/* animator.h
   Used by guile functions to easily get a soft transition of real values

   Copyright (C) 2000  Mathias Broxvall

   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 "general.h"
#include "gameHook.h"
#include "animator.h"

using namespace std;

Animator::Animator(Real length,Real position,Real direction,Real v0, Real v1, int repeat,SCM fun) 
  :length(length), position(fmod(position,1.0)), direction(direction), value0(v0), value1(v1), repeat(repeat), fun(fun)
{ if(fun) scm_gc_protect_object(fun); }
Animator::~Animator() { if(fun) scm_gc_unprotect_object(fun); this->GameHook::~GameHook(); }
Real Animator::getValue() { return value0 * (1.0 - position/length) + position/length * value1; }
void Animator::tick(Real td) { 
  if(!direction) return;
  position += td * direction;
  if(position <= 0 && repeat & ANIMATOR_0_STOP) { direction=0.0; position=0.0; }
  if(position <= 0 && repeat & ANIMATOR_0_BOUNCE) { direction=-direction; position=-position; }
  if(position <= 0 && repeat & ANIMATOR_0_WRAP) { position=length + position; }
  if(position >= length && repeat & ANIMATOR_1_STOP) { direction=0.0; position=length; }
  if(position >= length && repeat & ANIMATOR_1_BOUNCE) { direction=-direction; position=length*2.0-position; }
  if(position >= length && repeat & ANIMATOR_1_WRAP) { position=position - length; }

  scm_apply_1(fun,scm_double2num(getValue()),SCM_EOL);

  if(position <= 0 && repeat & ANIMATOR_0_REMOVE) { remove(); return; }
  if(position >= length && repeat & ANIMATOR_1_REMOVE) { remove(); return; }
}