/* * coord.c - Coordinate representation and basic operations * * Written 2009, 2010, 2016 by Werner Almesberger * Copyright 2009, 2010, 2016 by Werner Almesberger * Copyright 2016, Erich Heinzle (gEDA additions) * * This program 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 2 of the License, or * (at your option) any later version. */ #include #include "util.h" #include "coord.h" /* ----- unit conversion --------------------------------------------------- */ double mm_to_mil(double mm, int exponent) { return mm*pow(MIL_IN_MM, -exponent); } double mil_to_mm(double mil, int exponent) { return mil*pow(MIL_IN_MM, exponent); } double um_to_mm(double um, int exponent) { return um*pow(UM_IN_MM, exponent); } /* ----- convert internal units to best external unit ---------------------- */ double units_to_best(unit_type u, int *mm) { /* * For finding the best choice, we work with deci-micrometers and * micro-inches. The conversion to "dum" is actually a no-op, but that * may change if we ever pick a different internal unit than 0.1 um. */ long dum = round(units_to_mm(u)*10000.0); long uin = round(units_to_mil(u)*1000.0); /* remove trailing zeroes */ while (dum && !(dum % 10)) dum /= 10; while (uin && !(uin % 10)) uin /= 10; /* ceil(log10(dum)) <= ceil(log10(uin)) ? */ while (dum && uin) { dum /= 10; uin /= 10; } if (!dum) { *mm = 1; return units_to_mm(u); } else { *mm = 0; return units_to_mil(u); } } /* ----- vector operations ------------------------------------------------- */ struct coord normalize(struct coord v, unit_type len) { double f; f = len/hypot(v.x, v.y); v.x *= f; v.y *= f; return v; } struct coord rotate(struct coord v, double angle) { double rad = M_PI*angle/180.0; struct coord res; res.x = v.x*cos(rad)-v.y*sin(rad); res.y = v.y*cos(rad)+v.x*sin(rad); return res; } struct coord add_vec(struct coord a, struct coord b) { a.x += b.x; a.y += b.y; return a; } struct coord sub_vec(struct coord a, struct coord b) { a.x -= b.x; a.y -= b.y; return a; } struct coord neg_vec(struct coord v) { v.x = -v.x; v.y = -v.y; return v; } /* ----- point on circle --------------------------------------------------- */ struct coord rotate_r(struct coord c, unit_type r, double angle) { struct coord p; angle = angle/180.0*M_PI; p.x = c.x+r*cos(angle); p.y = c.y+r*sin(angle); return p; } double theta_vec(struct coord v) { double a; a = atan2(v.y, v.x)/M_PI*180.0; if (a < 0) a += 360.0; return a; } double theta(struct coord c, struct coord p) { p.x -= c.x; p.y -= c.y; return theta_vec(p); } /* ----- sorting coordinates ----------------------------------------------- */ void sort_coord(struct coord *min, struct coord *max) { if (min->x > max->x) SWAP(min->x, max->x); if (min->y > max->y) SWAP(min->y, max->y); } /* ----- distance calculations --------------------------------------------- */ unit_type dist_point(struct coord a, struct coord b) { return hypot(a.x-b.x, a.y-b.y); } static unit_type dist_line_xy(unit_type px, unit_type py, unit_type ax, unit_type ay, unit_type bx, unit_type by) { unit_type d_min, d; double a, f; d_min = hypot(ax-px, ay-py); d = hypot(bx-px, by-py); if (d < d_min) d_min = d; if (ax != bx || ay != by) { /* * We make a the line vector from point B and b the vector from * B to point P. Then we calculate the projection of b on a. */ ax -= bx; ay -= by; bx = px-bx; by = py-by; a = hypot(ax, ay); f = ((double) ax*bx+(double) ay*by)/a/a; if (f >= 0 && f <= 1) { bx -= f*ax; by -= f*ay; d = hypot(bx, by); if (d < d_min) d_min = d; } } return d_min; } unit_type dist_line(struct coord p, struct coord a, struct coord b) { return dist_line_xy(p.x, p.y, a.x, a.y, b.x, b.y); } unit_type dist_rect(struct coord p, struct coord a, struct coord b) { unit_type d_min, d; d_min = dist_line_xy(p.x, p.y, a.x, a.y, b.x, a.y); d = dist_line_xy(p.x, p.y, a.x, a.y, a.x, b.y); if (d < d_min) d_min = d; d = dist_line_xy(p.x, p.y, a.x, b.y, b.x, b.y); if (d < d_min) d_min = d; d = dist_line_xy(p.x, p.y, b.x, a.y, b.x, b.y); if (d < d_min) d_min = d; return d_min; } int inside_rect(struct coord p, struct coord a, struct coord b) { sort_coord(&a, &b); if (p.x < a.x || p.x > b.x) return 0; if (p.y < a.y || p.y > b.y) return 0; return 1; } unit_type dist_circle(struct coord p, struct coord c, unit_type r) { unit_type d; d = hypot(p.x-c.x, p.y-c.y); return fabs(d-r); }