debian man page for clear_zbuffer

clear_zbuffer(3alleg4)						  Allegro manual					    clear_zbuffer(3alleg4)

NAME
       clear_zbuffer - Writes a depth value into the given Z-buffer. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       void clear_zbuffer(ZBUFFER *zbuf, float z);

DESCRIPTION
       Writes  z  into the given Z-buffer (0 means far away). This function should be used to initialize the Z-buffer before each frame. Actually,
       low-level routines compare depth of the current pixel with 1/z: for example, if you want to clip polygons farther than 10,  you	must  call
       clear_zbuffer(zbuf, 0.1).

SEE ALSO
       create_zbuffer(3alleg4), set_zbuffer(3alleg4), destroy_zbuffer(3alleg4), exzbuf(3alleg4)

Allegro 							   version 4.4.2					    clear_zbuffer(3alleg4)