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 "qemu/osdep.h"
  30 #include "vnc-palette.h"
  31
  32 static VncPaletteEntry *palette_find(const VncPalette *palette,
  33                                      uint32_t color, unsigned int hash)
  34 {
  35     VncPaletteEntry *entry;
  36
  37     QLIST_FOREACH(entry, &palette->table[hash], next) {
  38         if (entry->color == color) {
  39             return entry;
  40         }
  41     }
  42
  43     return NULL;
  44 }
  45
  46 static unsigned int palette_hash(uint32_t rgb, int bpp)
  47 {
  48     if (bpp == 16) {
  49         return ((unsigned int)(((rgb >> 8) + rgb) & 0xFF));
  50     } else {
  51         return ((unsigned int)(((rgb >> 16) + (rgb >> 8)) & 0xFF));
  52     }
  53 }
  54
  55 VncPalette *palette_new(size_t max, int bpp)
  56 {
  57     VncPalette *palette;
  58
  59     palette = g_malloc0(sizeof(*palette));
  60     palette_init(palette, max, bpp);
  61     return palette;
  62 }
  63
  64 void palette_init(VncPalette *palette, size_t max, int bpp)
  65 {
  66     memset(palette, 0, sizeof (*palette));
  67     palette->max = max;
  68     palette->bpp = bpp;
  69 }
  70
  71 void palette_destroy(VncPalette *palette)
  72 {
  73     g_free(palette);
  74 }
  75
  76 int palette_put(VncPalette *palette, uint32_t color)
  77 {
  78     unsigned int hash;
  79     unsigned int idx = palette->size;
  80     VncPaletteEntry *entry;
  81
  82     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
  83     entry = palette_find(palette, color, hash);
  84
  85     if (!entry && palette->size >= palette->max) {
  86         return 0;
  87     }
  88     if (!entry) {
  89         VncPaletteEntry *entry;
  90
  91         entry = &palette->pool[palette->size];
  92         entry->color = color;
  93         entry->idx = idx;
  94         QLIST_INSERT_HEAD(&palette->table[hash], entry, next);
  95         palette->size++;
  96     }
  97     return palette->size;
  98 }
  99
 100 int palette_idx(const VncPalette *palette, uint32_t color)
 101 {
 102     VncPaletteEntry *entry;
 103     unsigned int hash;
 104
 105     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
 106     entry = palette_find(palette, color, hash);
 107     return (entry == NULL ? -1 : entry->idx);
 108 }
 109
 110 size_t palette_size(const VncPalette *palette)
 111 {
 112     return palette->size;
 113 }
 114
 115 void palette_iter(const VncPalette *palette,
 116                   void (*iter)(int idx, uint32_t color, void *opaque),
 117                   void *opaque)
 118 {
 119     int i;
 120     VncPaletteEntry *entry;
 121
 122     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
 123         QLIST_FOREACH(entry, &palette->table[i], next) {
 124             iter(entry->idx, entry->color, opaque);
 125         }
 126     }
 127 }
 128
 129 uint32_t palette_color(const VncPalette *palette, int idx, bool *found)
 130 {
 131     int i;
 132     VncPaletteEntry *entry;
 133
 134     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
 135         QLIST_FOREACH(entry, &palette->table[i], next) {
 136             if (entry->idx == idx) {
 137                 *found = true;
 138                 return entry->color;
 139             }
 140         }
 141     }
 142
 143     *found = false;
 144     return -1;
 145 }
 146
 147 static void palette_fill_cb(int idx, uint32_t color, void *opaque)
 148 {
 149     uint32_t *colors = opaque;
 150
 151     colors[idx] = color;
 152 }
 153
 154 size_t palette_fill(const VncPalette *palette,
 155                     uint32_t colors[VNC_PALETTE_MAX_SIZE])
 156 {
 157     palette_iter(palette, palette_fill_cb, colors);
 158     return palette_size(palette);
 159 }