Java Mouse hit test for an unclosed shape, Mouse Position, java.awt.Shape interface, contains method

Mouse hit test for an unclosed shape

2010.8.26

Language

Topics

Mouse hit test for a closed shape
2010.08.26

Mouse hit test for an unclosed shape
2010.08.26

Intersection between two arbitrary curves
2010.09.01

Normal lines to a arbitrary curve
2010.09.01

Common normal lines between two shapes
2016.10.20

Text Editor using the Input Method Framework
2010.12.01

Component Library
2012.09.16

Costom Color Chooser
2012.9.23

Chapter: 1. Source code download, 2. Test results, 3. Test item and method, 4. Comment on the resuls, 5. Test code

1. Source code download

=> CurveHitTest.zip

2. Test resultsreturn=>page top

Figure1 Shapes to be tested

Figure2 Test resuls
Performs the hit test for each gridpoint and display the result by color.
red: on the boundary, gray: not on the boundary

3. Test item and methodreturn=>page top

Basically the mouse cursor is regarded to be hit a curve (including a line and a polyline), if the minimum distance from the mouse cursor to the curve is smaller than the specified value. The calculation of the minimum distance from a point to a curve is performed by the DrawTop Curve2DUtil.getShortestLine (See the Figure 3 below and the video). In the Figure 2, the mouse is regarded to be hit if the minimum distance is smaller than 3 pixels.

			Video: GeometricTest
Figure 3 The nearest points from the mouse cursor to the five curves			Similar test

4. Comment on the resultsreturn=>page top
As you can see in the Figure 2, this test can be applicable to an unclosed curve such as Ex1, Ex5, Ex6 and Ex9.
In the scrolling of the drawing panel (Figure1, 2), the processing time of rewriting (refreshing) the drawing panel takes nearly 2 seconds, so the scrolling seems too slow. However, the rewriting time per one grid point is smaller than 0.1 milli-second. Additionally you can confirm that the processing speed is fast enough for the real time operation by the video (Geometric Test).

5. Test codereturn=>page top

5.1 Classes Overview

Class	Description
CurveHitTest	public class CurveHitTest extends JFrame Creates and assembles the objects of the Jframe, JScrollPane, JViewport and the Panel.
CurveHitTestPanel	public class CurveHitTestPanel extends JPanel Draws several closed shapes and their test results on this object.
TestCase	public class TestCase => TestCase of the RegionHitTest.
TestCurve	public class TestCurve => TestCurve of the RegionHitTest.
Parametric Curves	Segment2D, Curve2D, Rectangle2DE, RoundRectangle2DE, Ellipse2DE, Line2DE, Polyline2DE, CubicCurve2DE, GeneralCurve2DE, FergusonCurve2D
Geometric library	Curve2DUtil.getNormalLines, CurvePT, Matrix, Matrix2D

5.2 Specifications
5.2.1 public class CurveHitTestPanel extends JPanel

Method	Description
createTestCase	public void createTestCase() Creates nine TestCase objects.
getEnlargedBoundingBox	public Rectangle2D getEnlargedBoundingBox(Rectangle2D boundingBox, double wideEx, double heightEx) Parameters: box - The Rectangle2D object. wideEx - The horizontal amount of expanding. heightEx - The vertical amount of expanding. Returns: The Enlarged Rectangle2D object. Processing: Returns the Enlarged Rectangle2D object. Its width is the width of box + 2wideEx andits height width is the height of box + 2heghtEx.
getGridPoints	public Point2D[] getGridPoints(Rectangle2D box) parameters: box - The Rectangle2D object. Returns: The created grid points in the box. Processing: Creates a set of the grid points in the box and returns it. =>The grid point shown in the Figue 2.
ptOnCurve	private int ptOnCurve(Curve2D curve, Point2D point) Parameters: curve - the given curve(including a line and a polyline) point - the point to be tested (mouse cursor position) Returns: 0 - out of the curve 1 - on the curve Processing: Calls the following ptOnSegments method and ptOnBox method.
ptOnSegments	private int ptOnSegments(Curve2D curve, Point2D point, double tol) Parameters: curve - the given curve(including a line and a polyline) point - the point to be tested (mouse cursor position) tol - tolerance Returns: 0 - not on the curve 1 - on the curve Processing: Performs the hit test for each curve segment (Segment2D object). Divides the curve segment and covers each piece by a box and judges the hit test by the ptOnBox method.
ptOnBox	private int ptOnBox(Rectangle2D box, Point2D point, double tol) Parameters: box - a rectangle point - the point to be tested (mouse cursor position) tol - tolerance Returns: 0 - not on the box 1 - on the box Processing: Judges whether the point is contained in the larger box which expands the box outside by tol. In other words, returns 1, if the point is contained in the expanded box, otherwise returns 0.
paint	public void paint(Graphics g) Draws the shapes in the TestCase objects on this panel by the paintShape method, and draws their test results by the paintOnCurve method.
paintShape	public void paintShape(Graphics g) Draws the shapes in the TestCase objects on this panel (Figure1).
paintOnCurve	public void paintOnCurve(Graphics g) Draws the test resuls on this panel (Figure2).