Function InterpolatePoints

libraries/lib-mixer/Envelope.cpp:1151–1158

A few helper functions to make the code below more readable.

// A few helper functions to make the code below more readable.
static double InterpolatePoints(double y1, double y2, double factor, bool logarithmic)
{
   if(logarithmic)
      // you can use any base you want, it doesn't change the result
      return exp(log(y1) * (1.0 - factor) + log(y2) * factor);
   else
      return y1 * (1.0 - factor) + y2 * factor;
}
static double IntegrateInterpolated(double y1, double y2, double time, bool logarithmic)
{
   // Calculates: integral(interpolate(y1, y2, x), x = 0 .. time)