Add a standalone look_at function

matthiascy · Jun 1, 2022 · 0276fb4 · 0276fb4
1 parent baea884
commit 0276fb4
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Showing 3 changed files with 22 additions and 17 deletions.
diff --git a/src/drivers/look_at.rs b/src/drivers/look_at.rs
@@ -1,13 +1,13 @@
 use std::marker::PhantomData;
 
-use glam::{Mat3, Quat, Vec3};
+use glam::Vec3;
 
 use crate::{
     driver::RigDriver,
     handedness::Handedness,
     rig::RigUpdateParams,
     transform::Transform,
-    util::{ExpSmoothed, ExpSmoothingParams},
+    util::{look_at, ExpSmoothed, ExpSmoothingParams},
 };
 
 /// Rotates the camera to point at a world-space position.
@@ -66,18 +66,7 @@ impl<H: Handedness> RigDriver<H> for LookAt {
             },
         );
 
-        let rotation = (target - params.parent.position)
-            .try_normalize()
-            .and_then(|forward| {
-                let right = H::right_from_up_and_forward(Vec3::Y, forward).try_normalize()?;
-                let up = H::up_from_right_and_forward(right, forward);
-                Some(Quat::from_mat3(&Mat3::from_cols(
-                    right,
-                    up,
-                    forward * H::FORWARD_Z_SIGN,
-                )))
-            })
-            .unwrap_or_default();
+        let rotation = look_at::<H>(target - params.parent.position);
 
         Transform {
             position: params.parent.position,

diff --git a/src/lib.rs b/src/lib.rs
@@ -37,7 +37,6 @@ pub mod handedness;
 pub mod prelude;
 pub mod rig;
 pub mod transform;
-
-mod util;
+pub mod util;
 
 pub use glam;
diff --git a/src/util.rs b/src/util.rs
@@ -1,4 +1,6 @@
-use glam::{Quat, Vec3};
+use glam::{Mat3, Quat, Vec3};
+
+use crate::prelude::Handedness;
 
 pub(crate) trait Interpolate {
     fn interpolate(self, other: Self, t: f32) -> Self;
@@ -51,3 +53,18 @@ impl<T: Interpolate + Copy + std::fmt::Debug> ExpSmoothed<T> {
         }
     }
 }
+
+pub fn look_at<H: Handedness>(forward: Vec3) -> Quat {
+    forward
+        .try_normalize()
+        .and_then(|forward| {
+            let right = H::right_from_up_and_forward(Vec3::Y, forward).try_normalize()?;
+            let up = H::up_from_right_and_forward(right, forward);
+            Some(Quat::from_mat3(&Mat3::from_cols(
+                right,
+                up,
+                forward * H::FORWARD_Z_SIGN,
+            )))
+        })
+        .unwrap_or_default()
+}