t* A cli color picker
URI git clone git://git.codevoid.de/xpick.git
DIR Log
DIR Files
DIR Refs
DIR README
DIR LICENSE
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txpick.c (3942B)
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1 /* Copyright (c) 2020 Stefan Hagen <sh+ports[at]codevoid[dot]de>
2 *
3 * Permission to use, copy, modify, and distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
10 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
12 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
13 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15 #include <X11/Xlib.h>
16 #include <X11/Xutil.h>
17 #include <X11/cursorfont.h>
18 #include <stdio.h>
19 #include <string.h>
20 #include <unistd.h>
21 #include <stdint.h>
22
23 // original implementation in tmux colour.c
24 static int rgb_to_x256(uint8_t r, uint8_t g, uint8_t b)
25 {
26 // Calculate the nearest 0-based color index at 16 .. 231
27 #define v2ci(v) (v < 48 ? 0 : v < 115 ? 1 : (v - 35) / 40)
28 int ir = v2ci(r), ig = v2ci(g), ib = v2ci(b); // 0..5 each
29 #define color_index() (36 * ir + 6 * ig + ib) /* 0..215, lazy evaluation */
30
31 // Calculate the nearest 0-based gray index at 232 .. 255
32 int average = (r + g + b) / 3;
33 int gray_index = average > 238 ? 23 : (average - 3) / 10; // 0..23
34
35 // Calculate the represented colors back from the index
36 static const int i2cv[6] = {0, 0x5f, 0x87, 0xaf, 0xd7, 0xff};
37 int cr = i2cv[ir], cg = i2cv[ig], cb = i2cv[ib]; // r/g/b, 0..255 each
38 int gv = 8 + 10 * gray_index; // same value for r/g/b, 0..255
39
40 // Return the one which is nearer to the original input rgb value
41 #define dist_square(A,B,C, a,b,c) ((A-a)*(A-a) + (B-b)*(B-b) + (C-c)*(C-c))
42 int color_err = dist_square(cr, cg, cb, r, g, b);
43 int gray_err = dist_square(gv, gv, gv, r, g, b);
44 return color_err <= gray_err ? 16 + color_index() : 232 + gray_index;
45 }
46
47 int main(int argc, char *argv[]) {
48
49 if(argc <= 1) {
50 printf("Usage: xpick [-rhx]\n");
51 printf(" -r RGB notation RR/GG/BB\n");
52 printf(" -h HEX notation #RRGGBB\n");
53 printf(" -x XTerm nearest terminal color\n");
54 return 2;
55 }
56
57 Display *dpy = XOpenDisplay(NULL);
58 Window root = RootWindow(dpy, DefaultScreen(dpy));
59
60 Cursor cursor = XCreateFontCursor(dpy, XC_tcross);
61 XColor fgc, bgc;
62 fgc.red = -1; fgc.green = 0; fgc.blue = 0;
63 bgc.red = -1; bgc.green = -1; bgc.blue = -1;
64
65 XRecolorCursor(dpy, cursor, &fgc, &bgc);
66 XGrabPointer(dpy, root, 0, ButtonReleaseMask, GrabModeAsync, GrabModeAsync,
67 None, cursor, CurrentTime);
68
69 XEvent event;
70 XNextEvent(dpy, &event);
71 XUngrabPointer(dpy, CurrentTime);
72 XImage *ximage = XGetImage(dpy, root, event.xbutton.x_root,
73 event.xbutton.y_root, 1, 1, -1, ZPixmap);
74
75 unsigned long p = XGetPixel(ximage, 0, 0);
76 XDestroyImage(ximage);
77 XColor result; result.pixel = p;
78 XQueryColor(dpy, DefaultColormap(dpy, DefaultScreen(dpy)), &result);
79
80 int opt;
81 while((opt = getopt(argc, argv, ":hrx")) != -1){
82 switch(opt){
83 case 'h':
84 printf("#%02x%02x%02x\n",
85 result.red/256, result.green/256, result.blue/256);
86 break;
87 case 'r':
88 printf("%03d/%03d/%03d\n",
89 result.red/256, result.green/256, result.blue/256);
90 break;
91 case 'x':
92 printf("%d\n", rgb_to_x256(result.red/256, result.green/256,
93 result.blue/256));
94 break;
95 case '?': //used for some unknown opts
96 printf("Unknown option: %c\n", optopt);
97 break;
98 }
99 }
100 return 0;
101 }