fade_in - Gradually fades the palette from black. Allegro game programming library.

       Fades  gradually from a black screen to the specified palette. The speed is from 1 (the slowest) up to 64
       (instantaneous).

       Note that this function will block your game while the fade  is  in  effect,  and  it  won't  work  right
       visually if you are not in an 8 bit color depth resolution.

       fade_in - Gradually fades the palette from black. Allegro game programming library.

fade_out(3alleg4), fade_from(3alleg4), fade_interpolate(3alleg4), fade_in_range(3alleg4)

Allegro                                           version 4.4.3                                 fade_in(3alleg4)

#include<allegro.h>voidfade_in(constPALETTEp,intspeed);