xref: /openbmc/qemu/ui/vnc-palette.c (revision 51b24e34)
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 = qemu_mallocz(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     qemu_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 }
159