VChangeNumberOfOverlays


 
Name
  VChangeNumberOfOverlays - changes the number of overlays that can be used
in 3DVIEWNIX.
 
Synopsis
  VChangeNumberOfOverlays(num_ovl)
  int num_ovl;
 
Description
  VChangeNumberOfOverlays changes the number of overlays and updates the
COLOR.COM file. If the number of overlays is the same as before,
VChangeNumberOfOverlays does nothing and returns. VChangeNumberOfOverlays
should be called after VCreateWindows and VCreateColormap have been called.
 
Return Value
  0 - work successfully.
  3 - write error.
 
Parameters
  num_ovl - specifies the new number of overlays. At present the maximum
	    number of overlays is one.
 
Side Effects
  Any existing overlay graphics may be destroyed.
 
Entry Conditions
  If num_ovl is not valid, or VCreateColormap is not called earlier,
VChangeNumberOfOverlays prints an error message to the standard error stream,
produces a core dump file and exits from the current process.
 
Related Functions
VCreateColormap, VCreateWindows, VLoadColormap.