1create_sub_zbuffer(3)           Allegro manual           create_sub_zbuffer(3)
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NAME

6       create_sub_zbuffer  -  Creates a sub-z-buffer. Allegro game programming
7       library.
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SYNOPSIS

10       #include <allegro.h>
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13       ZBUFFER *create_sub_zbuffer(ZBUFFER *parent, int x, int y,  int  width,
14       int height);
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DESCRIPTION

17       Creates  a  sub-z-buffer,  ie. a z-buffer sharing drawing memory with a
18       pre-existing z-buffer, but possibly with a  different  size.  The  same
19       rules  as  for sub-bitmaps apply: the sub-z-buffer width and height can
20       extend beyond the right and bottom edges of the parent  (they  will  be
21       clipped), but the origin point must lie within the parent region.
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23       When  drawing z-buffered to a bitmap, the top left corner of the bitmap
24       is always mapped to the top left corner of  the  current  z-buffer.  So
25       this  function  is primarily useful if you want to draw to a sub-bitmap
26       and use the corresponding sub-area of the z-buffer. In other cases, eg.
27       if  you  just  want to draw to a sub-bitmap of screen (and not to other
28       parts of screen), then you would usually want to create a normal z-buf‐
29       fer  (not  sub-z-buffer) the size of the visible screen. You don't need
30       to first create a z-buffer the size of the virtual screen  and  then  a
31       sub-z-buffer of that.
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RETURN VALUE

34       Returns  the  pointer to the sub ZBUFFER or NULL if there was an error.
35       Remember to destroy the ZBUFFER once you are done  with  it,  to  avoid
36       having memory leaks.
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SEE ALSO

40       create_zbuffer(3), create_sub_bitmap(3), destroy_zbuffer(3)
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44Allegro                          version 4.4.2           create_sub_zbuffer(3)
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