source: trunk/vizservers/nanovis/PerfQuery.h @ 884

/*
 * ----------------------------------------------------------------------
 * PerfQuery.h: performance query class
 *              It counts then number of pixels rendered on screen using
 *              OpenGL occlusion query extension
 *
 * ======================================================================
 *  AUTHOR:  Wei Qiao <qiaow@purdue.edu>
 *           Purdue Rendering and Perceptualization Lab (PURPL)
 *
 *  Copyright (c) 2004-2006  Purdue Research Foundation
 *
 *  See the file "license.terms" for information on usage and
 *  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 * ======================================================================
 */

#ifndef _PERFQUERY_H_
#define _PERFQUERY_H_

#include <stdio.h>
#include <GL/glew.h>

#include "define.h"

//check if occlusion query is supported
inline bool check_query_support()
{
    int bitsSupported = -1;
    glGetQueryivARB(GL_SAMPLES_PASSED_ARB, GL_QUERY_COUNTER_BITS_ARB, 
                    &bitsSupported);
    if(bitsSupported == 0) {
        fprintf(stderr, "occlusion query not supported!\n");
        return false;
    } else {
        fprintf(stderr, "Occlusion query with %d bits supported\n", 
                bitsSupported);
        return true;
    }
}

class PerfQuery
{

public:
  NVISid id;
  int pixel;

  PerfQuery();
  ~PerfQuery();

  void enable();        //start counting how many pixels are rendered
  void disable();       //stop counting

  void reset();         //reset pixel count to 0;
  int get_pixel_count();//return current pixel count

};



#endif