What would be the best way to simulate Radar in C#?

Question

I have a Picture box inside a Groupbox in my form with the Picture of a radar set as the background picture. My intention is to dynamically load tiny Jpeg images within the

Answer 1

Click here to run a sample application that demonstrates the basics of how to do radar (or one way, at least). Note: this application does not do double-buffering or transparency of the tiny image.

Source code for the project is here.

Update code:

public partial class Form1 : Form
{
    private Bitmap _canvas;
    private float _sweepStartAngle = -90;
    private float _sweepAngle = 15;
    private SolidBrush _sweepBrush = new SolidBrush(Color.Red);
    private Rectangle _sweepRect;
    private Timer _sweepTimer = new Timer();
    private Bitmap _submarine;
    private Point _submarinePosition = new Point(0, 0);
    private Random rnd = new Random();

    public Form1()
    {
        InitializeComponent();

        _canvas = new Bitmap(pbScope.Width, pbScope.Height);
        pbScope.Image = _canvas;
        _sweepRect = new Rectangle(0, 0, pbScope.Width, pbScope.Height);

        _submarine = (Bitmap)pbSubmarine.Image;

        RedrawScope();

        _sweepTimer.Interval = 100;
        _sweepTimer.Tick += new EventHandler(_sweepTimer_Tick);
        _sweepTimer.Start();
    }

    void _sweepTimer_Tick(object sender, EventArgs e)
    {
        _sweepStartAngle += _sweepAngle;
        RedrawScope();
    }

    private void RedrawScope()
    {
        using (Graphics g = Graphics.FromImage(_canvas))
        {
            // draw the background
            g.DrawImage(pbBackground.Image, 0, 0);

            // draw the "sweep"
            GraphicsPath piepath = new GraphicsPath();
            piepath.AddPie(_sweepRect, _sweepStartAngle, _sweepAngle);
            g.FillPath(_sweepBrush, piepath);
            //g.FillPie(_sweepBrush, _sweepRect, _sweepStartAngle, _sweepAngle);

            // move the submarine and draw it
            _submarinePosition.X += rnd.Next(3);
            _submarinePosition.Y += rnd.Next(3);
            // check if submarine intersects with piepath
            Rectangle rect = new Rectangle(_submarinePosition, _submarine.Size);
            Region region = new Region(piepath);
            region.Intersect(rect);
            if (!region.IsEmpty(g))
            {
                g.DrawImage(_submarine, _submarinePosition);
            }
        }
        pbScope.Image = _canvas;
    }

    private void Form1_FormClosing(object sender, FormClosingEventArgs e)
    {
        _sweepTimer.Stop();
        _sweepTimer.Dispose();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        //GraphicsPath piepath = new GraphicsPath();
        //piepath.AddPie(

    }

}

   private void InitializeComponent()
    {
        System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1));
        this.pbScope = new System.Windows.Forms.PictureBox();
        this.pbBackground = new System.Windows.Forms.PictureBox();
        this.pbSubmarine = new System.Windows.Forms.PictureBox();
        ((System.ComponentModel.ISupportInitialize)(this.pbScope)).BeginInit();
        ((System.ComponentModel.ISupportInitialize)(this.pbBackground)).BeginInit();
        ((System.ComponentModel.ISupportInitialize)(this.pbSubmarine)).BeginInit();
        this.SuspendLayout();
        // 
        // pbScope
        // 
        this.pbScope.Location = new System.Drawing.Point(12, 12);
        this.pbScope.Name = "pbScope";
        this.pbScope.Size = new System.Drawing.Size(300, 300);
        this.pbScope.TabIndex = 0;
        this.pbScope.TabStop = false;
        // 
        // pbBackground
        // 
        this.pbBackground.Image = ((System.Drawing.Image)(resources.GetObject("pbBackground.Image")));
        this.pbBackground.Location = new System.Drawing.Point(341, 12);
        this.pbBackground.Name = "pbBackground";
        this.pbBackground.Size = new System.Drawing.Size(300, 300);
        this.pbBackground.TabIndex = 1;
        this.pbBackground.TabStop = false;
        this.pbBackground.Visible = false;
        // 
        // pbSubmarine
        // 
        this.pbSubmarine.Image = ((System.Drawing.Image)(resources.GetObject("pbSubmarine.Image")));
        this.pbSubmarine.Location = new System.Drawing.Point(658, 45);
        this.pbSubmarine.Name = "pbSubmarine";
        this.pbSubmarine.Size = new System.Drawing.Size(48, 48);
        this.pbSubmarine.TabIndex = 2;
        this.pbSubmarine.TabStop = false;
        this.pbSubmarine.Visible = false;
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(326, 328);
        this.Controls.Add(this.pbSubmarine);
        this.Controls.Add(this.pbBackground);
        this.Controls.Add(this.pbScope);
        this.Name = "Form1";
        this.Text = "Radar";
        this.Load += new System.EventHandler(this.Form1_Load);
        this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.Form1_FormClosing);
        ((System.ComponentModel.ISupportInitialize)(this.pbScope)).EndInit();
        ((System.ComponentModel.ISupportInitialize)(this.pbBackground)).EndInit();
        ((System.ComponentModel.ISupportInitialize)(this.pbSubmarine)).EndInit();
        this.ResumeLayout(false);

    }