rom/graphics/initarea.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function InitArea()
   6     Lang: english
   7 */
   8 #include <exec/types.h>
   9 #include <graphics/rastport.h>
  10 #include "graphics_intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/graphics.h>
  16
  17         AROS_LH3(void, InitArea,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct AreaInfo *, areainfo  , A0),
  21         AROS_LHA(void *           , buffer    , A1),
  22         AROS_LHA(WORD             , maxvectors, D0),
  23
  24 /*  LOCATION */
  25         struct GfxBase *, GfxBase, 47, Graphics)
  26
  27 /*  FUNCTION
  28         This function initializes an areainfo structure. The size of the
  29         passed pointer to the buffer should be 5 times as large as
  30         maxvectors (in bytes).
  31
  32     INPUTS
  33         areainfo   - pointer to AreaInfo structure to be initialized
  34         buffer     - pointer to free memory to collect vectors
  35         maxvectors - maximum number of vectors the buffer can hold.
  36
  37     RESULT
  38         Areainfo structure initialized such that it will hold the vectors
  39         created by AreaMove, AreaDraw and AreaEllipse (AreaCircle).
  40
  41     NOTES
  42
  43     EXAMPLE
  44
  45     BUGS
  46
  47     SEE ALSO
  48         AreaDraw(), AreaMove(), AreaEllipse(), AreaCircle(), graphics/rastport.h
  49
  50     INTERNALS
  51
  52     HISTORY
  53
  54 *****************************************************************************/
  55 {
  56   AROS_LIBFUNC_INIT
  57
  58   areainfo->VctrTbl  = buffer;
  59   areainfo->VctrPtr  = buffer;
  60   areainfo->FlagTbl  = (BYTE *)(((IPTR)buffer)+(2*sizeof(WORD)*maxvectors));
  61   areainfo->FlagPtr  = (BYTE *)(((IPTR)buffer)+(2*sizeof(WORD)*maxvectors));
  62   areainfo->Count    = 0;
  63   areainfo->MaxCount = maxvectors;
  64
  65   AROS_LIBFUNC_EXIT
  66 } /* InitArea */