6 /* All the helper functions needed for efficiently using XCB */
9 * Returns the colorpixel to use for the given hex color (think of HTML).
11 * The hex_color has to start with #, for example #FF00FF.
13 * NOTE that get_colorpixel() does _NOT_ check the given color code for validity.
14 * This has to be done by the caller.
17 uint32_t get_colorpixel(xcb_connection_t *conn, xcb_window_t window, char *hex) {
18 #define RGB_8_TO_16(i) (65535 * ((i) & 0xFF) / 255)
19 char strgroups[3][3] = {{hex[1], hex[2], '\0'},
20 {hex[3], hex[4], '\0'},
21 {hex[5], hex[6], '\0'}};
22 int rgb16[3] = {RGB_8_TO_16(strtol(strgroups[0], NULL, 16)),
23 RGB_8_TO_16(strtol(strgroups[1], NULL, 16)),
24 RGB_8_TO_16(strtol(strgroups[2], NULL, 16))};
26 xcb_screen_t *root_screen = xcb_setup_roots_iterator(xcb_get_setup(conn)).data;
28 xcb_colormap_t colormapId = xcb_generate_id(conn);
29 xcb_create_colormap(conn, XCB_COLORMAP_ALLOC_NONE, colormapId, window, root_screen->root_visual);
30 xcb_alloc_color_reply_t *reply = xcb_alloc_color_reply(conn,
31 xcb_alloc_color(conn, colormapId, rgb16[0], rgb16[1], rgb16[2]), NULL);
34 printf("color fail\n");
38 uint32_t pixel = reply->pixel;
40 xcb_free_colormap(conn, colormapId);