rom/graphics/releasepen.c

   1 /*
   2     Copyright © 1995-2001, 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     AROS_LIBBASE_EXT_DECL(struct GfxBase *,GfxBase)
  62
  63     if (NULL != cm && n < cm->Count)
  64     {
  65         struct PaletteExtra * pe = cm->PalExtra;
  66         PalExtra_AllocList_Type index;
  67
  68         ObtainSemaphore(&pe->pe_Semaphore);
  69         /* First I check whether this pen is somewhere in the
  70            free list already...
  71         */
  72
  73         index = pe->pe_FirstFree;
  74         while ((PalExtra_AllocList_Type)-1 != index)
  75         {
  76             if (index == (PalExtra_AllocList_Type)n)
  77                 goto exit;
  78
  79             index = PALEXTRA_ALLOCLIST(pe, index);
  80         }
  81
  82         /*
  83         ** It is not in the free list.
  84         ** If it is a shared pen, then I can recognize this
  85         ** by its value in the RefCnt
  86         */
  87
  88         if (0 != PALEXTRA_REFCNT(pe,n))
  89         {
  90             /*
  91             ** A SHARED pen
  92             */
  93             PALEXTRA_REFCNT(pe, n)--;
  94             if (0 == PALEXTRA_REFCNT(pe, n))
  95             {
  96                 BOOL found = FALSE;
  97                 /*
  98                 ** I can take this out if the list of shared pens
  99                 ** since this was the last application that used
 100                 ** this pen.
 101                 */
 102                 index = pe->pe_FirstShared;
 103                 if ((PalExtra_AllocList_Type)n == index)
 104                 {
 105                     found = TRUE;
 106                     /*
 107                     ** it's the very first one.
 108                     */
 109                     /*
 110                     ** Take it out of the list of entries in
 111                     ** the shared list...
 112                     */
 113                     if ((PalExtra_AllocList_Type)-1 == PALEXTRA_ALLOCLIST(pe,n))
 114                         pe->pe_FirstShared = (WORD)-1;
 115                     else
 116                         pe->pe_FirstShared = (WORD)PALEXTRA_ALLOCLIST(pe,n);
 117
 118                     pe->pe_NShared--;
 119
 120                     /*
 121                     ** ... and make it available in the list of free
 122                     ** entries.
 123                     */
 124                     PALEXTRA_ALLOCLIST(pe,n) = (PalExtra_AllocList_Type)pe->pe_FirstFree;
 125                     pe->pe_FirstFree = n;
 126                     pe->pe_NFree++;
 127                 }
 128                 else
 129                 {
 130                     do
 131                     {
 132                         if ((PalExtra_AllocList_Type)n == PALEXTRA_ALLOCLIST(pe, index))
 133                         {
 134                             found = TRUE;
 135
 136                             /*
 137                             ** Take it out of the list of shared entries
 138                             */
 139                             PALEXTRA_ALLOCLIST(pe, index) = PALEXTRA_ALLOCLIST(pe, n);
 140                             pe->pe_NShared--;
 141
 142                             /*
 143                             ** ... and make it available in the list of free
 144                             ** entries.
 145                             */
 146                             PALEXTRA_ALLOCLIST(pe, n) = (PalExtra_AllocList_Type)pe->pe_FirstFree;
 147                             pe->pe_FirstFree = n;
 148                             pe->pe_NFree++;
 149                             break;
 150                         }
 151                         else
 152                             index = PALEXTRA_ALLOCLIST(pe, index);
 153                     }
 154                     while ((PalExtra_AllocList_Type)-1 != index);
 155                 }
 156
 157             #if DEBUG
 158                 if (FALSE==found)
 159                     D(bug("Error in RealsePen() pen = %d!\n",n));
 160             #endif
 161
 162             } /* if (no further app needs this pen) */
 163
 164         } /* if (0 != PALEXTRA_REFCNT(pe,n)) */
 165         else
 166         {
 167             /* releasing an EXCLUSIVE pen */
 168             D(bug("Releasing (exclusive) pen %d\n"));
 169
 170             PALEXTRA_ALLOCLIST(pe, n) = pe->pe_FirstFree;
 171             pe->pe_FirstFree = n;
 172             pe->pe_NFree++;
 173         }
 174   exit:
 175         ReleaseSemaphore(&pe->pe_Semaphore);
 176
 177     } /* if (NULL != cm && n < cm->Count) */
 178
 179     AROS_LIBFUNC_EXIT
 180
 181 } /* ReleasePen */