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-rw-r--r--geom.hpp21
1 files changed, 16 insertions, 5 deletions
diff --git a/geom.hpp b/geom.hpp
index 7ed56b7..daeedaa 100644
--- a/geom.hpp
+++ b/geom.hpp
@@ -17,6 +17,10 @@ struct vec {
return x*x + y*y;
}
+ double sqnorm() const {
+ return x*x + y*y;
+ }
+
double angle() const {
double xx = x / norm();
double a = acos(x);
@@ -79,13 +83,16 @@ struct line {
double dist(vec p) const {
// calculate distance from p to the line
- return abs(a*p.x + b*p.y + c) / sqrt(a*a + b*b);
+ 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 {
@@ -101,13 +108,17 @@ struct segment {
bool on_segment(vec p) const {
// TODO
+
// does point intersect segment?
return false;
}
double dist(vec p) const {
- //TODO
- return 1;
+ 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);
}
};