#include <math.h>
#include "interpolate.h"





//---- interpolateLinear

//  Basic linear interpolation

double interpolateLinear( double x1, double x2, double a )
{
  return x1*(1.0-a) + x2*a;
}





//---- interpolateSpringy

//  with a little wiggle at the end (portion of a sine wave, goes slightly above one, but ends at one)

double interpolateSpringy( double x1, double x2, double a )
{
  a = sin( a * 3.14159 * 0.25 * 2.6 ) / sin( 3.14159 * 0.25 * 2.6 );
  return x1*(1.0-a) + x2*a;
}