Interpolation type constants are in the form: IP_<EQUATION>_<EASING>
The equation type can be any of the following:
2X - Quadratic 3X - Cubic 4X - Quartic 5X - Quintic SIN - Sine
The easing type can be any of the following:
LINEAR - Linear from start to end. ACCEL - Start slow, speed up. DECEL - Start fast, slow to stop. SMOOTH - Start slow, accelerate, decelerate, slow to stop. Combination of ACCEL and DECEL. SMOOTH_INV - Start slow, speed up, stop halfway, start fast, slow to stop. Inverted SMOOTH (DECEL then ACCEL)
List of all valid combinations:
IP_LINEAR IP_2X_ACCEL IP_3X_ACCEL IP_4X_ACCEL IP_5X_ACCEL IP_2X_DECEL IP_3X_DECEL IP_4X_DECEL IP_5X_DECEL IP_2X_SMOOTH IP_3X_SMOOTH IP_4X_SMOOTH IP_5X_SMOOTH IP_2X_SMOOTH_INV IP_3X_SMOOTH_INV IP_4X_SMOOTH_INV IP_5X_SMOOTH_INV IP_SIN_ACCEL IP_SIN_DECEL IP_SIN_SMOOTH IP_SIN_SMOOTH_INV