using System;
using System.Runtime.InteropServices;
using System.Reflection;

//Access the Wacom or Genius tablet digitizer through wintab32.dll
//Written by Karl Lilje 2008
//Version 1.0

/*
Usage:
CTablet tablet = new CTablet( this.Handle, this.Width, this.Height);
in your form(this) add the function:

protected override void WndProc(ref Message m)
{
  if ( m.Msg == CTablet.WT_PACKET )
  {
     tablet.Packet( m.LParam, m.WParam );
  }
  base.WndProc (ref m);
}
*/
//now you can query tablet for X, Y, Z, Pressure, Puck ID
//Automatically sets the tablet to move the mouse cursor and click buttons


namespace StereoPaint3
{

[StructLayout(LayoutKind.Explicit)]
	public struct CONTEXT 
			{
				[FieldOffset(0)][MarshalAs( UnmanagedType.ByValTStr, SizeConst=40)]  public string lcName ;
				[FieldOffset(40)] public int	lcOptions;
				[FieldOffset(44)] public int	lcStatus;
				[FieldOffset(48)]public int	lcLocks;
				[FieldOffset(52)]public int	lcMsgBase;
				[FieldOffset(56)]public int	lcDevice;
				[FieldOffset(60)]public int	lcPktRate;
				[FieldOffset(64)]public int	lcPktData;
				[FieldOffset(68)]public int	lcPktMode;
				[FieldOffset(72)]public int	lcMoveMask;
				[FieldOffset(76)]public int	lcBtnDnMask;
				[FieldOffset(80)]public int	lcBtnUpMask;
				[FieldOffset(84)]public int	lcInOrgX;
				[FieldOffset(88)]public int	lcInOrgY;
				[FieldOffset(92)]public int	lcInOrgZ;
				[FieldOffset(96)]public int	lcInExtX;
				[FieldOffset(100)]public int	lcInExtY;
				[FieldOffset(104)]public int	lcInExtZ;
				[FieldOffset(108)]public int	lcOutOrgX;
				[FieldOffset(112)]public int	lcOutOrgY;
				[FieldOffset(116)]public int	lcOutOrgZ;
				[FieldOffset(120)]public int	lcOutExtX;
				[FieldOffset(124)]public int	lcOutExtY;
				[FieldOffset(128)]public int	lcOutExtZ;
				[FieldOffset(132)]public int	lcSensX;
				[FieldOffset(136)]public int	lcSensY;
				[FieldOffset(140)]public int	lcSensZ;
				[FieldOffset(144)]public int	lcSysMode;
				[FieldOffset(148)]public int	lcSysOrgX;
				[FieldOffset(152)]public int	lcSysOrgY;
				[FieldOffset(156)]public int	lcSysExtX;
				[FieldOffset(160)]public int	lcSysExtY;
				[FieldOffset(164)]public int	lcSysSensX;
				[FieldOffset(168)]public int	lcSysSensY;
			} 


	//change this according to your packet required
	public struct structPACKET
	{
		//public int pkStatus;
		//public int pkTime;
		//public int pkSerial;
		public int pkCursor;
		public int pkButtons;
		public int pkX;
		public int pkY;
		public int pkZ;
		public int pkNormalPressure;
		//public int pkTangentPressure;
		//public int pkAzimuth;
		//public int pkAltitude;
		//public int pkTwist;
		//public int pkPitch;
		//public int pkRoll;
		//public int pkYaw;
		//[MarshalAs(UnmanagedType.ByValTStr, SizeConst=1024)] public string extra;
	}
																																									
																																									
	/// <summary>
	/// 
	/// </summary>
	public class CTablet
	{
		[DllImport("wintab32.dll")]
		 static extern uint WTInfo(uint a, uint b, ref CONTEXT c);

		[DllImport("wintab32.dll")]
		static extern uint WTInfo(uint a, uint b, ref int c);

		[DllImport("wintab32.dll")]
		static extern IntPtr WTOpen(IntPtr a, ref CONTEXT b, bool v);

		[DllImport("wintab32.dll")]
		static extern int WTPacket(IntPtr hCtx, int wSerial, ref structPACKET p);

		[DllImport("wintab32.dll")]
		static extern bool WTClose(IntPtr a);



		// Get default context information	
		IntPtr Handle = IntPtr.Zero;
		public bool TabletAvailable = false;
		public int Pressure = 0;
		public int X = 0;
		public int Y = 0;
		public int Z = 0;
		public int Buttons = 0;


		uint WTI_DEFSYSCTX	= 4;
		public const short WT_DEFBASE = 0x7ff0; 
		public const short WT_MAXOFFSET = 0xF;
		public const int WT_PACKET  = WT_DEFBASE + 0;
		public const short CXO_MESSAGES	= 0x0004;
		public const short PK_CURSOR = 0x0020; //the PUCK number
		public const short PK_BUTTONS  = 0x0040;
		public const short PK_X = 0x0080;
		public const short PK_Y = 0x0100;
		public const short PK_Z = 0x0200;
		public const short PK_NORMAL_PRESSURE	= 0x0400;		
		

		//this works in conjunction with the structPACKET structure
		//see the Wintab documentation from Wacom for more information
		public const short PACKETDATA = PK_CURSOR | PK_X | PK_Y | PK_Z | PK_NORMAL_PRESSURE | PK_BUTTONS; 
		

		CONTEXT Context = new CONTEXT();


		//winhandle = handle of the window that will receive tablet messages
		//usually Form1.Handle (this.Handle)
		public CTablet( IntPtr winhandle, int w, int h )
		{
			Console.WriteLine( "Load Wintab.dll..." );
			CONTEXT ret = new CONTEXT();
			Handle=(IntPtr)WTInfo( 0,0, ref ret);


			if ( Handle == IntPtr.Zero ) return ;

			TabletAvailable = true;
			
			WTInfo( WTI_DEFSYSCTX, 0, ref Context );

			//Console.WriteLine( "Tablet loaded, Handle = " + Handle );
			Console.WriteLine( "Tablet: " + Context.lcName );
				
			Context.lcPktData  = PACKETDATA ;
			Context.lcPktMode  = 0;
			Context.lcMoveMask = PACKETDATA;
			Context.lcOptions  |= CXO_MESSAGES; //notify window of packets
			Context.lcOutOrgX  = 0;
			Context.lcOutOrgY  = 0;
			Context.lcOutExtX  = w;
			Context.lcOutExtY  = -h;

			
			Handle = WTOpen( winhandle, ref Context, true );
			Console.WriteLine( "loaded, Handle = " + Handle );			
		}


		//call this from the window that was registered in the constructor
		//from the WndProc override. It decodes the packet message
		public void Packet( IntPtr LPARAM, IntPtr WPARAM)
		{
			structPACKET pkt = new structPACKET();
			WTPacket((IntPtr)LPARAM, (int)WPARAM, ref pkt);

			X = pkt.pkX;
			Y = pkt.pkY;
			Z = pkt.pkZ;
			Buttons = pkt.pkButtons ;
			Pressure = pkt.pkNormalPressure ;
		}

		 ~CTablet( )
		{
			bool b = WTClose( Handle );
			 TabletAvailable = false;
			//Console.WriteLine ( "Closed : " + b  );
		}
	}
}