tegenerator.h

海量地形数据漫游系统,对于OPENGL开发人员具有一定的参考

#ifndef TE_GENERATOR_H
#define TE_GENERATOR_H

/*****************************************************************************\
 *
 * TeGenerator.h
 *
 * TeGenerator abstract class
 *
 * Author: Martin Havl龛ek (xhavli15 AT stud.fit.vutbr.cz)
 * Contributors:
 *
 * ----------------------------------------------------------------------------
 *
 * THIS SOFTWARE IS NOT COPYRIGHTED
 *
 * This source code is offered for use in the public domain.
 * You may use, modify or distribute it freely.
 *
 * This source code is distributed in the hope that it will be useful but
 * WITHOUT ANY WARRANTY.  ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
 * DISCLAIMED.  This includes but is not limited to warranties of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * If you find the source code useful, authors will kindly welcome
 * if you give them credit and keep their names with their source code.
 *
\*****************************************************************************/

/**
 * TeGenerator abstract class header file.
 *
 * \file TeGenerator.h
 * \author Martin Havl龛ek (martyn AT seznam.cz)
 */

#include "TeHeightMap.h"

/**
 * Abstract class meant to be a parent to all generators.
 *
 * This abstract class defines interface for derived classes.
 *
 * Generators can be used in two different ways with same results.
 * One way is to use generate() method to gain result in single function
 * call. The other way is to call genStep() several times and obtain
 * the result in the near future. The fact that result is ready to use
 * is identified by the TRUE value returned by this method. In case that
 * task is not done yet this function returns FALSE.
 *
 * Typical usage of some generator should look like this:
 * \li Create the generator object (if you didn't do this before). Note, that
 *     TeGenerator class is abstract, so you have to choose from derived
 *     classes.
 * \li Create the TeHeightMap object to store results (or choose the one
 *     already created).
 * \li Call setHMap() method with address of the heightmap as a parameter.
 * \li You can also modify generator parameters to whatever you desire.
 *     The default or the last time used parameters will be used if you
 *     step this point.
 * \li Call generate() method once OR genStep() method several times (task
 *     finish is indicated by returning TRUE).
 * \li The result is in the heightmap object.
 */
class TeGenerator {

protected:

  /** Pointer to the heightmap. */
  TeHeightMap *hmap;
  /** Number of steps required to complete task. */
  int stepNum;
  /** Current step counter. */
  int step;

  // interface for derived classes
  /** Pure virtual function, see derived classes for more information. */
  virtual void updateParams() = 0;

public:

  void reset();
  void setHMap(TeHeightMap *m);

  // interface for derived classes
  /** Pure virtual function, see derived classes for more information. */
  virtual void setDefaults()  = 0;
  /** Pure virtual function, see derived classes for more information. */
  virtual void generate()     = 0;
  /** Pure virtual function, see derived classes for more information. */
  virtual SbBool genStep()    = 0;

};


#endif /* TE_GENERATOR_H */