//------------------------------------------------------------------------
//
//  VisDataRender.h
//  
//  The CVisDataRender wraps around a thread that will load data and 
//  render it.  Some type of Data Loader (CVisDataLoader) is passed in.
//  It is called to load the data into the passed buffers.  Once that has
//  completed, the Render method on the passed Vis is called to render.  
//  
//  By using this, instead of, say, WM_TIMER, you can get pretty good 
//  performance.  The next improvement will be to double-thread it.  By 
//  allowing the Data Loader to take any amount of time to load the data,
//  it can effectly kill the perfomance.  By adding a Data load thread,
//  in addition to a render thread, complete control of how often the 
//  Render gets called can be done.
//
//
//   -------------------------------------------------------------------
//  * COPYRIGHT 2001, Greg Ratajik and Ratajik Software                 *
//  * All rights Reserved                                               *
//   -------------------------------------------------------------------
//
//  This program is free software; you can redistribute it and/or
//  modify it under the terms of the GNU General Public License
//  as published by the Free Software Foundation; either version 2
//  of the License, or (at your option) any later version.
//  
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//  
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
//  More information about this program can be found at:
//          http://www.ratajik.com/VisInterface

//                            C H A N G E    L O G                           
// =====================================================================
// Change ID    Date        Programmer  Description                                      
// ============ =========   =========== ================================
//              02-05-01    Ratajik     Initial Development
//------------------------------------------------------------------------
#pragma once

#include "VisInterface.h"
#include "VisDataLoader.h"
#include <afxmt.h>

UINT WorkerThread(LPVOID lpParam);  // The thread that actually renders.

//------------------------------------------------------------------------
//                                                                           
//       Class: CVisRender
//                                                                           
// Description: This little class just starts up and maintaines the worker
//              thread.
//
//     Methods
//          of  
//    Interest: CVisDataRender ()
//                 - Only ctor
//
//              StartRendering()
//                 - Start the thread, if it isn't started already.
//
//              StopRendering()
//                 - Stop the thread, if it is running (via a sem).  This 
//                   call will not return until the thread has actually
//                   stopped.
//          
//                            C H A N G E    L O G                           
// ===================================================================
// Change ID    Date        Programmer  Description                                      
// ============ =========   =========== ================================
//              02-21-01    Ratajik     Initial Development                            
//_________________________________________________________________________
class CVisDataRender
{
public:
    friend UINT WorkerThread(LPVOID);    

    CVisDataRender(CWnd *pParentWnd, CVisInterface *pInterface, CVisDataLoader *pLoader);

    bool StartRendering( void );
    bool StopRendering ( void );

protected:

private:
    CWinThread      *m_pThread;     // The Created Thread
    CWnd            *m_pParentWnd;  // Our Parent Wnd (not used)
    CVisInterface   *m_pInterface;  // The Vis to use (must already be selected())
    CVisDataLoader  *m_pLoader;     // The Data loader to use
    CSemaphore       m_semStop;     // The control Semaphore
    CSingleLock      m_SingleLock;  // Locker for the Sem.
};