Provided by: allegro4-doc_4.4.2-4_all 

NAME
fade_interpolate - Calculates a new palette interpolated between two others. Allegro game programming
library.
SYNOPSIS
#include <allegro.h>
void fade_interpolate(const PALETTE source, const PALETTE dest, PALETTE output, int pos, int from, int
to);
DESCRIPTION
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).
SEE ALSO
fade_in(3alleg4), fade_out(3alleg4), fade_from(3alleg4)
Allegro version 4.4.2 fade_interpolate(3alleg4)