/*=========================================================================

  Program:   ParaView
  Module:    vtkSequenceAnimationPlayer.cxx

  Copyright (c) Kitware, Inc.
  All rights reserved.
  See Copyright.txt or http://www.paraview.org/HTML/Copyright.html for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkSequenceAnimationPlayer.h"

#include "vtkObjectFactory.h"

vtkStandardNewMacro(vtkSequenceAnimationPlayer);
//----------------------------------------------------------------------------
vtkSequenceAnimationPlayer::vtkSequenceAnimationPlayer()
{
  this->NumberOfFrames = 10;
  this->FrameNo = 0;
}

//----------------------------------------------------------------------------
vtkSequenceAnimationPlayer::~vtkSequenceAnimationPlayer()
{
}

//----------------------------------------------------------------------------
void vtkSequenceAnimationPlayer::StartLoop(double starttime, double endtime,
                                           double* playbackWindow)
{
  // the frame index is inited to 0 ONLY when an animation is not resumed from
  // an intermediate frame
  this->FrameNo = 0;
  
  this->StartTime = starttime;
  this->EndTime = endtime;
  
  // currenttime, which might be the 'scene time' (usually unequal to
  // starttime) upon the previous pause / stop operation (if any), is used to
  // determine the actual frame index from which to resume the animation
  if (playbackWindow[0] > starttime)
    {
    // let's resume from the frame NEXT to the one on which the animation WAS
    // paused / stopped
    this->FrameNo = static_cast<int>( (playbackWindow[0] - this->StartTime) *
                                      (this->NumberOfFrames - 1) / 
                                      (this->EndTime - this->StartTime) + 0.5
                                    ) + 1;

    // Let's compute the upper bounds in Frame unit
    this->MaxFrameWindow = static_cast<int>( (playbackWindow[1] - this->StartTime) *
                                      (this->NumberOfFrames - 1) /
                                      (this->EndTime - this->StartTime) + 0.5
                                    ) + 1;
    }
}

//----------------------------------------------------------------------------
double vtkSequenceAnimationPlayer::GetNextTime(double curtime)
{
  if(this->FrameNo == 0 && curtime > this->StartTime)
    {
    // Invalid Frame No, compute it correctly
    this->FrameNo = static_cast<int>( (curtime - this->StartTime) *
                                      (this->NumberOfFrames - 1) / 
                                      (this->EndTime - this->StartTime) + 0.5
                                    ) + 1;
    }
  this->FrameNo++;
  if (this->StartTime >= this->EndTime && this->FrameNo >= this->MaxFrameWindow)
    {
    return VTK_DOUBLE_MAX;
    }

  double time = this->StartTime + 
    ((this->EndTime - this->StartTime)*this->FrameNo)/(this->NumberOfFrames-1);
  return time;
}

//----------------------------------------------------------------------------
double vtkSequenceAnimationPlayer::GoToNext(double start, double end, double curtime)
{
  double delta = static_cast<double>(end-start)/(this->NumberOfFrames-1);
  return (curtime + delta);
}

//----------------------------------------------------------------------------
double vtkSequenceAnimationPlayer::GoToPrevious(double start, double end, double curtime)
{
  double delta = static_cast<double>(end-start)/(this->NumberOfFrames-1);
  return (curtime - delta);
}

//----------------------------------------------------------------------------
void vtkSequenceAnimationPlayer::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
}
