Expose predict_motion from server_core

alvr-org · Dec 15, 2024 · b9b678f · b9b678f
1 parent 37693c3
commit b9b678f
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Showing 2 changed files with 28 additions and 20 deletions.
diff --git a/alvr/server_core/src/lib.rs b/alvr/server_core/src/lib.rs
@@ -12,7 +12,7 @@ mod web_server;
 
 pub use c_api::*;
 pub use logging_backend::init_logging;
-pub use tracking::HandType;
+pub use tracking::{predict_motion, HandType};
 
 use crate::connection::VideoPacket;
 use alvr_common::{

diff --git a/alvr/server_core/src/tracking/mod.rs b/alvr/server_core/src/tracking/mod.rs
@@ -42,6 +42,32 @@ pub enum HandType {
     Right = 1,
 }
 
+pub fn predict_motion(
+    motion: DeviceMotion,
+    sample_timestamp: Duration,
+    target_timestamp: Duration,
+) -> DeviceMotion {
+    // There is no simple sub for Duration, this is needed to get signed difference
+    let delta_time_s = target_timestamp
+        .saturating_sub(sample_timestamp)
+        .as_secs_f32()
+        - sample_timestamp
+            .saturating_sub(target_timestamp)
+            .as_secs_f32();
+
+    let delta_position = motion.linear_velocity * delta_time_s;
+    let delta_orientation = Quat::from_scaled_axis(motion.angular_velocity * delta_time_s);
+
+    DeviceMotion {
+        pose: Pose {
+            orientation: delta_orientation * motion.pose.orientation,
+            position: motion.pose.position + delta_position,
+        },
+        linear_velocity: motion.linear_velocity,
+        angular_velocity: motion.angular_velocity,
+    }
+}
+
 // todo: Move this struct to Settings and use it for every tracked device
 #[derive(Default)]
 struct MotionConfig {
@@ -259,25 +285,7 @@ impl TrackingManager {
     ) -> Option<DeviceMotion> {
         let motion = self.get_device_motion(device_id, sample_timestamp)?;
 
-        // There is no simple sub for Duration, this is needed to get signed difference
-        let delta_time_s = target_timestamp
-            .saturating_sub(sample_timestamp)
-            .as_secs_f32()
-            - sample_timestamp
-                .saturating_sub(target_timestamp)
-                .as_secs_f32();
-
-        let delta_position = motion.linear_velocity * delta_time_s;
-        let delta_orientation = Quat::from_scaled_axis(motion.angular_velocity * delta_time_s);
-
-        Some(DeviceMotion {
-            pose: Pose {
-                orientation: delta_orientation * motion.pose.orientation,
-                position: motion.pose.position + delta_position,
-            },
-            linear_velocity: motion.linear_velocity,
-            angular_velocity: motion.angular_velocity,
-        })
+        Some(predict_motion(motion, sample_timestamp, target_timestamp))
     }
 
     pub fn report_hand_skeleton(