"Paint.exe" in CsGL

using System;
using System.Drawing;
using System.Diagnostics;
using CsGL.OpenGL;

namespace _2D_draw
{
	/// <summary>
	/// Base class for the free draw (points) , the line draw object, and others as we add them
	/// </summary>
	public  class DrawingObject
	{
		protected int color;
		protected int Height;		// height of the view where we are plotting
		protected int TopWidth;	// thickness of the top of the form (menu bar, etc)
		protected int CursorMid;	// off set to the crosshair cursor mid point
		protected string strType;	// hold the "Pencil", "Line" type
		public uint ID;			// for hit testing

		public  DrawingObject()
		{
			Height = 100;		// just so it will never be undefined
			TopWidth = 20;
			CursorMid = 4;			
			ID = 0;
		}

		/// <summary>
		/// we need the width of the top bar on the form, and we need the height of
		/// the cursor
		/// </summary>
		/// <param name="h">height</param>
		/// <param name="t">top width</param>
		/// <param name="c">cursor height</param>
		public   void SetUp( int h , int t , int c , uint id)
		{
			Height = h;		// height of the view where we are plotting
			TopWidth = t;	// thickness of the top of the form (menu bar, etc)
			CursorMid = c;	// off set to the crosshair cursor mid point
			ID = id;		// for hit testing
		}

		// put the coord transform we need to relate the cursor position to the dot position
		protected Point transform(int iX , int iY)
		{
			//Trace.WriteLine("DrawingObjectBase.transform: " + iX.ToString() +"  "+ iY.ToString()); 

			Point p = new Point();
			p.X = iX;
			p.Y = (Height - iY) - TopWidth + CursorMid ; // transform window coor to open gl coord
			return p;
		}

		public virtual void Draw( uint mode , uint highlight)
		{
		}

		public virtual void HandleMouseDown(System.Windows.Forms.MouseEventArgs e){}

		public virtual void HandleMouseUp(System.Windows.Forms.MouseEventArgs e){}

		public virtual void HandleMouseMove(System.Windows.Forms.MouseEventArgs e){}

		protected void DrawLine( Point pStart , Point pEnd )
		{
			if ( pStart == pEnd ) return;
			GL.glBegin( GL.GL_LINES );
			GL.glVertex2i( pStart.X , pStart.Y );
			GL.glVertex2i( pEnd.X , pEnd.Y );
			GL.glEnd();
		}


		protected void DrawDot( Point p )
		{
			DrawDot( p.X , p.Y );
		}

		protected void DrawDot( int ix , int iy )
		{
			GL.glBegin( GL.GL_POINTS );
			GL.glVertex2i( ix , iy );
			GL.glEnd();
		}


		#region PrintError
		// **************************************************
		// pretty print the error
		// http://www.opengl.org/documentation/blue_book_1.0/book/ch05.html#id5488181
		public void PrintGLError( uint err, String from)
		{
			if ( err == GL.GL_NO_ERROR ) return;	// don't print
			if ( from != "" ) System.Console.WriteLine("GL Error: " + from);
			PrintGLError( err);
		}

		void PrintGLError( uint err)
		{
			String pretty = "";

			switch ( err )
			{
				case GL.GL_NO_ERROR:
					pretty = "GL_NO_ERROR ";
					pretty = pretty + "No error has been recorded. The value of this symbolic constant is guaranteed to be zero. ";
					break;
				case GL.GL_INVALID_ENUM:
					pretty = "GL_INVALID_ENUM ";
					pretty = pretty + "An unacceptable value is specified for an enumerated argument. The offending command is ignored, having no side effect other than to set the error flag ";
					break;
				case GL.GL_INVALID_VALUE:
					pretty = "GL_INVALID_VALUE ";
					pretty = pretty + "A numeric argument is out of range. The offending command is ignored, having no side effect other than to set the error flag.  ";
					break;
				case GL.GL_INVALID_OPERATION:
					pretty = "GL_INVALID_OPERATION ";
					pretty = pretty + "The specified operation is not allowed in the current state. The offending command is ignored, having no side effect other than to set the error flag.  ";
					break;
				case GL.GL_STACK_OVERFLOW:
					pretty = "GL_STACK_OVERFLOW ";
					pretty = pretty + "This command would cause a stack overflow. The offending command is ignored, having no side effect other than to set the error flag.  ";
					break;
				case GL.GL_STACK_UNDERFLOW:
					pretty = "GL_STACK_UNDERFLOW ";
					pretty = pretty + "This command would cause a stack underflow. The offending command is ignored, having no side effect other than to set the error flag.  ";
					break;
				case GL.GL_OUT_OF_MEMORY:
					pretty = "GL_OUT_OF_MEMORY ";
					pretty = pretty + "There is not enough memory left to execute the command. The state of the GL is undefined, except for the state of the error flags, after this error is recorded.  ";
					break;
			}
			System.Console.WriteLine("GL Error: " + pretty);
		}
		#endregion PrintError


		public string type
		{
			get
			{
				return strType;
			}
		}

		public string comment
		{
			get
			{
				return null;
			}
			set
			{
			}
		}


	}
}