98 lines
2.8 KiB
C
98 lines
2.8 KiB
C
/*
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geometry.h - a place for geometry helpers
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Part of Grbl
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Copyright (c) 2009 Simen Svale Skogsrud
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Grbl is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Grbl is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Grbl. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "geometry.h"
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#include <avr/io.h>
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#include <math.h>
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#include <stdlib.h>
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// Find the angle in radians of deviance from the positive y axis. negative angles to the left of y-axis,
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// positive to the right.
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double theta(double x, double y)
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{
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double theta = atan(x/fabs(y));
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if (y>0) {
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return(theta);
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} else {
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if (theta>0)
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{
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return(M_PI-theta);
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} else {
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return(-M_PI-theta);
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}
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}
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}
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/*
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Quadrants of the circle
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+---- 0 ----+ 0 - y is always positive and |x| < |y|
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| | 1 - x is always positive and |x| > |y|
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| | 2 - y is always negative and |x| < |y|
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3 + 1 3 - x is always negative and |x| > |y|
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| |
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+---- 2 ----+
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*/
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// Find the quadrant of the coordinate
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int quadrant_of_the_circle(int32_t x, int32_t y) {
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if (abs(x)<abs(y)){
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if (y>0) {
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return(0);
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} else {
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return(2);
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}
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} else {
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if (x>0) {
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return(1);
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} else {
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return(3);
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}
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}
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}
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// Very specialized helper to calculate the amount of steps to travel in the given quadrant of a circle provided the
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// axial direction of the quadrant, the angular_direction of travel (-1 or +1) and amount of steps in one half quadrant
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// of the circle.
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uint32_t steps_in_partial_quadrant(int32_t x, int32_t y, int quadrant, int angular_direction,
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int32_t steps_in_half_quadrant) {
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if (quadrant_horizontal(quadrant)) { // A horizontal quadrant
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if ((angular_direction == 1) ^ (quadrant == 2)) {
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return(steps_in_half_quadrant-x);
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} else {
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return(x+steps_in_half_quadrant);
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}
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} else { // A vertical quadrant
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if ((angular_direction == 1) ^ (quadrant == 3)) {
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return(steps_in_half_quadrant-y);
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} else {
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return(y+steps_in_half_quadrant);
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}
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}
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}
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// Counts the amount of full quadrants between quadrant_start and quadrant_target along the angular_direction
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int full_quadrants_between(int quadrant_start, int quadrant_target, int angular_direction) {
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int diff = angular_direction*(quadrant_target-quadrant_start);
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if (diff <= 0) { diff += 4; }
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return (diff-1);
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}
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