[Super-tux-commit] supertux/lib/math physic.cpp,NONE,1.1 physic.h,NONE,1.1 vector.cpp,NONE,1.1 vector.h,NONE,1.1

[Tobias G. <to...@us...>]

Update of /cvsroot/super-tux/supertux/lib/math
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv19557/lib/math

Added Files:
	physic.cpp physic.h vector.cpp vector.h 
Log Message:
Generated SuperTux libtool library containing more general source, that could prove useful for other applications/games.
Caution: It's not yet SuperTux independed, more work on this will follow, that's just the first step.
The file structure isn't fixed, better ideas will surely find there way in it!

--- NEW FILE: vector.cpp ---
//  $Id: vector.cpp,v 1.1 2004/07/20 17:51:36 tobgle Exp $
//
//  SuperTux -  A Jump'n Run
//  Copyright (C) 2004 Matthias Braun <ma...@br...
//
//  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.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

#include <cmath>

#include "math/vector.h"

Vector Vector::unit() const
{
  return *this / norm();
}

float Vector::norm() const
{
  return sqrt(x*x + y*y);
}

--- NEW FILE: vector.h ---
//  $Id: vector.h,v 1.1 2004/07/20 17:51:36 tobgle Exp $
//
//  SuperTux -  A Jump'n Run
//  Copyright (C) 2004 Matthias Braun <ma...@br...
//
//  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.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

#ifndef SUPERTUX_VECTOR_H
#define SUPERTUX_VECTOR_H

class Vector
{
public:
  Vector(float nx, float ny)
    : x(nx), y(ny)
  { }
  Vector(const Vector& other)
    : x(other.x), y(other.y)
  { }
  Vector()
    : x(0), y(0)
  { }

  bool operator ==(const Vector& other) const
  {
    return x == other.x && y == other.y;
  }

  const Vector& operator=(const Vector& other)
  {
    x = other.x;
    y = other.y;
    return *this;
  }

  Vector operator+(const Vector& other) const
  {
    return Vector(x + other.x, y + other.y);
  }

  Vector operator-(const Vector& other) const
  {
    return Vector(x - other.x, y - other.y);
  }

  Vector operator*(float s) const
  {
    return Vector(x * s, y * s);
  }

  Vector operator/(float s) const
  {
    return Vector(x / s, y / s);
  }

  Vector operator-() const
  {
    return Vector(-x, -y);
  }

  const Vector& operator +=(const Vector& other)
  {
    x += other.x;
    y += other.y;
    return *this;
  }

  // scalar product of 2 vectors
  float operator*(const Vector& other) const
  {
    return x*other.x + y*other.y;
  }

  float norm() const;
  Vector unit() const;

  // ... add the other operators as needed, I'm too lazy now ...

  float x, y; // leave this public, get/set methods just give me headaches
              // for such simple stuff :)
};

#endif /*SUPERTUX_VECTOR_H*/


--- NEW FILE: physic.cpp ---
//  $Id: physic.cpp,v 1.1 2004/07/20 17:51:36 tobgle Exp $
// 
//  SuperTux
//  Copyright (C) 2004 Tobias Glaesser <tob...@gm...>
//
//  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.
// 
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
//  02111-1307, USA.

#include <cstdio>

#include "math/physic.h"
#include "special/timer.h"

Physic::Physic()
    : ax(0), ay(0), vx(0), vy(0), gravity_enabled(true)
{
}

Physic::~Physic()
{
}

void
Physic::reset()
{
    ax = ay = vx = vy = 0;
    gravity_enabled = true;
}

void
Physic::set_velocity_x(float nvx)
{
  vx = nvx;
}

void
Physic::set_velocity_y(float nvy)
{
  vy = -nvy;
}

void
Physic::set_velocity(float nvx, float nvy)
{
  vx = nvx;
  vy = -nvy;
}

void Physic::inverse_velocity_x()
{
vx = -vx;
}

void Physic::inverse_velocity_y()
{
vy = -vy;
}

float
Physic::get_velocity_x()
{
    return vx;
}

float
Physic::get_velocity_y()
{
    return -vy;
}

void
Physic::set_acceleration_x(float nax)
{
  ax = nax;
}

void
Physic::set_acceleration_y(float nay)
{
  ay = -nay;
}

void
Physic::set_acceleration(float nax, float nay)
{
    ax = nax;
    ay = -nay;
}

float
Physic::get_acceleration_x()
{
    return ax;
}

float
Physic::get_acceleration_y()
{
    return -ay;
}

void
Physic::enable_gravity(bool enable_gravity)
{
  gravity_enabled = enable_gravity;
}

void
Physic::apply(float elapsed_time, float &x, float &y, float& gravity)
{
  float grav;
  if(gravity_enabled)
    grav = gravity / 100.0;
  else
    grav = 0;

  x += vx * elapsed_time + ax * elapsed_time * elapsed_time;
  y += vy * elapsed_time + (ay + grav) * elapsed_time * elapsed_time;
  vx += ax * elapsed_time;
  vy += (ay + grav) * elapsed_time;
}

void
Physic::apply(Vector& vector, float elapsed_time, float& gravity)
{
  apply(elapsed_time, vector.x, vector.y, gravity);
}


--- NEW FILE: physic.h ---
//  $Id: physic.h,v 1.1 2004/07/20 17:51:36 tobgle Exp $
// 
//  SuperTux
//  Copyright (C) 2004 Tobias Glaesser <tob...@gm...>
//
//  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.
// 
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
//  02111-1307, USA.

#ifndef SUPERTUX_PHYSIC_H
#define SUPERTUX_PHYSIC_H

#include "math/vector.h"

/** This is a very simplistic physics engine handling accelerated and constant
  * movement along with gravity.
  */
class Physic
{
public:
    Physic();
    ~Physic();

    /** resets all velocities and accelerations to 0 */
    void reset();

    /** sets velocity to a fixed value */
    void set_velocity(float vx, float vy);

    void set_velocity_x(float vx);
    void set_velocity_y(float vy);

    /** velocities invertion */
    void inverse_velocity_x();
    void inverse_velocity_y();

    float get_velocity_x();
    float get_velocity_y();
    
    /** sets acceleration applied to the object. (Note that gravity is
     * eventually added to the vertical acceleration)
     */
    void set_acceleration(float ax, float ay);

    void set_acceleration_x(float ax);
    void set_acceleration_y(float ay);

    float get_acceleration_x();
    float get_acceleration_y();

    /** enables or disables handling of gravity */
    void enable_gravity(bool gravity_enabled);

    /** applies the physical simulation to given x and y coordinates */
    void apply(float frame_ratio, float &x, float &y, float& gravity = 10); 

    /** applies the physical simulation to given x and y coordinates */
    void apply(Vector& vector, float frame_ratio, float& gravity = 10);

private:
    /// horizontal and vertical acceleration
    float ax, ay;
    /// horizontal and vertical velocity
    float vx, vy;
    /// should we respect gravity in out calculations?
    bool gravity_enabled;
};

#endif /*SUPERTUX_PHYSIC_H*/