed;
self
}
}
/// System that will play all animations, using any entity with a [`AnimationPlayer`]
/// and a [`Handle<AnimationClip>`] as an animation root
pub fn animation_player(
time: Res<Time>,
animations: Res<Assets<AnimationClip>>,
mut animation_players: Query<(Entity, &mut AnimationPlayer)>,
names: Query<&Name>,
mut transforms: Query<&mut Transform>,
children: Query<&Children>,
) {
for (entity, mut player) in &mut animation_players {
if let Some(animation_clip) = animations.get(&player.animation_clip) {
// Continue if paused unless the `AnimationPlayer` was changed
// This allow the animation to still be updated if the player.elapsed field was manually updated in pause
if player.paused && !player.is_changed() {
continue;
}
if !player.paused {
player.elapsed += time.delta_seconds() * player.speed;
}
let mut elapsed = player.elapsed;
if player.repeat {
elapsed %= animation_clip.duration;
}
if elapsed < 0.0 {
elapsed += animation_clip.duration;
}
'entity: for (path, curves) in &animation_clip.curves {
// PERF: finding the target entity can be optimised
let mut current_entity = entity;
// Ignore the first name, it is the root node which we already have
for part in path.parts.iter().skip(1) {
let mut found = false;
if let Ok(children) = children.get(current_entity) {
for child in children.deref() {
if let Ok(name) = names.get(*child) {
if name == part {
// Found a children with the right name, continue to the next part
current_entity = *child;
found = true;
break;
}
}
}
}
if !found {
warn!("Entity not found for path {:?} on part {:?}", path, part);
continue 'entity;
}
}
if let Ok(mut transform) = transforms.get_mut(current_entity) {
for curve in curves {
// Some curves have only one keyframe used to set a transform
if curve.keyframe_timestamps.len() == 1 {
match &curve.keyframes {
Keyframes::Rotation(keyframes) => transform.rotation = keyframes[0],
Keyframes::Translation(keyframes) => {
transform.translation = keyframes[0];
}
Keyframes::Scale(keyframes) => transform.scale = keyframes[0],
}
continue;
}
// Find the current keyframe
// PERF: finding the current keyframe can be optimised
let step_start = match curve
.keyframe_timestamps
.binary_search_by(|probe| probe.partial_cmp(&elapsed).unwrap())
{
Ok(n) if n >= curve.keyframe_timestamps.len() - 1 => continue, // this curve is finished
Ok(i) => i,
Err(0) => continue, // this curve isn't started yet
Err(n) if n > curve.keyframe_timestamps.len() - 1 => continue, // this curve is finished
Err(i) => i - 1,
};
let ts_start = curve.keyframe_timestamps[step_start];
let ts_end = curve.keyframe_timestamps[step_start + 1];
let lerp = (elapsed - ts_start) / (ts_end - ts_start);
// Apply the keyframe
match &curve.keyframes {
Keyframes::Rotation(keyframes) => {
let rot_start = keyframes[step_start];
let mut rot_end = keyframes[step_start + 1];
// Choose the smallest angle for the rotation
if rot_end.dot(rot_start) < 0.0 {
rot_end = -rot_end;
}
// Rotations are using a spherical linear interpolation
transform.rotation =
rot_start.normalize().slerp(rot_end.normalize(), lerp);
}
Keyframes::Translation(keyframes) => {
let translation_start = keyframes[step_start];
let translation_end = keyframes[step_start + 1];
let result = translation_start.lerp(translation_end, lerp);
transform.translation = result;
}
Keyframes::Scale(keyframes) => {
let scale_start = keyframes[step_start];
let scale_end = keyframes[step_start + 1];
let result = scale_start.lerp(scale_end, lerp);
transform.scale = result;
}
}
}
}
}
}
}
}
/// Adds animation support to an app
#[derive(Default)]
pub struct AnimationPlugin {}
impl Plugin for AnimationPlugin {
fn build(&self, app: &mut App) {
app.add_asset::<AnimationClip>()
.register_type::<AnimationPlayer>()
.add_system_to_stage(
CoreStage::PostUpdate,
animation_player.before(TransformSystem::TransformPropagate),
);
}
}