xref: /openbmc/qemu/ui/vnc-palette.c (revision bb302772)
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         entry = &palette->pool[palette->size];
90         entry->color = color;
91         entry->idx = idx;
92         QLIST_INSERT_HEAD(&palette->table[hash], entry, next);
93         palette->size++;
94     }
95     return palette->size;
96 }
97 
98 int palette_idx(const VncPalette *palette, uint32_t color)
99 {
100     VncPaletteEntry *entry;
101     unsigned int hash;
102 
103     hash = palette_hash(color, palette->bpp) % VNC_PALETTE_HASH_SIZE;
104     entry = palette_find(palette, color, hash);
105     return (entry == NULL ? -1 : entry->idx);
106 }
107 
108 size_t palette_size(const VncPalette *palette)
109 {
110     return palette->size;
111 }
112 
113 void palette_iter(const VncPalette *palette,
114                   void (*iter)(int idx, uint32_t color, void *opaque),
115                   void *opaque)
116 {
117     int i;
118     VncPaletteEntry *entry;
119 
120     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
121         QLIST_FOREACH(entry, &palette->table[i], next) {
122             iter(entry->idx, entry->color, opaque);
123         }
124     }
125 }
126 
127 uint32_t palette_color(const VncPalette *palette, int idx, bool *found)
128 {
129     int i;
130     VncPaletteEntry *entry;
131 
132     for (i = 0; i < VNC_PALETTE_HASH_SIZE; i++) {
133         QLIST_FOREACH(entry, &palette->table[i], next) {
134             if (entry->idx == idx) {
135                 *found = true;
136                 return entry->color;
137             }
138         }
139     }
140 
141     *found = false;
142     return -1;
143 }
144 
145 static void palette_fill_cb(int idx, uint32_t color, void *opaque)
146 {
147     uint32_t *colors = opaque;
148 
149     colors[idx] = color;
150 }
151 
152 size_t palette_fill(const VncPalette *palette,
153                     uint32_t colors[VNC_PALETTE_MAX_SIZE])
154 {
155     palette_iter(palette, palette_fill_cb, colors);
156     return palette_size(palette);
157 }
158