xpick/xpick.c

102 lines
3.8 KiB
C

/* Copyright (c) 2020 Stefan Hagen <sh+ports@codevoid.de>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/cursorfont.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
// original implementation in tmux colour.c
static int rgb_to_x256(uint8_t r, uint8_t g, uint8_t b)
{
// Calculate the nearest 0-based color index at 16 .. 231
#define v2ci(v) (v < 48 ? 0 : v < 115 ? 1 : (v - 35) / 40)
int ir = v2ci(r), ig = v2ci(g), ib = v2ci(b); // 0..5 each
#define color_index() (36 * ir + 6 * ig + ib) /* 0..215, lazy evaluation */
// Calculate the nearest 0-based gray index at 232 .. 255
int average = (r + g + b) / 3;
int gray_index = average > 238 ? 23 : (average - 3) / 10; // 0..23
// Calculate the represented colors back from the index
static const int i2cv[6] = {0, 0x5f, 0x87, 0xaf, 0xd7, 0xff};
int cr = i2cv[ir], cg = i2cv[ig], cb = i2cv[ib]; // r/g/b, 0..255 each
int gv = 8 + 10 * gray_index; // same value for r/g/b, 0..255
// Return the one which is nearer to the original input rgb value
#define dist_square(A,B,C, a,b,c) ((A-a)*(A-a) + (B-b)*(B-b) + (C-c)*(C-c))
int color_err = dist_square(cr, cg, cb, r, g, b);
int gray_err = dist_square(gv, gv, gv, r, g, b);
return color_err <= gray_err ? 16 + color_index() : 232 + gray_index;
}
int main(int argc, char *argv[]) {
if(argc <= 1) {
printf("Usage: xpick [-rhx]\n");
printf(" -r RGB notation RR/GG/BB\n");
printf(" -h HEX notation #RRGGBB\n");
printf(" -x XTerm nearest terminal color\n");
return 2;
}
Display *dpy = XOpenDisplay(NULL);
Window root = RootWindow(dpy, DefaultScreen(dpy));
Cursor cursor = XCreateFontCursor(dpy, XC_tcross);
XColor fgc, bgc;
fgc.red = -1; fgc.green = 0; fgc.blue = 0;
bgc.red = -1; bgc.green = -1; bgc.blue = -1;
XRecolorCursor(dpy, cursor, &fgc, &bgc);
XGrabPointer(dpy, root, 0, ButtonReleaseMask, GrabModeAsync, GrabModeAsync,
None, cursor, CurrentTime);
XEvent event;
XNextEvent(dpy, &event);
XUngrabPointer(dpy, CurrentTime);
XImage *ximage = XGetImage(dpy, root, event.xbutton.x_root,
event.xbutton.y_root, 1, 1, -1, ZPixmap);
unsigned long p = XGetPixel(ximage, 0, 0);
XDestroyImage(ximage);
XColor result; result.pixel = p;
XQueryColor(dpy, DefaultColormap(dpy, DefaultScreen(dpy)), &result);
int opt;
while((opt = getopt(argc, argv, ":hrx")) != -1){
switch(opt){
case 'h':
printf("#%02x%02x%02x\n",
result.red/256, result.green/256, result.blue/256);
break;
case 'r':
printf("%03d/%03d/%03d\n",
result.red/256, result.green/256, result.blue/256);
break;
case 'x':
printf("%d\n", rgb_to_x256(result.red/256, result.green/256,
result.blue/256));
break;
case '?': //used for some unknown opts
printf("Unknown option: %c\n", optopt);
break;
}
}
return 0;
}