added ball to ball collisions

[physics.git] / src / Vector2.cpp

diff --git a/src/Vector2.cpp b/src/Vector2.cpp
index 4d4b85a..d13ea95 100644 (file)
--- a/src/Vector2.cpp
+++ b/src/Vector2.cpp
@@ -1,3 +1,20 @@
+/*
+ *  Copyright (C) 2008 Patrik Gornicz, Gornicz_P (at) hotmail (dot) com.
+ *
+ *  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 "Vector2.h"
 #include "mathw.h"
 
@@ -46,7 +63,16 @@ float Vector2::angle() const
 }
 float Vector2::length() const
 {
-    return sqrt(x*x + y*y);
+    return sqrt(sqrLength());
+}
+float Vector2::sqrLength() const
+{
+    return x*x + y*y;
+}
+
+float Vector2::dot(const Vector2& v) const
+{
+    return x*v.x + y*v.y;
 }