+// $Id$
//
-// C Implementation: physic
+// SuperTux
+// Copyright (C) 2004 Tobias Glaesser <tobi.web@gmx.de>
+// Copyright (C) 2006 Matthias Braun <matze@braunis.de>
//
-// Description:
+// 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.
//
-// Author: Tobias Glaesser <tobi.web@gmx.de>, (C) 2004
-//
-// Copyright: See COPYING file that comes with this distribution
-//
-//
-#include <stdio.h>
-
-#include "scene.h"
-#include "defines.h"
-#include "physic.h"
-#include "timer.h"
+// 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 <config.h>
-float gravity;
+#include "physic.hpp"
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(float nvx, float nvy)
-{
- vx = nvx;
- vy = -nvy;
-}
-
-float
-Physic::get_velocity_x()
-{
- return vx;
-}
-
-float
-Physic::get_velocity_y()
+ : ax(0), ay(0), vx(0), vy(0), gravity_enabled(true), gravity(1000)
{
- return -vy;
}
-void
-Physic::set_acceleration(float nax, float nay)
+Vector
+Physic::get_movement(float elapsed_time)
{
- ax = nax;
- ay = -nay;
-}
-
-float
-Physic::get_acceleration_x()
-{
- return ax;
-}
+ float grav = gravity_enabled ? gravity : 0;
-float
-Physic::get_acceleration_y()
-{
- return -ay;
-}
-
-void
-Physic::enable_gravity(bool enable_gravity)
-{
- gravity_enabled = enable_gravity;
-}
-
-void
-Physic::apply(float &x, float &y)
-{
- float grav;
- if(gravity_enabled)
- grav = gravity / 100.0;
- else
- grav = 0;
+ Vector result(
+ vx * elapsed_time + ax * elapsed_time * elapsed_time,
+ vy * elapsed_time + (ay + grav) * elapsed_time * elapsed_time
+ );
+ vx += ax * elapsed_time;
+ vy += (ay + grav) * elapsed_time;
- x += vx * frame_ratio + ax * frame_ratio * frame_ratio;
- y += vy * frame_ratio + (ay + grav) * frame_ratio * frame_ratio;
- vx += ax * frame_ratio;
- vy += (ay + grav) * frame_ratio;
+ return result;
}