ui/vnc-palette.c

   1 /*
   2  * QEMU VNC display driver: palette hash table
   3  *
   4  * From libvncserver/libvncserver/tight.c
   5  * Copyright (C) 2000, 2001 Const Kaplinsky.  All Rights Reserved.
   6  * Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
   7  *
   8  * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  26  * THE SOFTWARE.
  27  */
  28
  29 #include "vnc-palette.h"
  30
  31 static VncPaletteEntry *palette_find(const VncPalette *palette,
  32                                      uint32_t color, unsigned int hash)
  33 {
  34     VncPaletteEntry *entry;
  35
  36     QLIST_FOREACH(entry, &palette->table[hash], next) {
  37         if (entry->color == color) {
  38             return entry;
  39         }
  40     }
  41
  42     return NULL;
  43 }
  44
  45 static unsigned int palette_hash(uint32_t rgb, int bpp)
  46 {
  47     if (bpp == 16) {
  48         return ((unsigned int)(((rgb >> 8) + rgb) & 0xFF));
  49     } else {
  50         return ((unsigned int)(((rgb >> 16) + (rgb >> 8)) & 0xFF));
  51     }
  52 }
  53
  54 VncPalette *palette_new(size_t max, int bpp)
  55 {
  56     VncPalette *palette;
  57
  58     palette = g_malloc0(sizeof(*palette));
  59     palette_init(palette, max, bpp);
  60     return palette;
  61 }
  62
  63 void palette_init(VncPalette *palette, size_t max, int bpp)
  64 {
  65     memset(palette, 0, sizeof (*palette));
  66     palette->max = max;
  67     palette->bpp = bpp;
  68 }
  69
  70 void palette_destroy(VncPalette *palette)
  71 {
  72     g_free(palette);
  73 }
  74
  75 int palette_put(VncPalette *palette, uint32_t color)
  76 {
  77     unsigned int hash;
  78     unsigned int idx = palette->size;
  79     VncPaletteEntry *entry;
  80
  81     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
  82     entry = palette_find(palette, color, hash);
  83
  84     if (!entry && palette->size >= palette->max) {
  85         return 0;
  86     }
  87     if (!entry) {
  88         VncPaletteEntry *entry;
  89
  90         entry = &palette->pool[palette->size];
  91         entry->color = color;
  92         entry->idx = idx;
  93         QLIST_INSERT_HEAD(&palette->table[hash], entry, next);
  94         palette->size++;
  95     }
  96     return palette->size;
  97 }
  98
  99 int palette_idx(const VncPalette *palette, uint32_t color)
 100 {
 101     VncPaletteEntry *entry;
 102     unsigned int hash;
 103
 104     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
 105     entry = palette_find(palette, color, hash);
 106     return (entry == NULL ? -1 : entry->idx);
 107 }
 108
 109 size_t palette_size(const VncPalette *palette)
 110 {
 111     return palette->size;
 112 }
 113
 114 void palette_iter(const VncPalette *palette,
 115                   void (*iter)(int idx, uint32_t color, void *opaque),
 116                   void *opaque)
 117 {
 118     int i;
 119     VncPaletteEntry *entry;
 120
 121     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
 122         QLIST_FOREACH(entry, &palette->table[i], next) {
 123             iter(entry->idx, entry->color, opaque);
 124         }
 125     }
 126 }
 127
 128 uint32_t palette_color(const VncPalette *palette, int idx, bool *found)
 129 {
 130     int i;
 131     VncPaletteEntry *entry;
 132
 133     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
 134         QLIST_FOREACH(entry, &palette->table[i], next) {
 135             if (entry->idx == idx) {
 136                 *found = true;
 137                 return entry->color;
 138             }
 139         }
 140     }
 141
 142     *found = false;
 143     return -1;
 144 }
 145
 146 static void palette_fill_cb(int idx, uint32_t color, void *opaque)
 147 {
 148     uint32_t *colors = opaque;
 149
 150     colors[idx] = color;
 151 }
 152
 153 size_t palette_fill(const VncPalette *palette,
 154                     uint32_t colors[VNC_PALETTE_MAX_SIZE])
 155 {
 156     palette_iter(palette, palette_fill_cb, colors);
 157     return palette_size(palette);
 158 }