blender_armature/action/bone_keyframes/
sample.rs

1use crate::action::get_surrounding_keyframes;
2use crate::{interpolate_bone, Bone, BoneKeyframes, SampleDesc};
3
4impl BoneKeyframes {
5    /// Sample the bone transforms
6    pub fn sample(&self, joint_idx: u8, sample_desc: SampleDesc) -> Bone {
7        let keyframes = self.keyframes.get(&joint_idx).unwrap();
8
9        let (lowest_keyframe, highest_keyframe) = self.frame_range_inclusive().unwrap();
10
11        let mut frames_elapsed = sample_desc.frame_offset.get();
12
13        let mut key_time_to_sample = lowest_keyframe as f32 + frames_elapsed;
14
15        let action_duration = (highest_keyframe - lowest_keyframe) as f32;
16
17        if frames_elapsed > action_duration {
18            if sample_desc.should_loop {
19                frames_elapsed = frames_elapsed % action_duration;
20            } else {
21                frames_elapsed = action_duration;
22            }
23
24            key_time_to_sample = lowest_keyframe as f32 + frames_elapsed;
25        }
26
27        let (action_lower_keyframe, action_upper_keyframe) =
28            get_surrounding_keyframes(keyframes, key_time_to_sample);
29
30        let percent_elapsed_into_keyframe = if action_lower_keyframe == action_upper_keyframe {
31            0.0
32        } else {
33            (key_time_to_sample - action_lower_keyframe.frame() as f32)
34                / (action_upper_keyframe.frame() - action_lower_keyframe.frame()) as f32
35        };
36
37        let lower_bone = action_lower_keyframe.bone();
38        let upper_bone = action_upper_keyframe.bone();
39
40        interpolate_bone(lower_bone, upper_bone, percent_elapsed_into_keyframe)
41    }
42}