1 files changed, 47 insertions, 0 deletions
diff --git a/src/Math/Triangle2D.cpp b/src/Math/Triangle2D.cpp
new file mode 100644
index 0000000..035ecb3
--- /dev/null
+++ b/src/Math/Triangle2D.cpp
@@ -0,0 +1,47 @@
+/*
+ * Triangle2D.cpp
+ * 
+ * Copyright (C) 2008 Matthias Schiffer <matthias@gamezock.de>
+ * 
+ * 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 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Triangle2D.h"
+#include <cmath>
+
+namespace ZoomEdit {
+namespace Math {
+
+float Triangle2D::area() const {
+  return std::fabs((vertices[0].getY() + vertices[1].getY())*(vertices[0].getX()-vertices[1].getX())
+      + (vertices[1].getY() + vertices[2].getY())*(vertices[1].getX()-vertices[2].getX())
+      + (vertices[2].getY() + vertices[0].getY())*(vertices[2].getX()-vertices[0].getX()))/2;
+}
+
+bool Triangle2D::contains(const Vertex2D &v) const {
+  for(int i = 0; i < 3; ++i) {
+    Vector2D v1 = vertices[(i+2)%3] - vertices[(i+1)%3];
+    Vector2D v2 = vertices[i] - vertices[(i+1)%3];
+    
+    Vector2D vp = v - vertices[(i+1)%3];
+    
+    if((v1.getX()*vp.getY()-vp.getX()*v1.getY())*(v1.getX()*v2.getY()-v2.getX()*v1.getY()) < 0)
+      return false;
+  }
+  
+  return true;
+}
+
+}
+}