Codebase list i3-gaps / master libi3 / get_colorpixel.c
master

Tree @master (Download .tar.gz)

get_colorpixel.c @master — raw · history · blame 

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
/*
 * vim:ts=4:sw=4:expandtab
 *
 * i3 - an improved dynamic tiling window manager
 * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
 *
 */
#include "libi3.h"
#include "queue.h"

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
struct Colorpixel {
    char hex[8];
    uint32_t pixel;

    SLIST_ENTRY(Colorpixel) colorpixels;
};

SLIST_HEAD(colorpixel_head, Colorpixel) colorpixels;

/*
 * Returns the colorpixel to use for the given hex color (think of HTML).
 *
 * The hex_color has to start with #, for example #FF00FF.
 *
 * NOTE that get_colorpixel() does _NOT_ check the given color code for validity.
 * This has to be done by the caller.
 *
 */
uint32_t get_colorpixel(const char *hex) {
    char alpha[2];
    if (strlen(hex) == strlen("#rrggbbaa")) {
        alpha[0] = hex[7];
        alpha[1] = hex[8];
    } else {
        alpha[0] = alpha[1] = 'F';
    }

    char strgroups[4][3] = {
        {hex[1], hex[2], '\0'},
        {hex[3], hex[4], '\0'},
        {hex[5], hex[6], '\0'},
        {alpha[0], alpha[1], '\0'}};
    uint8_t r = strtol(strgroups[0], NULL, 16);
    uint8_t g = strtol(strgroups[1], NULL, 16);
    uint8_t b = strtol(strgroups[2], NULL, 16);
    uint8_t a = strtol(strgroups[3], NULL, 16);

    /* Shortcut: if our screen is true color, no need to do a roundtrip to X11 */
    if (root_screen == NULL || root_screen->root_depth == 24 || root_screen->root_depth == 32) {
        return (a << 24) | (r << 16 | g << 8 | b);
    }

    /* Lookup this colorpixel in the cache */
    struct Colorpixel *colorpixel;
    SLIST_FOREACH (colorpixel, &(colorpixels), colorpixels) {
        if (strcmp(colorpixel->hex, hex) == 0)
            return colorpixel->pixel;
    }

#define RGB_8_TO_16(i) (65535 * ((i)&0xFF) / 255)
    int r16 = RGB_8_TO_16(r);
    int g16 = RGB_8_TO_16(g);
    int b16 = RGB_8_TO_16(b);

    xcb_alloc_color_reply_t *reply;

    reply = xcb_alloc_color_reply(conn, xcb_alloc_color(conn, root_screen->default_colormap, r16, g16, b16),
                                  NULL);

    if (!reply) {
        LOG("Could not allocate color\n");
        exit(1);
    }

    uint32_t pixel = reply->pixel;
    free(reply);

    /* Store the result in the cache */
    struct Colorpixel *cache_pixel = scalloc(1, sizeof(struct Colorpixel));

    strncpy(cache_pixel->hex, hex, 7);
    cache_pixel->hex[7] = '\0';

    cache_pixel->pixel = pixel;

    SLIST_INSERT_HEAD(&(colorpixels), cache_pixel, colorpixels);

    return pixel;
}