chore: added given sample code.

src/toolbox.rs

@@ -0,0 +1,36 @@
+extern crate nalgebra_glm as glm;
+use std::f64::consts::PI;
+
+pub struct Heading {
+    pub x     : f32,
+    pub z     : f32,
+    pub roll  : f32, // measured in radians
+    pub pitch : f32, // measured in radians
+    pub yaw   : f32, // measured in radians
+}
+
+pub fn simple_heading_animation(time: f32) -> Heading {
+    let t             = time as f64;
+    let step          = 0.05f64;
+    let path_size     = 15f64;
+    let circuit_speed = 0.8f64;
+
+    let xpos      = path_size * (2.0 * (t+ 0.0) * circuit_speed).sin();
+    let xpos_next = path_size * (2.0 * (t+step) * circuit_speed).sin();
+    let zpos      = 3.0 * path_size * ((t+ 0.0) * circuit_speed).cos();
+    let zpos_next = 3.0 * path_size * ((t+step) * circuit_speed).cos();
+
+    let delta_pos = glm::vec2(xpos_next - xpos, zpos_next - zpos);
+
+    let roll  = (t * circuit_speed).cos() * 0.5;
+    let pitch = -0.175 * glm::length(&delta_pos);
+    let yaw   = PI + delta_pos.x.atan2(delta_pos.y);
+
+    Heading {
+        x     : xpos  as f32,
+        z     : zpos  as f32,
+        roll  : roll  as f32,
+        pitch : pitch as f32,
+        yaw   : yaw   as f32,
+    }
+}