From b489968dcc1416a530b9f5289b47962e39ec4158 Mon Sep 17 00:00:00 2001
From: Alexander Sulfrian <alexander@sulfrian.net>
Date: Wed, 21 Mar 2012 21:36:59 +0100
Subject: utils/rectangle: added function to intersect two rectangles

---
 src/utils/rectangle.hpp  | 23 +++++++++++++++++++++++
 test/utils/rectangle.cpp | 26 ++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/src/utils/rectangle.hpp b/src/utils/rectangle.hpp
index fc5d8ac3..e2fddc78 100644
--- a/src/utils/rectangle.hpp
+++ b/src/utils/rectangle.hpp
@@ -104,6 +104,29 @@ namespace usdx
 		{
 			return point2.get_y() - point1.get_y();
 		}
+
+		const Rectangle<T> intersect(const Rectangle<T>& inner) const
+		{
+			Rectangle<T> result(*this);
+
+			if (inner.point1.get_x() > result.point1.get_x()) {
+				result.point1.set_x(inner.point1.get_x());
+			}
+
+			if (inner.point1.get_y() > result.point1.get_y()) {
+				result.point1.set_y(inner.point1.get_y());
+			}
+
+			if (inner.point2.get_x() < result.point2.get_x()) {
+				result.point2.set_x(inner.point2.get_x());
+			}
+
+			if (inner.point2.get_y() < result.point2.get_y()) {
+				result.point2.set_y(inner.point2.get_y());
+			}
+
+			return result;
+		}
 	};
 };
 
diff --git a/test/utils/rectangle.cpp b/test/utils/rectangle.cpp
index f2fe93ea..0cfbece2 100644
--- a/test/utils/rectangle.cpp
+++ b/test/utils/rectangle.cpp
@@ -35,6 +35,8 @@ namespace usdx
 	class RectangleTest : public CppUnit::TestFixture {
 		CPPUNIT_TEST_SUITE(RectangleTest);
 		CPPUNIT_TEST(testInit);
+		CPPUNIT_TEST(testIntersectInner);
+		CPPUNIT_TEST(testIntersectOuter);
  		CPPUNIT_TEST_SUITE_END();
 	private:
 		static log4cpp::Category&  log;
@@ -57,6 +59,30 @@ namespace usdx
 			CPPUNIT_ASSERT(rect.get_width() == 200);
 			CPPUNIT_ASSERT(rect.get_height() == 250);
 		}
+
+		void testIntersectInner()
+		{
+			Rectangle<int> outer(100, 150, 200, 250);
+			Rectangle<int> inner(120, 170, 180, 200);
+			Rectangle<int> intersect = outer.intersect(inner);
+
+			CPPUNIT_ASSERT(intersect.get_point1().get_x() == 120);
+			CPPUNIT_ASSERT(intersect.get_point1().get_y() == 170);
+			CPPUNIT_ASSERT(intersect.get_point2().get_x() == 180);
+			CPPUNIT_ASSERT(intersect.get_point2().get_y() == 200);
+		}
+
+		void testIntersectOuter()
+		{
+			Rectangle<int> outer(120, 170, 180, 200);
+			Rectangle<int> inner(100, 150, 200, 250);
+			Rectangle<int> intersect = outer.intersect(inner);
+
+			CPPUNIT_ASSERT(intersect.get_point1().get_x() == 120);
+			CPPUNIT_ASSERT(intersect.get_point1().get_y() == 170);
+			CPPUNIT_ASSERT(intersect.get_point2().get_x() == 180);
+			CPPUNIT_ASSERT(intersect.get_point2().get_y() == 200);
+		}
 	};
 
 	log4cpp::Category&  RectangleTest::log =
-- 
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