Computer Vision Applications with C# - Part II

using System;
using System.Windows.Forms;
using System.Drawing;
using System.Drawing.Imaging;

using ImageProcessor;

namespace UIGraphic
{
	/// <summary>
	/// Summary description for Graphics.
	/// </summary>
	public class Drawer
	{
        public static void DrawWindow(PictureBox picBox, Window roi, Color color)
		{
			Graphics g = picBox.CreateGraphics();			
			Pen p = new Pen(color, 2);			
			ControlPaint.DrawReversibleFrame(picBox.RectangleToScreen(roi.RegionOfInterest), color, FrameStyle.Dashed);
			g.DrawRectangle(p, roi.RegionOfInterest);
			g.Dispose();
		}

        public static Bitmap DrawMoment(Bitmap bitmap, Moment moment, Point centre)
        {
            Graphics g = Graphics.FromImage(bitmap);
            Pen p = new Pen(Color.Red, 2);
            Pen pw = new Pen(Color.Blue, 2);

            int l = moment.Length;
            int w = moment.Width;

            //ROLL -90 to +90
            float rollAngleDeg = moment.ToDegrees(moment.RollRadians);
            float rollAngleRad = moment.RollRadians;

            if (rollAngleDeg < 0) //4th quadrant
            {
                rollAngleDeg = -1 * rollAngleDeg;
                g.DrawLine(p, centre, new Point(centre.X + (int)Math.Ceiling(l * Math.Cos(moment.ToRadians(rollAngleDeg))),
                    centre.Y + (int)Math.Ceiling(l * Math.Sin(moment.ToRadians(rollAngleDeg))))); //centroid to top with l
                g.DrawLine(p, centre, new Point(centre.X - (int)Math.Ceiling(l * Math.Cos(moment.ToRadians(rollAngleDeg))),
                    centre.Y - (int)Math.Ceiling(l * Math.Sin(moment.ToRadians(rollAngleDeg))))); //centroid to bottom with l
                g.DrawLine(pw, centre,
                    new Point(centre.X - (int)Math.Ceiling(w * Math.Cos(moment.ToRadians(90.0f - rollAngleDeg))),
                    centre.Y + (int)Math.Ceiling(w * Math.Sin(moment.ToRadians(90.0f - rollAngleDeg))))); //centroid to right with w
                g.DrawLine(pw, centre,
                    new Point(centre.X + (int)Math.Ceiling(w * Math.Cos(moment.ToRadians(90.0f - rollAngleDeg))),
                    centre.Y - (int)Math.Ceiling(w * Math.Sin(moment.ToRadians(90.0f - rollAngleDeg))))); //centroid to left with w            
            }
            else //1st quadrant
            {
                g.DrawLine(p, centre, new Point(centre.X + (int)Math.Ceiling(l * Math.Cos(rollAngleRad)),
                    centre.Y - (int)Math.Ceiling(l * Math.Sin(rollAngleRad)))); //centroid to top with l
                g.DrawLine(p, centre, new Point(centre.X - (int)Math.Ceiling(l * Math.Cos(rollAngleRad)),
                    centre.Y + (int)Math.Ceiling(l * Math.Sin(rollAngleRad)))); //centroid to bottom with l
                g.DrawLine(pw, centre,
                    new Point(centre.X + (int)Math.Ceiling(w * Math.Cos(moment.ToRadians(90.0f - rollAngleDeg))),
                    centre.Y + (int)Math.Ceiling(w * Math.Sin(moment.ToRadians(90.0f - rollAngleDeg))))); //centroid to right with w
                g.DrawLine(pw, centre,
                    new Point(centre.X - (int)Math.Ceiling(w * Math.Cos(moment.ToRadians(90.0f - rollAngleDeg))),
                    centre.Y - (int)Math.Ceiling(w * Math.Sin(moment.ToRadians(90.0f - rollAngleDeg))))); //centroid to left with w
            }

            g.Dispose();

            return bitmap;
        }

	}
}