[bspwm] split-preselection using mouse

pointer_region.sh

#!/bin/sh

## This script allows to preselect the next window split
## direction for bspwm with the mouse.
##
## Usage Example (add to .sxhkdrc):
## super + ctrl + {_,shift + } button3
##  bspc node {,$(xdotool getmouselocation | cut -d ':' -f 5)} -p $(~/.config/bspwm/pointer_region.sh {active,all})
##
## Author: notuxic
## License: CC0


## Load all relevant values into environmental variables,
## abort if moused-over window is not active window

eval $(xdotool getmouselocation --shell)

if [ x"$1" != x"all" ] && [ "$WINDOW" != "$(xdotool getactivewindow)" ]
then
	echo "none"
	exit 1
fi

WININFO="$(xwininfo -id "$WINDOW")"
WIDTH="$(echo "$WININFO" | sed -n 's/[[:blank:]]*Width: \([0-9]*\)[[:blank:]]*/\1/p')"
HEIGHT="$(echo "$WININFO" | sed -n 's/[[:blank:]]*Height: \([0-9]*\)[[:blank:]]*/\1/p')"
RX="$(echo "$WININFO" | sed -n 's/[[:blank:]]*Absolute.*X: \([0-9]*\)[[:blank:]]*/\1/p')"
RY="$(echo "$WININFO" | sed -n 's/[[:blank:]]*Absolute.*Y: \([0-9]*\)[[:blank:]]*/\1/p')"


## Define bc script and pass environmental variables

SCRIPT=$(cat << EOS

## load ENV variables into bc variables

pointer_x = $X;
pointer_y = $Y;
corner_lu_x = $RX;
corner_lu_y = $RY;
window_width = $WIDTH;
window_height = $HEIGHT;


## Implement atan2, range: (0; 2 * pi]

pi = 4 * a(1);

define atan2(y, x) {
	if (x > 0 && y >= 0) {
		return a(y / x);
	}
	if (x > 0 && y < 0) {
		return (2 * pi + a(y / x));
	}
	if (x < 0) {
		return (a(y / x) + pi);
	}
	if (x == 0 && y > 0) {
		return (pi / 2);
	}
	if (x == 0 && y < 0) {
		return (3 * pi / 2);
	}
}


## Calculate coords of origin (ie. center of window)

origin_x = corner_lu_x + ( window_width / 2);
origin_y = corner_lu_y + ( window_height / 2);


## Translate mouse coords and upper-left window corner coords
## to cartesian coordinate system with center of moused-over
## window as origin

pointer_x = pointer_x - origin_x;
pointer_y = origin_y - pointer_y;

corner_lu_x = corner_lu_x - origin_x;
corner_lu_y = origin_y - corner_lu_y;


## Translate cartesian coords to polar coords (only calculating
## the angles), and calculate angles of remaining window corners

pointer_theta = atan2(pointer_y, pointer_x);
corner_lu_theta = atan2(corner_lu_y, corner_lu_x);
corner_ru_theta = atan2(corner_lu_y, - corner_lu_x);
corner_ll_theta = corner_ru_theta + pi;
corner_rl_theta = corner_lu_theta + pi;


## Print cardinal direction (north, east, south, west) depending on
## pointer angle in relation to corner angles.

if (pointer_theta >= corner_ru_theta && pointer_theta < corner_lu_theta) {
	print "north";
}
if (pointer_theta >= corner_lu_theta && pointer_theta < corner_ll_theta) {
	print "west";
}
if (pointer_theta >= corner_ll_theta && pointer_theta < corner_rl_theta) {
	print "south";
}
if (pointer_theta >= corner_rl_theta || pointer_theta < corner_ru_theta) {
	print "east";
}


EOS
)


## Execute bc script

echo "$SCRIPT" | bc -l