//****************************************************************************

//! \file engine.hpp
//! \date 12-02-2003

//! \class GLView
//! \brief The engine of the Weird Demo

//! \struct Tcoord
//! \brief the koordinates phasespace

//! \struct TGLObject
//! \brief derifed struct designed to contain GL Object lists

//! \struct TGLLight
//! \brief derived struct designed to contain GL Lights
//****************************************************************************

//     This file is part of the Weird Demo.
//
//     The Weird Demo 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 of the License, or
//     (at your option) any later version.
//
//     The Weird Demo is distributed in the hope that it will be useful,
//     but WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//     GNU General Public License for more details.
//
//     You should have received a copy of the GNU General Public License
//     along with DataView; if not, write to the Free Software
//     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

//****************************************************************************

#ifndef ENGINE_HPP
#define ENGINE_HPP

#include <qgl.h>
#include <qcursor.h>
#include <qimage.h>

#include <iostream>
#include <cmath>

#include <vector>
#include <map>

static const double P2 = 18/M_PI;
static const double P3 = 180/M_PI;

using namespace std;

//***************************************************************************
struct Tcoord
//----------------------------------------------------------------------------
//! base class for all object characterisation structs; containing coordinates,
//! the speed vector, the eulerian angles und the rotation vector
//! used as Camera coordinate container
//! \todo get rid of the double coordinate representation and introduce vectors
//***************************************************************************
{
	double x;//!< the position x coordinate
	double y;//!< the position y coordinate
	double z;//!< the position z coordinate
	double vx;//!< the position x speed coordinate
	double vy;//!< the position y speed coordinate
	double vz;//!< the position z speed coordinate
	double ax;//!< the position euler angle around x axis
	double ay;//!< the position euler angle around y axis
	double az;//!< the position euler angle around z axis
	double vax;//!< the position rotation speed around x axis
	double vay;//!< the position rotation speed around y axis
	double vaz;//!< the position rotation speed around z axis

	//! \brief The constructor
	//! \param ix the position x coordinate
	//! \param iy the position y coordinate
	//! \param iz the position z coordinate
	//! \param ivx the position x speed coordinate
	//! \param ivy the position y speed coordinate
	//! \param ivz the position z speed coordinate
	//! \param iax the position euler angle around x axis
	//! \param iay the position euler angle around y axis
	//! \param iaz the position euler angle around z axis
	//! \param ivax the position rotation speed around x axis
	//! \param ivay the position rotation speed around y axis
	//! \param ivaz the position rotation speed around z axis
	Tcoord( double ix, double iy, double iz, double ivx, double ivy, double ivz, double iax, double iay, double iaz, double ivax, double ivay, double ivaz) :
		x( ix), y( iy), z( iz), vx( ivx), vy( ivy), vz( ivz), ax( iax), ay( iay), az( iaz), vax( ivax), vay( ivay), vaz( ivaz)
	{
	}
};

//***************************************************************************
struct TGLObject : public Tcoord
//----------------------------------------------------------------------------
//! class for GL display list characterisation
//! \todo get rid of the double coordinate representation and introduce vectors
//***************************************************************************
{
	unsigned int *obj;//!< pointer to the GL display List represented by the TGLObject

	//! \brief The constructor
	//! \param io pointer to the GL List represented by the TGLObject
	//! \param ix the position x coordinate
	//! \param iy the position y coordinate
	//! \param iz the position z coordinate
	//! \param ivx the position x speed coordinate
	//! \param ivy the position y speed coordinate
	//! \param ivz the position z speed coordinate
	//! \param iax the position euler angle around x axis
	//! \param iay the position euler angle around y axis
	//! \param iaz the position euler angle around z axis
	//! \param ivax the position rotation speed around x axis
	//! \param ivay the position rotation speed around y axis
	//! \param ivaz the position rotation speed around z axis
	TGLObject( unsigned int *io, double ix, double iy, double iz, double ivx, double ivy, double ivz, double iax, double iay, double iaz, double ivax, double ivay, double ivaz) :
		Tcoord( ix, iy, iz, ivx, ivy, ivz, iax, iay, iaz, ivax, ivay, ivaz), obj( io)
	{
	}
};

