Move the Knot struct out of Spline

It doesn't depend on the degree of the spline, so this will generate less
different types and make it easier to create splines of different degrees
from the same knots.

diff --git a/source/interpolate/spline.h b/source/interpolate/spline.h
index 67c8df07d9b9e24904b868ab1950762d7d95c58c..c801188e695cfb4f1c6a51c75368332ad5af53e9 100644 (file)
--- a/source/interpolate/spline.h
+++ b/source/interpolate/spline.h
@@ -3,6 +3,7 @@
 
 #include <algorithm>
 #include <vector>
+#include "knot.h"
 #include "polynomial.h"
 
 namespace Msp {
@@ -24,6 +25,17 @@ struct SplineValue<T, 1>
        static Type make(const T *v) { return *v; }
 };
 
+template<typename T, unsigned N>
+struct SplineKnot
+{
+       typedef typename SplineValue<T, N>::Type Value;
+       T x;
+       Value y;
+
+       SplineKnot(): x(T()) { }
+       SplineKnot(T x_, const Value &y_): x(x_), y(y_) { }
+};
+
 /**
 Stores a spline of degree D.  It is a piecewise polynomial function with value
 continuity.  Derivatives are not guaranteed to be continuous.
@@ -39,15 +51,7 @@ class Spline
 {
 public:
        typedef typename SplineValue<T, N>::Type Value;
-
-       struct Knot
-       {
-               T x;
-               Value y;
-
-               Knot(): x(T()) { }
-               Knot(T x_, const Value &y_): x(x_), y(y_) { }
-       };
+       typedef SplineKnot<T, N> Knot;
 
        struct Segment
        {