diff options
| -rw-r--r-- | geom.hpp | 18 |
1 files changed, 15 insertions, 3 deletions
@@ -11,6 +11,10 @@ struct vec { return sqrt(x*x + y*y); } + double sqnorm() const { + return x*x + y*y; + } + double angle() const { double xx = x / norm(); double a = acos(x); @@ -81,11 +85,14 @@ struct line { // calculate distance from p to the line return abs(a*p.x+b*p.y+c)/sqrt(a*a+b*b); } + vec dir() const { + // calculate a directional vector oh the line + return vec(-b,a); + } vec proj(vec p) const { // calculate orthogonal projection of point p on the line - // TODO - return vec(0, 0); + return p-(a*p.x+b*p.y+c)/(a*a+b*b)*vec(a,b); } double angle() const { @@ -101,12 +108,17 @@ struct segment { bool on_segment(vec p) const { // TODO + // does point intersect segment? return false; } double dist(vec p) const { - + double scal = vec::dot(b-a, p-a); + double sqn = (b-a).sqnorm + if(scal > sqn)return (p-b).norm ; + if(scal < 0) return (p-a).norm ; + return line(a,b).dist(p); return 1; } }; |