lerp

Here’s a basic utility function I’ve been using to calculate positions in a transforming object with multiple transforms. I know the start and end positions of each transform – this returns a value in-between given a percentage.

// returns interpolated value between
// A and B, where A = 0%, and B = 100%
var lerp = function( a, b, percent ) {
  return a + percent * ( b - a );
};

lerp( -10, 180, 0.5 ) // returns 85

Lerp is short for linear interpolation.

Nothing too impressive, but I’m saving this ‘cause I forget it every time I need it.