teobject.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/SoDB.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoTranslation.h>
#include <Inventor/nodes/SoRotation.h>
#include <Inventor/nodes/SoPerspectiveCamera.h>
#include <Inventor/nodes/SoMaterial.h>
#include <Inventor/nodes/SoFont.h>
#include <Inventor/nodes/SoText2.h>
#include <Inventor/events/SoKeyboardEvent.h>

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


const SbVec3f& TeObject::getPosition() const
{
  return translation->translation.getValue();
}


void TeObject::setPosition(const SbVec3f &pos)
{
  translation->translation.setValue(pos);
}


void TeObject::setPosition(const float x, const float y, const float z)
{
  translation->translation.setValue(x,y,z);
}


const SbRotation& TeObject::getOrientation() const
{
  return rotation->rotation.getValue();
}


void TeObject::setOrientation(const SbRotation &orient)
{
  rotation->rotation.setValue(orient);
}


void TeObject::setOrientation(const float q0, const float q1, const float q2, const float q3)
{
  rotation->rotation.setValue(q0,q1,q2,q3);
}


//-----------------------------------------------------------------------------
/**
 * Default constructor.
 *
 * Sets TeObject::initialized to FALSE, and zeroes TeObject::position and
 * TeObject::speed.
 */
TeObject::TeObject() : engine(NULL),
                       initialized(FALSE),
                       root(NULL),
                       translation(NULL),
                       rotation(NULL),
                       camDistance(SbVec3f(0.0f, 0.0f, 0.0f)),
                       speed(SbVec3f(0.0f, 0.0f, 0.0f))
{
  createHiddenScene();
}


//-----------------------------------------------------------------------------
/**
 * Destructor.
 *
 * Releases internal scene and removes self from engine's object list.
 */
TeObject::~TeObject()
{
  releaseHiddenScene();
  engine->removeObject(this);
}


//-----------------------------------------------------------------------------
/**
 * Creates internal hidden scene that represents the object.
 *
 * \sa releaseHiddenScene()
 */
void TeObject::createHiddenScene()
{
  root = new SoSeparator;
  root->ref();

  translation = new SoTranslation;
  translation->translation.setValue( SbVec3f(0.0f, 0.0f, 0.0f) );
  root->addChild(translation);

  rotation = new SoRotation;
  rotation->rotation.setValue( SbRotation( SbVec3f(1.0f, 0.0f, 0.0f), 90.0f * (float)M_PI / 180.0f ));
  root->addChild(rotation);

  model = NULL;
  collisionModel = NULL;
}


//-----------------------------------------------------------------------------
/**
 * Destroys internal hidden scene that represents the object.
 *
 * \sa createHiddenScene()
 */
void TeObject::releaseHiddenScene()
{
  root->unref();
  if (collisionModel)
    collisionModel->unref();
}


//-----------------------------------------------------------------------------
/**
 * Creates HUD scene graph in engine's HUDRoot.
 */
void TeObject::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("...TeObject...");
  txt1->justification = SoText2::CENTER;

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


//-----------------------------------------------------------------------------
/**
 * Updates the HUD scene graph.
 *
 * This method is empty in this base class, because HUD is static.
 */
void TeObject::updateHUD() {}


//-----------------------------------------------------------------------------
/**
 * Updates camera position.
 *
 * The camera is positioned at the object's coordinates.
 */
void TeObject::updateCamera()
{
  SbVec3f cameraShift;
  getOrientation().multVec(camDistance, cameraShift);

  (engine->getSceneCamera())->position.setValue(getPosition() + cameraShift);
  (engine->getSceneCamera())->orientation.setValue(getOrientation());
}


//-----------------------------------------------------------------------------
/**
 * Time tick function.
 *
 * It moves the object according to the speed vector and the time elapsed
 * since last call, updates scene camera and calls updateHUD() method.
 *
 * \param delta Time elapsed since last call.
 */
void TeObject::timeTick(const SbTime delta)
{
  // update position
  setPosition(getPosition() + speed * (float)delta.getValue());

  if (engine->getActiveObject() == this) {
    this->updateCamera(); // update camera position
    this->updateHUD();    // update HUD
  }
}


//-----------------------------------------------------------------------------
/**
 * Private attribute accessor.
 *
 * \return Scene for object model rendering.
 *
 * \sa root
 */
SoSeparator *TeObject::getSceneGraph()
{
  return root;
}


//-----------------------------------------------------------------------------
/**
 * Private attribute accessor.
 *
 * \return Translation node of the internal scene.
 *
 * \sa translation
 */
SoTranslation *TeObject::getTranslation()
{
  return translation;
}


//-----------------------------------------------------------------------------
/**
 * Private attribute accessor.
 *
 * \return Model for object rendering.
 *
 * \sa model
 */
SoNode *TeObject::getModel()
{
  return model;
}


//-----------------------------------------------------------------------------
/**
 * Private attribute accessor.
 *
 * \return Model for collision detection.
 *
 * \sa collisionModel
 */
SoNode *TeObject::getCollisionModel()
{
  return collisionModel;
}


//-----------------------------------------------------------------------------
/**
 * Sets selected model attribude.
 *
 * \param model Pointer to the node that contains the model scene.
 * \param which Model selector.
 */
void TeObject::setModel(SoNode *model, MODEL_SET which)
{
  if ((which & RENDER) != 0) {
    if (this->model)
      root->removeChild(this->model);

    this->model = model;

    if (model)
      root->addChild(model);
  }

  if ((which & COLLISION) != 0) {
    if (this->collisionModel)
      this->collisionModel->unref();

    this->collisionModel = model;

    if (this->collisionModel)
      this->collisionModel->ref();
  }
}


//-----------------------------------------------------------------------------
/**
 * Sets selected model attribude.
 *
 * \param filename Name of file that contains the model scene.
 * \param which Model selector.
 * \return TRUE if the file exists and the model was loaded.
 */
SbBool TeObject::setModel(const char *filename, MODEL_SET which)
{
  if (!which)
    return TRUE;

  SoInput in;
  if (!in.openFile(filename))
    return FALSE;

  SoSeparator *model = SoDB::readAll(&in);
  model->ref();

  setModel(model, which);
  model->unref();

  return TRUE;
}


//-----------------------------------------------------------------------------
/**
 * Handles the user interaction.
 *
 * This method is almost empty in this base class. It only provides chance to
 * quit the application.
 *
 * \param event Event invoked by user interaction.
 */
void TeObject::handleEvent(const SoEvent *event)
{
  if (SO_KEY_PRESS_EVENT(event, ESCAPE)) exit(0);
};