fade_interpolate - Man Page

#include <allegro.h>

void fade_interpolate(const PALETTE source, const PALETTE dest, PALETTE output, int pos, int from, int to);

Calculates a temporary palette part way between source and dest,  returning it in the output parameter. The position between the two  extremes is specified by the pos value: 0 returns an exact copy of  source, 64 returns dest, 32 returns a palette half way between the two,  etc. This routine only affects colors between from and to (inclusive:  pass 0 and 255 to interpolate the entire palette).

fade_in(3), fade_out(3), fade_from(3)

fade_from(3), fade_in(3), fade_out(3).