39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
/*
|
|
geometry.h - a place for geometry helpers
|
|
Part of Grbl
|
|
|
|
Copyright (c) 2009 Simen Svale Skogsrud
|
|
|
|
Grbl is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
Grbl is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with Grbl. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <math.h>
|
|
|
|
// Find the angle in radians of deviance from the positive y axis. negative angles to the left of y-axis,
|
|
// positive to the right.
|
|
double theta(double x, double y)
|
|
{
|
|
double theta = atan(x/fabs(y));
|
|
if (y>0) {
|
|
return(theta);
|
|
} else {
|
|
if (theta>0)
|
|
{
|
|
return(M_PI-theta);
|
|
} else {
|
|
return(-M_PI-theta);
|
|
}
|
|
}
|
|
}
|