//***************************************************************************
struct TGLLight : public Tcoord
//----------------------------------------------------------------------------
//! class for GL lights characterisation
//! \todo get rid of the double coordinate representation and introduce vectors
//***************************************************************************
{
	GLenum id; //!<the id of the light
	GLenum kind; //!< the kind of light

	//! No directional lights supported so no angles here! also sets up an initial strength
	//! and color for the lights
	//! \brief The constructor
	//! \param iid the id of the light
	//! \param ikind the kind of light( currently supported GL_AMBIENT, GL_DIFFUSE and GL_SPECULAR)
	//! \param ix the position x coordinate
	//! \param iy the position y coordinate
	//! \param iz the position z coordinate
	//! \param ivx the position x speed coordinate
	//! \param ivy the position y speed coordinate
	//! \param ivz the position z speed coordinate
	TGLLight( int iid, GLenum ikind, double ix, double iy, double iz, double ivx, double ivy, double ivz) :
		Tcoord( ix, iy, iz, ivx, ivy, ivz, 0, 0, 0, 0, 0, 0), id( GL_LIGHT0+iid), kind( ikind)
	{
		GLfloat Ldef[]= { 0.8, 0.8, 0.8, 1.0 };
		GLfloat LNull[]={ 0., 0., 0., 1.0};
		GLfloat LPos[]= { ix, iy, iz, 1. };

		switch(kind)
		{
			case GL_AMBIENT:
				glLightfv( id, GL_AMBIENT, Ldef);
				glLightfv( id, GL_DIFFUSE, LNull);
				glLightfv( id, GL_SPECULAR, LNull);
				break;
			case GL_DIFFUSE:
				glLightfv( id, GL_AMBIENT, LNull);
				glLightfv( id, GL_DIFFUSE, Ldef);
				glLightfv( id, GL_SPECULAR, LNull);
				break;
			case GL_SPECULAR:
				glLightfv( id, GL_AMBIENT, LNull);
				glLightfv( id, GL_DIFFUSE, LNull);
				glLightfv( id, GL_SPECULAR, Ldef);
				break;
		}

		glLightfv( id, GL_POSITION, LPos );
		glEnable( id);
	}

	//! \brief changes the Lights Color setup
	//! \param r the red value of the light color
	//! \param g the green value of the light color
	//! \param b the blue value of the light color
	//! \param ikind the kind of light to be manipulated
	//! \param alpha the lights alpha value
	void Color( double r, double g, double b, GLenum ikind = 0, double alpha = 1)
	{
		GLfloat Col[] = { r, g, b, alpha};
		if( ikind == 0)glLightfv( id, kind, Col);
		else glLightfv( id, ikind, Col);
	}
};

//***************************************************************************
class GLView : public QGLWidget
//----------------------------------------------------------------------------
//! It is derived from QGLWidget and extendend for animation, scroll and zoom
//! functionality\n
//! \attention Init() before first showing the widget
//! \attention all slots will just take effect if called \em after widget is made visible
//! \todo add exceptions
//! \todo strip the engine class (GLView) from all specific drawing functionality
//! \todo add auto speed regulation
//***************************************************************************
{
	Q_OBJECT

public:

	//! \brief Constructor, derived from the QGLWidget Constructor
	//! \param parent the parent widged (0 if top level)
	//! \param name the name of the widget
	GLView( QWidget *parent, char const *name);
	//! \brief Destructor
	~GLView();

	//! \brief Set up everything that has to be set up (non OpenGL stuff)
	//! \attention must be called before the Widget is made visible
	//! \param sm The GL shading model
	//! \param df The GL depth function
	//! \param in the time intervall for the widgets timer (in ms)
	virtual void Init( const unsigned int sm = GL_SMOOTH, const unsigned int df = GL_LEQUAL, const int in = 50);

public slots:

