// -*- C -*- function vecdiff2d(a,b) = [b[0]-a[0], b[1]-a[1]]; function vecdiff(a,b) = [b[0]-a[0], b[1]-a[1], b[2]-a[2]]; #define dsq(i) (a[i]-b[i])*(a[i]-b[i]) function dist2d(a,b) = sqrt(dsq(0) + dsq(1)); function dist(a,b) = sqrt(dsq(0) + dsq(1) + dsq(2)); #undef dsq function circle_point(c, r, alpha) = [ c[0] + r * cos(alpha), c[1] + r * sin(alpha) ]; #define d (dist2d(a,c)) #define alpha (atan2(a[1]-c[1],a[0]-c[0])) #define gamma (asin(r / d)) #define beta (alpha + 90 - gamma) function tangent_intersect_beta(c,r,a) = beta; function tangent_intersect_b(c,r,a) = circle_point(c, r, beta); #undef d #undef alpha #undef gamma #undef beta function tangents_intersect_beta(cbig,rbig,csmall,rsmall) = tangent_intersect_beta(cbig,rbig-rsmall,csmall); function reflect_in_y(p) = [-p[0], p[1]]; function angle_map_range(in,base) = in < base ? in + 360 : in >= base + 360 ? in - 360 : in;