From 10656ae76311723d999e30fc7a14fb1d5e602969 Mon Sep 17 00:00:00 2001
From: Bruno Freitas Tissei <bft15@inf.ufpr.br>
Date: Sat, 18 May 2019 20:42:16 -0300
Subject: [PATCH] Fix geometry_functions
Signed-off-by: Bruno Freitas Tissei <bft15@inf.ufpr.br>
---
algorithms/geometry/geometry_functions.cpp | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/algorithms/geometry/geometry_functions.cpp b/algorithms/geometry/geometry_functions.cpp
index 2fc624c..1e2a51a 100644
--- a/algorithms/geometry/geometry_functions.cpp
+++ b/algorithms/geometry/geometry_functions.cpp
@@ -6,13 +6,14 @@ template <typename T>
struct Point {
T x, y;
+ Point() {}
Point(T x, T y) : x(x), y(y) {}
Point operator+(Point p) { return Point(x+p.x, y+p.y); }
Point operator-(Point p) { return Point(x-p.x, y-p.y); }
T dot(Point p) { return (x*p.x) + (y*p.y); }
- T cross(Point p) { return (x*p.y) - (y*p.y); }
+ T cross(Point p) { return (x*p.y) - (y*p.x); }
// Returns angle between this and p:
// atan2(y, x) is in the range [-180,180]. To get [0, 360],
@@ -31,6 +32,13 @@ struct Point {
return (cross(p) / (sqrt(dot(*this))*sqrt(p.dot(p))));
}
+ bool inside_triagle(Point a, Point b, Point c) {
+ bool c1 = (*this - b).cross(a - b) < 0;
+ bool c2 = (*this - c).cross(b - c) < 0;
+ bool c3 = (*this - a).cross(c - a) < 0;
+ return c1 == c2 && c1 == c3;
+ }
+
// Finds orientation of ordered triplet (a,b,c).
// Colinear (0), Clockwise (1), Counterclockwise (2)
static int orientation(Point a, Point b, Point c) {
--
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