xref: /openbmc/qemu/ui/vnc-palette.c (revision d38ea87a)
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 #include <glib.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 }
161