Add several_interpolations_several_keys test.

tests/mod.rs

@@ -101,3 +101,30 @@ fn linear_interpolation_several_keys() {
   assert_eq!(spline.sample(10.), Some(2.));
   assert_eq!(spline.clamped_sample(11.), 4.);
 }
+
+#[test]
+fn several_interpolations_several_keys() {
+  let start = Key::new(0., 0., Interpolation::Step(0.5));
+  let k1    = Key::new(1., 5., Interpolation::Linear);
+  let k2    = Key::new(2., 0., Interpolation::Step(0.1));
+  let k3    = Key::new(3., 1., Interpolation::Linear);
+  let k4    = Key::new(10., 2., Interpolation::Linear);
+  let end   = Key::new(11., 4., Interpolation::default());
+  let spline = Spline::from_vec(vec![start, k1, k2, k3, k4, end]);
+
+  assert_eq!(spline.sample(0.), Some(0.));
+  assert_eq!(spline.sample(0.1), Some(0.));
+  assert_eq!(spline.sample(0.2), Some(0.));
+  assert_eq!(spline.sample(0.5), Some(5.));
+  assert_eq!(spline.sample(0.9), Some(5.));
+  assert_eq!(spline.sample(1.), Some(5.));
+  assert_eq!(spline.sample(1.5), Some(2.5));
+  assert_eq!(spline.sample(2.), Some(0.));
+  assert_eq!(spline.sample(2.05), Some(0.));
+  assert_eq!(spline.sample(2.1), Some(0.));
+  assert_eq!(spline.sample(2.75), Some(1.));
+  assert_eq!(spline.sample(3.), Some(1.));
+  assert_eq!(spline.sample(6.5), Some(1.5));
+  assert_eq!(spline.sample(10.), Some(2.));
+  assert_eq!(spline.clamped_sample(11.), 4.);
+}