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 "graphics_intern.h"
   9 #include <graphics/view.h>
  10 #ifdef DEBUG
  11 #undef DEBUG
  12 #endif
  13 #define DEBUG 0
  14 #include <aros/debug.h>
  15
  16 /*****************************************************************************
  17
  18     NAME */
  19         #include <clib/graphics_protos.h>
  20
  21         AROS_LH2(void, ReleasePen,
  22
  23 /*  SYNOPSIS */
  24         AROS_LHA(struct ColorMap *, cm, A0),
  25         AROS_LHA(ULONG            , n , D0),
  26
  27 /*  LOCATION */
  28         struct GfxBase *, GfxBase, 158, Graphics)
  29
  30 /*  FUNCTION
  31         Release a pen that was previously allocated as an exclusive
  32         or shared pen by the application. Any other application can
  33         then obtain this pen and make changes to the color register
  34         entries.
  35
  36
  37     INPUTS
  38         cm - ColorMap structure where the pen was allocated
  39         n  - The number of the pen
  40
  41     RESULT
  42         An exclusive pen is deallocated for other applications to use.
  43         A shared pen is only completely deallocated if no other
  44         application is using it anymore.
  45
  46     NOTES
  47
  48     EXAMPLE
  49
  50     BUGS
  51
  52     SEE ALSO
  53
  54     INTERNALS
  55
  56     HISTORY
  57
  58 *****************************************************************************/
  59 {
  60     AROS_LIBFUNC_INIT
  61
  62     if (NULL != cm && n < cm->Count)
  63     {
  64         struct PaletteExtra * pe = cm->PalExtra;
  65         PalExtra_AllocList_Type index;
  66
  67         ObtainSemaphore(&pe->pe_Semaphore);
  68         /* First I check whether this pen is somewhere in the
  69            free list already...
  70         */
  71
  72         index = pe->pe_FirstFree;
  73         while ((PalExtra_AllocList_Type)-1 != index)
  74         {
  75             if (index == (PalExtra_AllocList_Type)n)
  76                 goto exit;
  77
  78             index = PALEXTRA_ALLOCLIST(pe, index);
  79         }
  80
  81         /*
  82         ** It is not in the free list.
  83         ** If it is a shared pen, then I can recognize this
  84         ** by its value in the RefCnt
  85         */
  86
  87         if (0 != PALEXTRA_REFCNT(pe,n))
  88         {
  89             /*
  90             ** A SHARED pen
  91             */
  92             PALEXTRA_REFCNT(pe, n)--;
  93             if (0 == PALEXTRA_REFCNT(pe, n))
  94             {
  95                 BOOL found = FALSE;
  96                 /*
  97                 ** I can take this out if the list of shared pens
  98                 ** since this was the last application that used
  99                 ** this pen.
 100                 */
 101                 index = pe->pe_FirstShared;
 102                 if ((PalExtra_AllocList_Type)n == index)
 103                 {
 104                     found = TRUE;
 105                     /*
 106                     ** it's the very first one.
 107                     */
 108                     /*
 109                     ** Take it out of the list of entries in
 110                     ** the shared list...
 111                     */
 112                     if ((PalExtra_AllocList_Type)-1 == PALEXTRA_ALLOCLIST(pe,n))
 113                         pe->pe_FirstShared = (WORD)-1;
 114                     else
 115                         pe->pe_FirstShared = (WORD)PALEXTRA_ALLOCLIST(pe,n);
 116
 117                     pe->pe_NShared--;
 118
 119                     /*
 120                     ** ... and make it available in the list of free
 121                     ** entries.
 122                     */
 123                     PALEXTRA_ALLOCLIST(pe,n) = (PalExtra_AllocList_Type)pe->pe_FirstFree;
 124                     pe->pe_FirstFree = n;
 125                     pe->pe_NFree++;
 126                 }
 127                 else
 128                 {
 129                     do
 130                     {
 131                         if ((PalExtra_AllocList_Type)n == PALEXTRA_ALLOCLIST(pe, index))
 132                         {
 133                             found = TRUE;
 134
 135                             /*
 136                             ** Take it out of the list of shared entries
 137                             */
 138                             PALEXTRA_ALLOCLIST(pe, index) = PALEXTRA_ALLOCLIST(pe, n);
 139                             pe->pe_NShared--;
 140
 141                             /*
 142                             ** ... and make it available in the list of free
 143                             ** entries.
 144                             */
 145                             PALEXTRA_ALLOCLIST(pe, n) = (PalExtra_AllocList_Type)pe->pe_FirstFree;
 146                             pe->pe_FirstFree = n;
 147                             pe->pe_NFree++;
 148                             break;
 149                         }
 150                         else
 151                             index = PALEXTRA_ALLOCLIST(pe, index);
 152                     }
 153                     while ((PalExtra_AllocList_Type)-1 != index);
 154                 }
 155
 156             #if DEBUG
 157                 if (!found)
 158                     D(bug("Error in ReleasePen() pen = %d!\n",n));
 159             #endif
 160
 161             } /* if (no further app needs this pen) */
 162
 163         } /* if (0 != PALEXTRA_REFCNT(pe,n)) */
 164         else
 165         {
 166             /* releasing an EXCLUSIVE pen */
 167             D(bug("Releasing (exclusive) pen %d\n"));
 168
 169             PALEXTRA_ALLOCLIST(pe, n) = pe->pe_FirstFree;
 170             pe->pe_FirstFree = n;
 171             pe->pe_NFree++;
 172         }
 173   exit:
 174         ReleaseSemaphore(&pe->pe_Semaphore);
 175
 176     } /* if (NULL != cm && n < cm->Count) */
 177
 178     AROS_LIBFUNC_EXIT
 179
 180 } /* ReleasePen */