chickadee » sdl2 » point-lerp!

point-lerp point1 point2 tprocedure
point-lerp! point1 point2 t #!optional destprocedure

Efficient linear interpolation (or extrapolation) between point1 and point2. sdl2:point can only hold integer values, so the results will be truncated to integers. The results will be clamped to the range -2147483648 to 2147483647.

t is the interpolation factor (a float). Values of t between 0 and 1 will interpolate between point1 and point2. Values of t less that 0 will extrapolate beyond point1 (moving away from point2). Values greater that 1 will extrapolate beyond point2 (moving away from point1).

  • point-lerp returns a new managed sdl2:point.
  • point-lerp! modifies and returns dest. If dest is omitted, point1 is modified and returned.

These procedures are available in sdl2 egg version 0.2.0 and higher.