rom/hyperlayers/whichlayer.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8 #include <aros/libcall.h>
   9 #include <proto/graphics.h>
  10 #include <proto/layers.h>
  11 #include <graphics/clip.h>
  12 #include <graphics/layers.h>
  13 #include "layers_intern.h"
  14
  15 #define DEBUG 0
  16 #include <aros/debug.h>
  17 #undef kprintf
  18
  19 /*****************************************************************************
  20
  21     NAME */
  22
  23         AROS_LH3(struct Layer *, WhichLayer,
  24
  25 /*  SYNOPSIS */
  26         AROS_LHA(struct Layer_Info *, li, A0),
  27         AROS_LHA(LONG               , x,  D0),
  28         AROS_LHA(LONG               , y,  D1),
  29
  30 /*  LOCATION */
  31         struct LayersBase *, LayersBase, 22, Layers)
  32
  33 /*  FUNCTION
  34         Determines in which layer the point (x,y) is to be found.
  35         Starts with the frontmost layer.
  36
  37     INPUTS
  38         li - pointer to Layers_Info structure
  39         x  - x-coordinate
  40         y  - y-coordinate
  41
  42     RESULT
  43
  44     NOTES
  45         The function does not lock Layer_Info structure. It is
  46         the responsibility of the caller to issue the lock via
  47         LockLayerInfo()/UnlockLayerInfo()
  48
  49     EXAMPLE
  50
  51     BUGS
  52
  53     SEE ALSO
  54
  55     INTERNALS
  56
  57     HISTORY
  58         27-11-96    digulla automatically created from
  59                             layers_lib.fd and clib/layers_protos.h
  60
  61 *****************************************************************************/
  62 {
  63     AROS_LIBFUNC_INIT
  64
  65     struct Layer *l;
  66
  67     D(bug("WhichLayer(li @ $%lx, x %ld, y %ld)\n", li, x, y));
  68
  69     for
  70     (
  71         l = li->top_layer;
  72         l != NULL && !(IS_VISIBLE(l) && IsPointInRegion(l->visibleshape, x, y));
  73         l = l->back
  74     );
  75
  76     return l;
  77
  78     AROS_LIBFUNC_EXIT
  79 } /* WhichLayer */