Merge branch 'master' of https://github.com/virtualritz/uniform-cubic-splines into master

Author: virtualritz

README.md

@@ -1,2 +1,36 @@
-# simple-spline
-Simple cubic spline evaluation in Rust
+## Uniform Cubic Spline Interpolation & Inversion
+
+This crate supports the following types of splines:
+* [B-spline](https://en.wikipedia.org/wiki/B-spline)
+* [Bezier](https://en.wikipedia.org/wiki/Composite_B%C3%A9zier_curve)
+* [Catmull-Rom](https://en.wikipedia.org/wiki/Cubic_Hermite_spline#Catmull%E2%80%93Rom_spline)
+* [Hermite](https://en.wikipedia.org/wiki/Cubic_Hermite_spline)
+* Linear
+* Power
+
+If you come from a background of shading languages used in offline
+rendering this crate should feel like home.
+
+The code is a Rust port of the resp. implementation found in the
+[Open Shading Language](https://github.com/imageworks/OpenShadingLanguage)
+C++ source.
+
+# Example
+Using a combination of `spline()` and `spline_inverse()` it is
+possible to compute a full spline-with-nonuniform-abscissæ:
+```rust
+use uniform_cubic_splines::{
+    spline, spline_inverse, basis::{CatmullRom, Linear}
+};
+
+// We want to evaluate the spline at knot value 0.3.
+let x = 0.3;
+
+let values = [0.0, 0.0, 1.3, 4.2, 6.4, 6.4];
+let knots = [0.0, 0.0, 0.1, 0.3, 1.0, 1.0];
+
+let v = spline_inverse::<Linear, _>(x, &knots).unwrap();
+let y = spline::<CatmullRom, _, _>(v, &values);
+
+assert!(y - 4.2 < 1e-6);
+```