source: trunk/VUT/work/ogre_changes/RenderSystems/Direct3D9/src/OgreD3D9HardwareOcclusionQuery.cpp @ 88

/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://ogre.sourceforge.net/

Copyright (c) 2000-2005 The OGRE Team
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser 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, or go to
http://www.gnu.org/copyleft/lesser.txt.
-----------------------------------------------------------------------------
*/
#include "OgreD3D9HardwareOcclusionQuery.h"
#include "OgreRenderSystemCapabilities.h"
#include "OgreException.h"

namespace Ogre {

int D3D9HardwareOcclusionQuery::m_Skip = 0;

/**
  * This is a class that is the DirectX9 implementation of 
  * hardware occlusion testing.
  *
  * @author Lee Sandberg
  */

/**
  * Default object constructor
  * 
  */
D3D9HardwareOcclusionQuery::D3D9HardwareOcclusionQuery( IDirect3DDevice9* pD3DDevice ) 
{ 
        m_pD3DDevice = pD3DDevice;
        m_uintPixelCount = 0; 
        m_SkipCounter = 0;
        m_bHWOcclusionSupport = false;

        HRESULT hr = m_pD3DDevice->CreateQuery(D3DQUERYTYPE_OCCLUSION, &m_pD3DQuery);
        if ( hr != D3D_OK ) 
        {
                //OGRE_EXCEPT(hr, "D3D9HardwareOcclusionQuery couldn't create hardware occlusion query object.", 
        //        "D3D9HardwareOcclusionQuery::D3D9HardwareOcclusionQuery");
                m_bHWOcclusionSupport = false;
        }
        else 
        {
                m_bHWOcclusionSupport = true;
        }
}


/**
  * Object destructor
  */
D3D9HardwareOcclusionQuery::~D3D9HardwareOcclusionQuery() 
{ 
        SAFE_RELEASE( m_pD3DQuery ); 
}

//------------------------------------------------------------------
// Occlusion query functions (see base class documentation for this)
//--
void D3D9HardwareOcclusionQuery::beginOcclusionQuery() 
{ 
        if( m_bHWOcclusionSupport )             // Make it fail silently if hardware occlusion isn't supported
        {
                m_pD3DQuery->Issue(D3DISSUE_BEGIN); 
        }
}
//------------------------------------------------------------------
void D3D9HardwareOcclusionQuery::endOcclusionQuery() 
{ 
        if( m_bHWOcclusionSupport )     // Make it fail silently if hardware occlusion isn't supported
        {
                m_pD3DQuery->Issue(D3DISSUE_END); 
        }
}

//------------------------------------------------------------------
// This version of pullOcclusionQuery cases the DX9 API/Driver to flush all commands to the 3D card
// to allow a fast result from the query, but at the cost of poorer batching of API calls to the card.
// Note: OpenGL dosn't use this flag at all so the application running OpenGL won't display any different behaviour.
//--
bool D3D9HardwareOcclusionQuery::pullOcclusionQuery( unsigned int* NumOfFragments, const bool waitForResult ) 
{
        return pullOcclusionQuery(NumOfFragments, waitForResult, HWOCCLUSIONQUERY_FLUSH);
}

//------------------------------------------------------------------
// This version of pullOcclusionQuery cases the DX9 API/Driver to not flush all commands to the 3D card
// to allow a fast result from the query, but the batching of API calls to the card will be normal. 
// But the query wont be processed until the card recives the query in the nexr batch.
// Note: OpenGL dosn't use this flag at all so the application running OpenGL won't display any different behaviour.
//--
bool D3D9HardwareOcclusionQuery::pullOcclusionQuery( unsigned int* NumOfFragments, const bool waitForResult, 
                                                                                                     const HW_OCCLUSIONQUERY flag  ) 
{
        DWORD queryFlag = flag == HWOCCLUSIONQUERY_FLUSH ? D3DGETDATA_FLUSH : 0;
        // TO DO: USE lockOpts= D3D9Mappings::get(options); instead of RS_OCCLUSIONQUERY enum

        return pullOcclusionQuery(NumOfFragments, waitForResult, queryFlag);
}
//------------------------------------------------------------------
bool D3D9HardwareOcclusionQuery::pullOcclusionQuery( unsigned int* NumOfFragments, const bool waitForResult, 
                                                                                                     const DWORD queryFlag ) 
{
        HRESULT hr = S_OK;

        if( m_bHWOcclusionSupport )     // In case hardware occlusion isn't supported
        {       
                do
                {
                        hr = m_pD3DQuery->GetData( NumOfFragments, sizeof( NumOfFragments ), queryFlag );
                }
                while(waitForResult && (hr == S_FALSE));
                
                m_uintPixelCount = *NumOfFragments; 
        }
        else
        {
                m_uintPixelCount = 100000; // every object is visible
        }
        
        return hr == S_OK;
}
} // namespace OGre