Test cases see issue #5 (#259)

Add unit test for:
- Envelope: getCenter() & Merge()
- Envelope2D: clipLine() & sqrDistances()

Author: johansettlin

src/test/java/com/esri/core/geometry/TestEnvelope.java

@@ -21,6 +21,107 @@
 
 public class TestEnvelope
 {
+	@Test
+	/**The function returns the x and y coordinates of the center of the envelope.
+	 * If the envelope is empty the point is set to empty otherwise the point is set to the center of the envelope.
+	 */
+	public void testGetCeneter(){
+		//xmin,ymin,xmax,ymax of envelope
+		Envelope env1 = new Envelope(1,1, 2, 4);
+		Envelope env2 = new Envelope();
+		Point p = new Point();
+		Point p1 = new Point(1,2);
+
+		/**Tests if the point is correctly set to the center of the envelope,   */
+		env1.getCenter(p);
+		assertTrue(p.getX() == 1.5);
+
+		/** Tests if the point is empty because of the envelope is empty */
+		env2.getCenter(p1);
+		assertTrue(p1.isEmpty());
+	}
+	@Test
+	/* Merge takes a Point as input and increas the bouandary of the envelope to contain the point.
+	 *If the point is empty the envelope remains the same or if the envelope is empty the coordinates 
+	 *of the point is assigned to the envelope */
+	public void testMerge(){
+
+		/* To increase the covarege the branch where the envelope is empty can be tested
+		 * And that the envelope and the point is not empty */
+		Envelope env1 = new Envelope(1,1, 2, 4);
+		Envelope env2 = new Envelope(1,1, 2, 4);
+		Envelope env3 = new Envelope(1,1, 2, 4);
+		Point p = new Point(100,4);
+
+		/*This should be false since env1 should change depending on point p */
+		env1.merge(p);
+		assertFalse(env1.equals(env2));
+		
+		/* This assert should be true since the point is empty and therefore env2 should not change */
+		Point p1 = new Point();
+		env2.merge(p1);
+		assertTrue(env2.equals(env3));
+	}
+
+
+	@Test
+	/** TESTEST ENVELOPE2D **
+	 * ClipLine modify a line to be inside a envelope if possible */
+	public void TestClipLine(){
+		
+		//checking if segPrama is 0 and the segment is outside of the clipping window
+		//covers first return
+		Envelope2D env0 = new Envelope2D(1, 1, 4, 4);
+		// Reaches the branch where the delta is 0
+		Point2D p1 = new Point2D(2,2);
+		Point2D p2 = new Point2D(2,2);
+
+		int lineExtension = 0;
+		double[] segParams = {3,4};
+		//reaches the branch where boundaryDistances is not 0
+		double[] boundaryDistances = {2.0, 3.0};
+
+		int a = env0.clipLine(p1, p2, lineExtension, segParams, boundaryDistances);
+		//should be true since the points are inside the envelope
+		assertTrue(a == 4);
+		
+		// Changes p3 to fit the envelop, the line is on the edge of the envelope
+		Envelope2D env1 = new Envelope2D(1, 1, 4, 4);
+		Point2D p3 = new Point2D(1,10);
+		Point2D p4 = new Point2D(1,1);
+
+		int b = env1.clipLine(p3, p4, lineExtension, segParams, boundaryDistances);
+		assertTrue(b == 1);
+		// the second point is outside and therefore changed
+		Envelope2D env2 = new Envelope2D(1, 1, 4, 4);
+		Point2D p5 = new Point2D(2,2);
+		Point2D p6 = new Point2D(1,10);
+
+		int c = env2.clipLine(p5, p6, lineExtension, segParams, boundaryDistances);
+		assertTrue(c == 2);
+
+		//Both points is outside the envelope and therefore no line is possible to clip, and this should return 0
+		Envelope2D env3 = new Envelope2D(1, 1, 4, 4);
+		Point2D p7 = new Point2D(11,10);
+		Point2D p8 = new Point2D(5,5);
+
+		int d = env3.clipLine(p7, p8, lineExtension, segParams, boundaryDistances);
+		assertTrue(d == 0);
+	}
+	
+	@Test
+	public void testSqrDistances(){
+		//the point is on the envelope, which means that the distance is 0
+		Envelope2D env0 = new Envelope2D(1, 1, 4, 4);
+		Point2D p0 = new Point2D(4,4);
+		assertTrue(env0.sqrDistance(p0) == 0.0);
+
+		Envelope2D env1 = new Envelope2D(1, 1, 4, 4);
+		Point2D p1 = new Point2D(1,0);
+		
+		assertTrue(env0.sqrDistance(p1) == 1.0);
+
+	}
 	@Test
 	public void testIntersect() {
 		assertIntersection(new Envelope(0, 0, 5, 5), new Envelope(0, 0, 5, 5), new Envelope(0, 0, 5, 5));