teengineexplorer.cpp

海量地形数据漫游系统,对于OPENGL开发人员具有一定的参考

/*****************************************************************************\
 *
 * TeObject.cpp
 *
 * TeObject abstract class implementation
 *
 * 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.
 *
\*****************************************************************************/


#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoPerspectiveCamera.h>
#include <Inventor/nodes/SoMaterial.h>
#include <Inventor/nodes/SoFont.h>
#include <Inventor/nodes/SoTranslation.h>
#include <Inventor/nodes/SoRotation.h>
#include <Inventor/events/SoKeyboardEvent.h>
#include <Inventor/events/SoLocation2Event.h>

#include "objects/TeEngineExplorer.h"
#include "TeEngine.h"


//-----------------------------------------------------------------------------
/**
 * Default constructor.
 */
TeEngineExplorer::TeEngineExplorer() : defaultCamDistance(SbVec3f(0.0f, 1.1f, 3.5f))
{
  camDistance = defaultCamDistance;
}


//-----------------------------------------------------------------------------
/**
 * Creates HUD scene graph in engine's HUDRoot.
 */
void TeEngineExplorer::createHUD()
{
  SoSeparator *tmp = engine->getHUDRoot();

  // centered HUD id
  SoFont *font1 = new SoFont;
  font1->name.setValue("Arial");
  font1->size.setValue(20.0);

  SoMaterial *material = new SoMaterial;
  material->diffuseColor.setValue(SbVec3f(1.0f, 1.0f, 1.0f));

  SoTranslation *tr1 = new SoTranslation;
  tr1->translation.setValue(0.0f, 0.37f, 0.0f);

  SoText2 *txt1 = new SoText2;
  txt1->string.setValue("...TerrainEngine Explorer...");
  txt1->justification = SoText2::CENTER;

  tmp->addChild(material);
  tmp->addChild(font1);
  tmp->addChild(tr1);
  tmp->addChild(txt1);

  // controls
  SoFont *font2 = new SoFont;
  font2->name.setValue("Arial");
  font2->size.setValue(15.0);

  SoTranslation *tr2 = new SoTranslation;
  tr2->translation.setValue(0.3f, -0.41f, 0.0f);

  SoText2 *txt2 = new SoText2;
  txt2->string.set1Value(0,"Usage:");
  txt2->string.set1Value(1,"Arrows to change speed");
  txt2->string.set1Value(2,"8, 6, 2, 4 on NumPad,");
  txt2->string.set1Value(3,"  PdUp and PgDown to");
  txt2->string.set1Value(4,"  change camera settings");
  txt2->string.set1Value(5,"ESC to quit");
  txt2->justification = SoText2::LEFT;

  tmp->addChild(font2);
  tmp->addChild(tr2);
  tmp->addChild(txt2);

  // position echo
  SoTranslation *tr4 = new SoTranslation;
  tr4->translation.setValue(-0.75f, -0.24f, 0.0f);

  SoText2 *txt4 = new SoText2;
  posText = txt4;
  txt4->justification = SoText2::LEFT;

  tmp->addChild(tr4);
  tmp->addChild(txt4);

  // speed echo
  SoTranslation *tr5 = new SoTranslation;
  tr5->translation.setValue(0.0f, 0.03f, 0.0f);

  SoText2 *txt5 = new SoText2;
  speedText = txt5;
  txt5->justification = SoText2::LEFT;

  tmp->addChild(tr5);
  tmp->addChild(txt5);

  // FPS echo
  SoTranslation *tr6 = new SoTranslation;
  tr6->translation.setValue(0.0f, 0.06f, 0.0f);

  SoText2 *txt6 = new SoText2;
  fpsText = txt6;
  txt6->justification = SoText2::LEFT;

  tmp->addChild(tr6);
  tmp->addChild(txt6);

  // Tasks in queue echo
  SoTranslation *tr7 = new SoTranslation;
  tr7->translation.setValue(0.0f, 0.06f, 0.0f);

  SoText2 *txt7 = new SoText2;
  tasksInQueueText = txt7;
  txt7->justification = SoText2::LEFT;

  tmp->addChild(tr7);
  tmp->addChild(txt7);

  // Root level echo
  SoTranslation *tr9 = new SoTranslation;
  tr9->translation.setValue(0.0f, 0.06f, 0.0f);

  SoText2 *txt9 = new SoText2;
  rootLevelText = txt9;
  txt9->justification = SoText2::LEFT;

  tmp->addChild(tr9);
  tmp->addChild(txt9);

