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scene_gap(3)			 Allegro manual 		    scene_gap(3)

NAME
     scene_gap - Number controlling the scene z-sorting algorithm behaviour. Al-
     legro game programming library.

SYNOPSIS
     #include <allegro.h>

     extern float scene_gap;

DESCRIPTION
     This number (default value = 100.0) controls the behaviour of the z-sorting
     algorithm.  When an edge is very close to another's polygon plane, there is
     an interval of uncertainty in which you cannot tell which object is visible
     (which z is smaller). This is due to cumulative numerical errors for  edges
     that have undergone a lot of transformations and interpolations.

     The  default value means that if the 1/z values (in projected space) differ
     by only 1/100 (one percent), they are considered to be  equal  and  the  x-
     slopes  of  the  planes  are used to find out which plane is getting closer
     when we move to the right.

     Larger values means narrower margins, and increasing the chance of  missing
     true  adjacent  edges/planes.  Smaller values means larger margins, and in-
     creasing the chance of mistaking close polygons  for  adjacent  ones.   The
     value  of 100 is close to the optimum. However, the optimum shifts slightly
     with resolution, and may be application-dependent. It is here  for  you  to
     fine-tune.

SEE ALSO
     create_scene(3),	 clear_scene(3),    destroy_scene(3),	render_scene(3),
     scene_polygon3d(3)

Allegro 			  version 4.4.3 		    scene_gap(3)

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