sineIn            167 src/swfc-history.c 		case IF_SINE_IN: return sineIn(fraction, p1, p2 - p1);
sineIn            148 src/swfc-interpolation.c     return sineIn(1 - fraction, start + delta, -delta);
sineIn            154 src/swfc-interpolation.c         return sineIn(2 * fraction, start, delta / 2);
sineIn             94 src/swfc-interpolation.h float sineIn(float fraction, float start, float delta);