//#include "glInterface.h"
#include "OcclusionQuery.h"
#include <iostream>
//#include <GL/gl.h>
//#include <QtOpenGL>
#include <glInterface.h>


using namespace std;

namespace GtpVisibilityPreprocessor {

bool OcclusionQuery::sUseArbQueries = true;


OcclusionQuery::OcclusionQuery()
{
	GLuint id;

	if (sUseArbQueries)
	{
		glGenQueriesARB(1, &id);
	}
	else
	{		
		glGenOcclusionQueriesNV(1, &id);
	}
}

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


OcclusionQuery::~OcclusionQuery()
{
	if (sUseArbQueries)
	{
		glDeleteQueriesARB(1, &mId);
	}
	else
	{
		glDeleteOcclusionQueriesNV(1, &mId);
	}
	
}
//-----------------------------------------------------------------------
void OcclusionQuery::BeginQuery()
{
	if (sUseArbQueries)
	{
		glBeginQueryARB(GL_SAMPLES_PASSED_ARB, mId);
	}
	else
	{
		glBeginOcclusionQueryNV(mId);
	}
}
//-----------------------------------------------------------------------
void OcclusionQuery::EndQuery()
{
	if (sUseArbQueries)
	{
		glEndQueryARB(GL_SAMPLES_PASSED_ARB);
	}
	else
	{
		glEndOcclusionQueryNV();	
	}
}


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

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

	if (sUseArbQueries)
	{
		//GLint available;
		glGetQueryObjectuivARB(mId,
							   GL_QUERY_RESULT_AVAILABLE_ARB,
                               &available);
		return available == GL_TRUE;
	}
	else
	{
		
		glGetOcclusionQueryuivNV(mId, GL_PIXEL_COUNT_AVAILABLE_NV, &available);

		return available == GL_TRUE;
	}

}


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

	if (sUseArbQueries)
	{
//		GLint sampleCount;
		glGetQueryObjectuivARB(mId, GL_QUERY_RESULT_ARB, &sampleCount);
		return sampleCount;
	}
	else
	{	

		glGetOcclusionQueryuivNV(mId, GL_PIXEL_COUNT_NV, &sampleCount);
		return sampleCount;
	}	
}


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


		if (sUseArbQueries)
		{
			glGenQueriesARB(n, (unsigned int *)newQueries);
		}
		else
		{
			glGenOcclusionQueriesNV(n, (unsigned int *)newQueries);
		}

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

		delete [] newQueries;
	}
}
} // namespace