	//! \brief enable/disable lighting globally
	//! \param sw true = enable, \n false = disable
	void enableLights( bool sw);
	//! \brief enable/disable Mouse Scrolling
	//! \param sw true = enable, \n false = disable
	void enableMouseScroll( bool sw) { doscr = sw;}
	//! \brief enable/disable Mouse zooming
	//! \param sw true = enable, \n false = disable
	void enableMouseZoom( bool sw){ dozoo = sw;}
	//! \brief enable/disable moving of the reference point
	//! \param sw true = enable, \n false = disable
	void enableMouseMove( bool sw){ domoo = sw;}
	//! clears the content of the gl Widget
	void clear();

	//! starts playing
	virtual int play();

	//! \brief activates/deactivates fog
	//! \param sw true = enable, \n false = disable
	//! \param density the fog density
	//! \param start at which length away from the camera the fog starts
	//! \param end at which length away from the camera the fog ends
	//! \param r the red value of the fog color
	//! \param g the green value of the fog color
	//! \param b the blue value of the fog color
	virtual void enableFog( bool sw, double density = 0.35, double start=1., double end=5., double r=0.5, double g=0.5, double b=0.5);


protected:
	unsigned int axes; //!< the coordinate axes
	unsigned int grid; //!< a grid
	unsigned int cont; //!< a plain surface to display shadows on (test)

	unsigned int glSM, glDF;
	unsigned int scene;
	bool fswitch, sswitch, mswitch;

	Tcoord *Cam;

	vector<TGLObject> ois;
	vector<TGLObject>::iterator itois;

	vector<TGLLight> lights;
	vector<TGLLight>::iterator itlights;

	vector<unsigned int> shades;
	vector<unsigned int>:: iterator itshades;

	map<string, unsigned int> textures;

	//! \brief overloaded member function inherited from QGLWidget sets up all OpenGL related stuff
	virtual void initializeGL();
	//! \brief overloaded member function inherited from QGLWidget handles everything when resizing comes to term
	//! \param w new window width
	//! \param h new window height
	void resizeGL( const int w, const int h);
	//! \brief overloaded member function inherited from QGLWidget does the actual drawing
	void paintGL();

	//! \brief mouse key response
	void mousePressEvent( QMouseEvent *);
	//! \brief mouse move response (e.g. scrolling or zooming)
	void mouseMoveEvent( QMouseEvent *);
	//! \brief mouse release -> return to normal state
	void mouseReleaseEvent( QMouseEvent *);
	//! \brief response to key events needed for moving of reference point
	void keyPressEvent( QKeyEvent *);
	//! \brief to be overwritten in derived classes for Key events
	virtual void evKeyPress( QKeyEvent *) {};
	//! \brief timer for the demo
	void timerEvent( QTimerEvent *);

	//! This function acts as a kind of film script for the demo
	//! \brief this is the function that actually directs the demo
	virtual void director() {};
	//! \brief moves the lights according to their velocities (actually no need to overload)
	virtual void adjustLights() {};
	//! \brief moves the camera according to its velocities  (actually no need to overload either)
	virtual void adjustCamera() {};
	//! \brief moves the objects in the scene according to their velocities
	virtual void adjustScene() {};
	//! \brief makes if activated the objects shadows
	//! \attention only support for non rotating cubes till now
	virtual void makeShades() {};

	virtual void makeCont() {};
private:

	void initMoving( bool esc = false);

	void moveCursor( QMouseEvent *);

// object making functions
	void makeCursor();
	void makeAxes();
	void makeGrid();

	bool axis;
	bool doscr; //!< mouse scroll enabled
	bool dozoo; //!< mouse zoom enabled
	bool domoo; //!< mouse move enabled

	unsigned int mcursor;

	GLUquadricObj *quadratic; //!< used for displaying a sphere (e.g. cursor in move function)


	int timerID; //!< ID of the timer used to control the replay speed
	int timeIndex; //!< what time it is (during the replay)
	int timeIntervall; //!< intervall of the timer id est replay speed

	GLfloat xm, ym, zm;
	double zoom; //!< speed factor of mouse zoom
	bool lbut, rbut, showGrid;
	int curs, curs2;
	QPoint cPos, cPos2, GPoint;
	double Rx, Ry, Rz, cx1, cy1, cursx, cursy, cursz, cxh, cyh;

};

#endif