Surprisingly it is extremely easy implementing in Java.
I did the following 2 test codes:
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
public class TestShape {
private static class DisplayComponent extends JComponent {
private Shape s;
private GeneralPath p = new GeneralPath();
private Area a;
public DisplayComponent() {
this.setSize( 500, 500 );
this.setPreferredSize( new Dimension( 500, 500 ) );
p.append( new Ellipse2D.Double( 50, 50, 50, 50 ), false );
p.append( new Ellipse2D.Double( 75, 75, 50, 50 ), false );
p.append( new Ellipse2D.Double( 150, 150, 50, 50 ), false );
a = new Area( p );
} // end DisplayComponent
public void paintComponent( Graphics g ) {
Graphics2D g2d= (Graphics2D)g;
g2d.setColor( new Color( 255, 0, 0 ) );
g2d.draw( a );
} // end paintComponent
} // end clas
public static void main( String[] args ) {
JFrame frame = new JFrame();
DisplayComponent c = new DisplayComponent();
frame.getContentPane().add( c );
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.pack();
frame.show();
} // end main
} // end class TestShape
The corresponding CSharp test program.
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace TestGraphicsPath
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.PictureBox pictureBox1;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.pictureBox1 = new System.Windows.Forms.PictureBox();
this.SuspendLayout();
//
// pictureBox1
//
this.pictureBox1.Location = new System.Drawing.Point(55, 35);
this.pictureBox1.Name = "pictureBox1";
this.pictureBox1.Size = new System.Drawing.Size(670, 410);
this.pictureBox1.TabIndex = 0;
this.pictureBox1.TabStop = false;
this.pictureBox1.Paint += new
System.Windows.Forms.PaintEventHandler(this.pictur eBox1_Paint);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(832, 553);
this.Controls.Add(this.pictureBox1);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void pictureBox1_Paint(object sender,
System.Windows.Forms.PaintEventArgs e)
{
Graphics g = e.Graphics;
GraphicsPath p1 = new GraphicsPath();
GraphicsPath p2 = new GraphicsPath();
GraphicsPath p3 = new GraphicsPath();
p1.AddEllipse( 50, 50, 50, 50 );
p2.AddEllipse( 75, 75, 50, 50 );
p3.AddEllipse( 150, 150, 50, 50 );
Region r = new Region( p1 );
r.Union( p2 );
r.Union( p3 );
g.FillRegion( Brushes.White, r );
}
}
}
For java, Area is the Region equivalent.
Java , you call call graphics.draw( Area ) and it will draw the outline of
the area.
In CSharp, there isn't graphics.draw( Region ) there is only
graphics.Fill( Region )
I wonder how Java does it.
It does not seem to have much computing effort like the convex hull problem.
Thanks. However, I still need help to implement in CSharp.
Regards,
Altramagnus
"Tom Dacon" <td****@community.nospam> wrote in message
news:uD**************@tk2msftngp13.phx.gbl...
This is an example of a classic graphics problem known as the "convex
hull" problem. Try a search on groups.google.com on that search term, limiting
it to the microsoft .Net groups, and see what you come up with.
Regards,
Tom Dacon
Dacon Software Consulting
"Altramagnus" <al*********@hotmail.com> wrote in message
news:41********@news.starhub.net.sg... I have n number of circles. Some of them might overlap.
I need to draw the outline of all circles but not those overlap areas.
Initially, I am try to use a Region, because a Region object has a Union
function
Creating a GraphicsPath of 1 circle is easy. So I convert each
GraphicsPath to a Region and then Union them.
But I could not get back a GraphicsPath of the Unioned Region.
Does anyone know how to solve my problem?
Thanks.
