rom/graphics/releasepen.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Release a pen previously allocated.
   6     Lang: english
   7 */
   8 #include <aros/debug.h>
   9
  10 #include "graphics_intern.h"
  11 #include <graphics/view.h>
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16         #include <proto/graphics.h>
  17
  18         AROS_LH2(void, ReleasePen,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct ColorMap *, cm, A0),
  22         AROS_LHA(ULONG            , n , D0),
  23
  24 /*  LOCATION */
  25         struct GfxBase *, GfxBase, 158, Graphics)
  26
  27 /*  FUNCTION
  28         Release a pen that was previously allocated as an exclusive
  29         or shared pen by the application. Any other application can
  30         then obtain this pen and make changes to the color register
  31         entries.
  32
  33
  34     INPUTS
  35         cm - ColorMap structure where the pen was allocated
  36         n  - The number of the pen
  37
  38     RESULT
  39         An exclusive pen is deallocated for other applications to use.
  40         A shared pen is only completely deallocated if no other
  41         application is using it anymore.
  42
  43     NOTES
  44
  45     EXAMPLE
  46
  47     BUGS
  48
  49     SEE ALSO
  50
  51     INTERNALS
  52
  53     HISTORY
  54
  55 *****************************************************************************/
  56 {
  57     AROS_LIBFUNC_INIT
  58
  59     if (NULL != cm && n < cm->Count)
  60     {
  61         struct PaletteExtra * pe = cm->PalExtra;
  62         PalExtra_AllocList_Type index;
  63
  64         ObtainSemaphore(&pe->pe_Semaphore);
  65         /* First I check whether this pen is somewhere in the
  66            free list already...
  67         */
  68
  69         index = pe->pe_FirstFree;
  70         while ((PalExtra_AllocList_Type)-1 != index)
  71         {
  72             if (index == (PalExtra_AllocList_Type)n)
  73                 goto exit;
  74
  75             index = PALEXTRA_ALLOCLIST(pe, index);
  76         }
  77
  78         /*
  79         ** It is not in the free list.
  80         ** If it is a shared pen, then I can recognize this
  81         ** by its value in the RefCnt
  82         */
  83
  84         if (0 != PALEXTRA_REFCNT(pe,n))
  85         {
  86             /*
  87             ** A SHARED pen
  88             */
  89             PALEXTRA_REFCNT(pe, n)--;
  90             if (0 == PALEXTRA_REFCNT(pe, n))
  91             {
  92                 D(BOOL found = FALSE);
  93                 /*
  94                 ** I can take this out if the list of shared pens
  95                 ** since this was the last application that used
  96                 ** this pen.
  97                 */
  98                 index = pe->pe_FirstShared;
  99                 if ((PalExtra_AllocList_Type)n == index)
 100                 {
 101                     D(found = TRUE);
 102                     /*
 103                     ** it's the very first one.
 104                     */
 105                     /*
 106                     ** Take it out of the list of entries in
 107                     ** the shared list...
 108                     */
 109                     if ((PalExtra_AllocList_Type)-1 == PALEXTRA_ALLOCLIST(pe,n))
 110                         pe->pe_FirstShared = (WORD)-1;
 111                     else
 112                         pe->pe_FirstShared = (WORD)PALEXTRA_ALLOCLIST(pe,n);
 113
 114                     pe->pe_NShared--;
 115
 116                     /*
 117                     ** ... and make it available in the list of free
 118                     ** entries.
 119                     */
 120                     PALEXTRA_ALLOCLIST(pe,n) = (PalExtra_AllocList_Type)pe->pe_FirstFree;
 121                     pe->pe_FirstFree = n;
 122                     pe->pe_NFree++;
 123                 }
 124                 else
 125                 {
 126                     do
 127                     {
 128                         if ((PalExtra_AllocList_Type)n == PALEXTRA_ALLOCLIST(pe, index))
 129                         {
 130                             D(found = TRUE);
 131
 132                             /*
 133                             ** Take it out of the list of shared entries
 134                             */
 135                             PALEXTRA_ALLOCLIST(pe, index) = PALEXTRA_ALLOCLIST(pe, n);
 136                             pe->pe_NShared--;
 137
 138                             /*
 139                             ** ... and make it available in the list of free
 140                             ** entries.
 141                             */
 142                             PALEXTRA_ALLOCLIST(pe, n) = (PalExtra_AllocList_Type)pe->pe_FirstFree;
 143                             pe->pe_FirstFree = n;
 144                             pe->pe_NFree++;
 145                             break;
 146                         }
 147                         else
 148                             index = PALEXTRA_ALLOCLIST(pe, index);
 149                     }
 150                     while ((PalExtra_AllocList_Type)-1 != index);
 151                 }
 152
 153             #if DEBUG
 154                 if (!found)
 155                     D(bug("Error in ReleasePen() pen = %d!\n",n));
 156             #endif
 157
 158             } /* if (no further app needs this pen) */
 159
 160         } /* if (0 != PALEXTRA_REFCNT(pe,n)) */
 161         else
 162         {
 163             /* releasing an EXCLUSIVE pen */
 164             D(bug("Releasing (exclusive) pen %d\n"));
 165
 166             PALEXTRA_ALLOCLIST(pe, n) = pe->pe_FirstFree;
 167             pe->pe_FirstFree = n;
 168             pe->pe_NFree++;
 169         }
 170   exit:
 171         ReleaseSemaphore(&pe->pe_Semaphore);
 172
 173     } /* if (NULL != cm && n < cm->Count) */
 174
 175     AROS_LIBFUNC_EXIT
 176
 177 } /* ReleasePen */