physics.h

/* --------------------------------------------------------------------
EXTREME TUXRACER

Copyright (C) 1999-2001 Jasmin F. Patry (Tuxracer)
Copyright (C) 2010 Extreme Tuxracer Team

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
of the License, or (at your option) any later version.

This program 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.
---------------------------------------------------------------------*/

#ifndef PHYSICS_H
#define PHYSICS_H

#include "bh.h"

#define MAX_PADDLING_SPEED (60.0 / 3.6)   /* original 60 */
#define PADDLE_FACT 1.0 /* original 1.0 */

#define EARTH_GRAV 9.81  /* ok, why not 10.0 ? */
#define JUMP_FORCE_DURATION 0.20
#define TUX_MASS 20				
#define MIN_TUX_SPEED 1.4 
#define INIT_TUX_SPEED 3.0
#define COLL_TOLERANCE 0.1		

#define MAX_SURF_PEN 0.2		
#define TUX_Y_CORR 0.36			
#define IDEAL_ROLL_SPEED 6.0	
#define IDEAL_ROLL_FRIC 0.35	
#define WIND_FACTOR 1.5

#define MIN_FRICT_SPEED 2.8		
#define MAX_FRICT_FORCE 800		
#define MAX_TURN_ANGLE 45
#define MAX_TURN_PERP 400		
#define MAX_TURN_PEN 0.15		
#define PADDLING_DURATION 0.40  
#define IDEAL_PADD_FRIC 0.35	
#define MAX_PADD_FORCE 122.5	
#define BRAKE_FORCE 200

#define MIN_TIME_STEP 0.01
#define MAX_TIME_STEP 0.10
#define MAX_STEP_DIST 0.20		
#define MAX_POS_ERR 0.005		
#define MAX_VEL_ERR	0.05		

// constants for finish stage
#define FIN_AIR_GRAV 500
#define FIN_GRAV 500
#define FIN_AIR_BRAKE 20
#define FIN_BRAKE 12

typedef struct {
	TVector3 surfnml;
	TVector3 rollnml;
	TVector3 pos;
	TVector3 vel;
	TVector3 frictdir;

	double frict_coeff;
	double comp_depth;
	double surfdistance;
    double compression;	
} TForce;

class CControl {
private:
	double ode_time_step;
	TForce ff;
	double finish_speed;

	bool     CheckTreeCollisions (TVector3 pos, TVector3 *tree_loc, double *tree_diam);
	void     AdjustTreeCollision (TVector3 pos, TVector3 *vel);
	void     CheckItemCollection (TVector3 pos);

	TVector3 CalcRollNormal (double speed);
	TVector3 CalcAirForce ();
	TVector3 CalcSpringForce ();
	TVector3 CalcNormalForce ();
	TVector3 CalcJumpForce ();
	TVector3 CalcFrictionForce (double speed, TVector3 nmlforce);
	TVector3 CalcPaddleForce (double speed);
	TVector3 CalcBrakeForce (double speed);
	TVector3 CalcGravitationForce ();
	TVector3 CalcNetForce (TVector3 pos, TVector3 vel);
	TVector3 CalcFinishForce (TVector3 pos, TVector3 vel);

	void     AdjustVelocity (TPlane surf_plane);
	void     AdjustPosition (TPlane surf_plane, double dist_from_surface);
	void     SetTuxPosition (double speed);
	double   AdjustTimeStep (double h, TVector3 vel);
	void     SolveOdeSystem (double timestep);
public:
	CControl ();
	~CControl ();
	
	// view:
	TViewMode viewmode;                
    TVector3 viewpos;                     
    TVector3 plyr_pos;                
    TVector3 viewdir;                    
    TVector3 viewup;                     
    TMatrix view_mat;         
    bool view_init;              
	// main:
	TVector3 cpos;          
    TVector3 cvel;    
	TVector3 last_pos;
    TVector3 cnet_force;        
    TVector3 cdirection;        
	TQuaternion corientation;        
	double way;
	
    bool orientation_initialized;  
    TVector3 plane_nml;              
	// steering:
    double turn_fact;              
    double turn_animation;         
	double paddle_time;
    bool   is_paddling;              
    bool   is_braking;               
    bool   begin_jump;
    bool   jumping;
    bool   jump_charging;
    double jump_amt;
    double jump_start_time;
	// trick:
    double roll_factor;
    double flip_factor;
    bool   front_flip;
    bool   back_flip;
    bool   cairborne;           
    bool   roll_left;
    bool   roll_right;
	// pseudo constants:
	double minSpeed;
	double minFrictspeed;

	void Init ();
	void UpdatePlayerPos (double timestep);
};

// STRUCTURE OF PHYSICS.CPP

// ------------------- init -------------------------------------------
// void InitSimulation ()

// ----------------- collision ----------------------------------------
// bool  CheckTreeCollisions (TVector3 pos, TVector3 *tree_loc, double *tree_diam)
// void  AdjustTreeCollision (TVector3 pos, TVector3 *vel)
// void  CheckItemCollection (TVector3 pos)

// ----------------- position and vlelocity ---------------------------
// double AdjustVelocity (TVector3 *vel, TVector3 pos, TPlane surf_plane, 
// 	   double dist_from_surface)
// void   AdjustPosition (TVector3 *pos, TPlane surf_plane, double dist_from_surface)
// void   SetTuxPosition (TVector3 new_pos)

// ----------------- forces -------------------------------------------
// TVector3 AdjustRollNormal (TVector3 vel, double fric_coeff, TVector3 nml)
// TVector3 CalcAirForce (TVector3 player_vel)
// TVector3 CalcSpringForce (double compression, TVector3 vel, TVector3 surf_nml)
// TVector3 CalcNetForce (TVector3 pos, TVector3 vel)

// ------------------ ODE solver and port function
// static double adjust_time_step_size (double h, TVector3 vel)
// void   SolveOdeSystem (double timestep)
// void   UpdatePlayerPos (double timestep)

#endif