source: orxonox.OLD/orxonox/branches/chris/src/camera.cc @ 2105

/* 
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Christian Meyer
   co-programmer: ...
*/

#include "camera.h"
#include "world.h"
#include "world_entity.h"

using namespace std;

/**
   \brief creates a Camera
   
   This standard constructor sets all parameters to zero
*/
Camera::Camera ()
{
        bound = NULL;
        desired_place.r = Vector (0,0,0);
        desired_place.w = Rotation (0,0,0);
        actual_place.r = Vector (0,0,0);
        actual_place.w = Rotation (0,0,0);
}

/**
   \brief default destructor
*/
Camera::~Camera ()
{
}

/**
   \brief time based actualisation of camera parameters
   \param deltaT: The amount of time that has passed in milliseconds
   
   This is called by the World in every time_slice, use it to do fancy time dependant effects (such 
   as smooth camera movement or swaying).
*/
void Camera::time_slice (Uint32 deltaT)
{
        update_desired_place ();
}

/**
  \brief this calculates the location where the track wants the camera to be
   
        This refreshes the placement the camera should have according to the bound entity's position on the track.
*/
void Camera::update_desired_place ()
{
                Orxonox *orx = Orxonox::getInstance();
                Location lookat;
                
                if( bound != NULL)
                {
                        bound->get_lookat (&lookat);
                        orx->get_world()->calc_camera_pos (&lookat, &desired_place);
                }
                else
                {
                        desired_place.r = Vector (0,0,0);
                        desired_place.w = Rotation (0,0,0); 
                }
}

/**
  \brief initialize rendering perspective according to this camera
   
        This is called immediately before the a rendering cycle starts, it sets all global rendering options as
        well as the GL_PROJECTION matrix according to the camera.
*/
void Camera::apply ()
{
        glMatrixMode (GL_PROJECTION);
                // view
                // TO DO: implement options for frustum generation
        glFrustum( -1.0,1.0,-1.0,1.0,1.5,20.0);
        // rotation
  float matrix[16];
  actual_place.w.glmatrix (matrix);
  glLoadMatrixf (matrix);
        // translation
  glTranslatef (actual_place.r.x, actual_place.r.y, actual_place.r.z);
  
  glMatrixMode (GL_MODELVIEW);
  glLoadIdentity ();
}

/**
  \brief set the camera position
  \param plc: The Placement to set the camera to 
        
        This will set the actual and desired placement of the camera to plc
*/
void Camera::jump (Placement* plc = NULL)
{
        if( plc == NULL)
        {
                actual_place = desired_place;
        }
        else
        {
                desired_place = *plc;
                actual_place = *plc;
        }
}

/**
  \brief bind the camera to an entity
  \param entity: The enitity to bind the camera to
        
        This sets the focus of the camera to the given entity. This means that it will use the given WorldEntity's
        Location and get_lookat() to determine the viewpoint the camera will render from.
        Note that you cannot bind a camera to a free entity.
*/
void Camera::bind (WorldEntity* entity)
{
        if( entity != NULL)
        {
                if( entity->isFree ()) printf("Cannot bind camera to free entity");
                else bound = entity;
        } 
}