  // Total number of patches echo
  SoTranslation *tr8 = new SoTranslation;
  tr8->translation.setValue(0.0f, 0.03f, 0.0f);

  SoText2 *txt8 = new SoText2;
  patchNumText = txt8;
  txt8->justification = SoText2::LEFT;

  tmp->addChild(tr8);
  tmp->addChild(txt8);
}


//-----------------------------------------------------------------------------
/**
 * Updates the HUD scene graph.
 *
 * In this function all nodes that reflect actual state should be updated.
 */
void TeEngineExplorer::updateHUD()
{
  char buffer[50];

  sprintf(buffer, "Position: %0.2f, %0.2f", this->getPosition()[0], this->getPosition()[1]);
  posText->string.setValue(buffer);

  sprintf(buffer, "Speed: %0.2f, %0.2f, %0.2f", this->speed.getValue()[0], this->speed.getValue()[1], this->speed.getValue()[2]);
  speedText->string.setValue(buffer);

  sprintf(buffer, "FPS: %0.2f", this->engine->fps);
  fpsText->string.setValue(buffer);

  sprintf(buffer, "Tasks in queue: %d", this->engine->tasksInQueue);
  tasksInQueueText->string.setValue(buffer);

  sprintf(buffer, "DB tree depth: %d", this->engine->getRootLevel());
  rootLevelText->string.setValue(buffer);

  sprintf(buffer, "Generated patches: %d", this->engine->patchesNum);
  patchNumText->string.setValue(buffer);
}


//-----------------------------------------------------------------------------
/**
 * Handles the user interaction.
 *
 * This method defines controls of the object and should represent the
 * physics of the object by correctly adjusted control responses.
 *
 * \param event Event invoked by user interaction.
 */
void TeEngineExplorer::handleEvent(const SoEvent *event)
{
  if (event->isOfType(SoLocation2Event::getClassTypeId())) {
    const SbVec2s &delta = event->getPosition();
    SbRotation rotChange(SbRotation(SbVec3f(0.f,-1.f,0.f), 0.03f*delta[0]) *
                         SbRotation(SbVec3f(-1.f,0.f,0.f), 0.03f*delta[1]));
    this->setOrientation(rotChange * this->getOrientation());

    // rotate the speed vector too
    const SbRotation &orientation = this->getOrientation();
    orientation.inverse().multVec(speed,speed);
    rotChange.multVec(speed,speed);
    orientation.multVec(speed,speed);
    return;
  }

  // basic orientation vectors are present in the matrix:
  // vector pointing forward, to the right, and up.
  SbMatrix m;
  this->getOrientation().getValue(m);
  const float *f = m.operator float*(); // get pointer to matrix floats

  // arrows to change speed vector
  if (SO_KEY_PRESS_EVENT(event, UP_ARROW)) speed += -2.f * SbVec3f(f[8],f[9],f[10]);
  else if (SO_KEY_PRESS_EVENT(event, DOWN_ARROW)) speed += 2.0f * SbVec3f(f[8],f[9],f[10]);
  else if (SO_KEY_PRESS_EVENT(event, LEFT_ARROW)) speed += -2.0f * SbVec3f(f[0],f[1],f[2]);
  else if (SO_KEY_PRESS_EVENT(event, RIGHT_ARROW)) speed += 2.0f * SbVec3f(f[0],f[1],f[2]);

  // pad arrows, PgUp and PgDown to change camera distance
  else if (SO_KEY_PRESS_EVENT(event, PAD_8)) camDistance[1] += 0.05f;
  else if (SO_KEY_PRESS_EVENT(event, PAD_6)) camDistance[0] += 0.05f;
  else if (SO_KEY_PRESS_EVENT(event, PAD_2)) camDistance[1] -= 0.05f;
  else if (SO_KEY_PRESS_EVENT(event, PAD_4)) camDistance[0] -= 0.05f;
  else if (SO_KEY_PRESS_EVENT(event, PAGE_UP)) camDistance[2] += 0.05f;
  else if (SO_KEY_PRESS_EVENT(event, PAGE_DOWN)) camDistance[2] -= 0.05f;

  // pad 5 to default camera distance
  else if (SO_KEY_PRESS_EVENT(event, PAD_5)) camDistance = defaultCamDistance;

  // ESC to quit
  else if (SO_KEY_PRESS_EVENT(event, ESCAPE)) exit(0);
}