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 #include <glib.h>
  31 #include <string.h>
  32
  33 static VncPaletteEntry *palette_find(const VncPalette *palette,
  34                                      uint32_t color, unsigned int hash)
  35 {
  36     VncPaletteEntry *entry;
  37
  38     QLIST_FOREACH(entry, &palette->table[hash], next) {
  39         if (entry->color == color) {
  40             return entry;
  41         }
  42     }
  43
  44     return NULL;
  45 }
  46
  47 static unsigned int palette_hash(uint32_t rgb, int bpp)
  48 {
  49     if (bpp == 16) {
  50         return ((unsigned int)(((rgb >> 8) + rgb) & 0xFF));
  51     } else {
  52         return ((unsigned int)(((rgb >> 16) + (rgb >> 8)) & 0xFF));
  53     }
  54 }
  55
  56 VncPalette *palette_new(size_t max, int bpp)
  57 {
  58     VncPalette *palette;
  59
  60     palette = g_malloc0(sizeof(*palette));
  61     palette_init(palette, max, bpp);
  62     return palette;
  63 }
  64
  65 void palette_init(VncPalette *palette, size_t max, int bpp)
  66 {
  67     memset(palette, 0, sizeof (*palette));
  68     palette->max = max;
  69     palette->bpp = bpp;
  70 }
  71
  72 void palette_destroy(VncPalette *palette)
  73 {
  74     g_free(palette);
  75 }
  76
  77 int palette_put(VncPalette *palette, uint32_t color)
  78 {
  79     unsigned int hash;
  80     unsigned int idx = palette->size;
  81     VncPaletteEntry *entry;
  82
  83     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
  84     entry = palette_find(palette, color, hash);
  85
  86     if (!entry && palette->size >= palette->max) {
  87         return 0;
  88     }
  89     if (!entry) {
  90         VncPaletteEntry *entry;
  91
  92         entry = &palette->pool[palette->size];
  93         entry->color = color;
  94         entry->idx = idx;
  95         QLIST_INSERT_HEAD(&palette->table[hash], entry, next);
  96         palette->size++;
  97     }
  98     return palette->size;
  99 }
 100
 101 int palette_idx(const VncPalette *palette, uint32_t color)
 102 {
 103     VncPaletteEntry *entry;
 104     unsigned int hash;
 105
 106     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
 107     entry = palette_find(palette, color, hash);
 108     return (entry == NULL ? -1 : entry->idx);
 109 }
 110
 111 size_t palette_size(const VncPalette *palette)
 112 {
 113     return palette->size;
 114 }
 115
 116 void palette_iter(const VncPalette *palette,
 117                   void (*iter)(int idx, uint32_t color, void *opaque),
 118                   void *opaque)
 119 {
 120     int i;
 121     VncPaletteEntry *entry;
 122
 123     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
 124         QLIST_FOREACH(entry, &palette->table[i], next) {
 125             iter(entry->idx, entry->color, opaque);
 126         }
 127     }
 128 }
 129
 130 uint32_t palette_color(const VncPalette *palette, int idx, bool *found)
 131 {
 132     int i;
 133     VncPaletteEntry *entry;
 134
 135     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
 136         QLIST_FOREACH(entry, &palette->table[i], next) {
 137             if (entry->idx == idx) {
 138                 *found = true;
 139                 return entry->color;
 140             }
 141         }
 142     }
 143
 144     *found = false;
 145     return -1;
 146 }
 147
 148 static void palette_fill_cb(int idx, uint32_t color, void *opaque)
 149 {
 150     uint32_t *colors = opaque;
 151
 152     colors[idx] = color;
 153 }
 154
 155 size_t palette_fill(const VncPalette *palette,
 156                     uint32_t colors[VNC_PALETTE_MAX_SIZE])
 157 {
 158     palette_iter(palette, palette_fill_cb, colors);
 159     return palette_size(palette);
 160 }