#include "OcclusionQuery.h"
#include <iostream>


#ifdef _WIN32
#include <glInterface.h>
#else
#include <GL/gl.h>
#include <GL/glu.h>
//#include <GL/glxext.h>
#include <SDL/SDL_opengl.h>
#endif

//#ifdef _WIN32
// This Macro does not compile under LINUX
//#define _ARBGL
//#endif


using namespace std;

namespace GtpVisibilityPreprocessor 
{

const static bool sUseArbQueries = true;


OcclusionQuery::OcclusionQuery()
{
	GLuint id;
	
	if (sUseArbQueries)
	{
#ifdef _WIN32
		// VH
		glGenQueriesARB(1, &id);
#endif
	}
	else
	{		
#ifdef _WIN32
		// VH
		glGenOcclusionQueriesNV(1, &id);
#endif
	}
}


OcclusionQuery::OcclusionQuery(const unsigned int idx):
mId(idx)
{
}


OcclusionQuery::~OcclusionQuery()
{
	if (sUseArbQueries)
	{
#ifdef _WIN32
		// VH
		glDeleteQueriesARB(1, &mId);
#endif
	}
	else
	{
#ifdef _WIN32
		// VH
		glDeleteOcclusionQueriesNV(1, &mId);
#endif
	}
	
}


void OcclusionQuery::BeginQuery()
{
	if (sUseArbQueries)
	{
#ifdef _WIN32
		// VH
		//cout << "issuing arb query" << endl;
		glBeginQueryARB(GL_SAMPLES_PASSED_ARB, mId);
#endif
	}
	else
	{
#ifdef _WIN32
		// VH
		cout << "issuing nv query" << endl;
		glBeginOcclusionQueryNV(mId);
#endif
	}
}


void OcclusionQuery::EndQuery()
{
	if (sUseArbQueries)
	{
#ifdef _WIN32
		// VH
		//cout << "ending query" << endl;
		glEndQueryARB(GL_SAMPLES_PASSED_ARB);
#endif
	}
	else
	{
#ifdef _WIN32
		// VH
		glEndOcclusionQueryNV();	
#endif
	}
}


unsigned int OcclusionQuery::GetQueryId() const
{
	return mId;
}


bool OcclusionQuery::ResultAvailable() const
{
	GLuint available = GL_TRUE;

	if (sUseArbQueries)
	{
#ifdef _WIN32
		// VH
		glGetQueryObjectuivARB(mId, GL_QUERY_RESULT_AVAILABLE_ARB, &available);
#endif		
	}
	else
	{
#ifdef _WIN32
		// VH
		glGetOcclusionQueryuivNV(mId, GL_PIXEL_COUNT_AVAILABLE_NV, &available);
#endif
	}

	return available == GL_TRUE;
}


unsigned int OcclusionQuery::GetQueryResult() const
{
	GLuint sampleCount = 1;

	if (sUseArbQueries)
	{
#ifdef _WIN32
		// VH
		glGetQueryObjectuivARB(mId, GL_QUERY_RESULT_ARB, &sampleCount);
#endif
	}
	else
	{	
#ifdef _WIN32
		// VH
		glGetOcclusionQueryuivNV(mId, GL_PIXEL_COUNT_NV, &sampleCount);
#endif		
	}	
	
	return sampleCount;
}


void OcclusionQuery::GenQueries(std::vector<OcclusionQuery * > &queries, 
								int numQueries)
{
	if ((int)queries.size() < numQueries)
	{
		const int n = numQueries - (int)queries.size();
		unsigned int *newQueries = new unsigned int[n];


		if (sUseArbQueries)
		{
#ifdef _WIN32
			// VH
			glGenQueriesARB(n, (unsigned int *)newQueries);
			//cout << "creating " << n << " arb queries" <<  endl;
#endif
		}
		else
		{
#ifdef _WIN32
			// VH		  
			glGenOcclusionQueriesNV(n, (unsigned int *)newQueries);
			//cout << "creating " << n << " nv queries" <<  endl;
#endif		  
		}

		for (int i = 0; i < n; ++ i)
		{
			queries.push_back(new OcclusionQuery(newQueries[i]));
			//cout << "q: " << i << " id: " << newQueries[i] << endl;
		}

		delete [] newQueries;
	}
}


} // namespace