/*
-----------------------------------------------------------------------------
Copyright (c) 2010 Jacob 'jacmoe' Moen
 
You may use this sample code for anything you like, it is public domain.
-----------------------------------------------------------------------------
*/
/*
-----------------------------------------------------------------------------
Filename:    AnimationSerializer.cpp
Description: A serializer for keyframe animations
-----------------------------------------------------------------------------
*/
 
#include "AnimationSerializer.h"
 
#include "OgrePrerequisites.h"
#include "OgreException.h"
#include "OgreAnimation.h"
#include "OgreAnimationTrack.h"
#include "OgreKeyFrame.h"
#include "OgreString.h"
#include "OgreDataStream.h"
#include "OgreLogManager.h"
#include "OgreResourceGroupManager.h"
#include "OgreStringConverter.h"
 
/// stream overhead = ID + size
const long STREAM_OVERHEAD_SIZE = sizeof(Ogre::uint16) + sizeof(Ogre::uint32);
 
AnimationSerializer::AnimationSerializer()
{
	mVersion = "[AnimationSerializer.10]";
}
 
AnimationSerializer::~AnimationSerializer()
{
 
}
 
void AnimationSerializer::exportAnimation(const Ogre::Animation* pAnimation, const Ogre::String& filename,
	Endian endianMode)
{
	// Decide on endian mode
	determineEndianness(endianMode);
 
	Ogre::String msg;
	mpfFile = fopen(filename.c_str(), "wb");
	if (!mpfFile)
	{
		OGRE_EXCEPT(Ogre::Exception::ERR_CANNOT_WRITE_TO_FILE,
			"Unable to open file " + filename + " for writing",
			"AnimationSerializer::exportAnimation");
	}
 
	writeFileHeader();
 
	Ogre::LogManager::getSingleton().stream()
		<< "Exporting animation: " << pAnimation->getName();
	writeAnimation(pAnimation);
 
	Ogre::LogManager::getSingleton().logMessage("Animation exported.");
 
	fclose(mpfFile);
 
}
 
Ogre::Animation* AnimationSerializer::importAnimation(const Ogre::String& filename)
{
	Ogre::DataStreamPtr stream = Ogre::ResourceGroupManager::getSingleton().openResource(filename);
	return importAnimation(stream);
 
}
 
Ogre::Animation* AnimationSerializer::importAnimation(Ogre::DataStreamPtr& stream)
{
	// Determine endianness (must be the first thing we do!)
	determineEndianness(stream);
 
	// Check header
	readFileHeader(stream);
 
	Ogre::Animation* anim;
 
	unsigned short streamID;
	while(!stream->eof())
	{
		streamID = readChunk(stream);
		switch (streamID)
		{
		case AC_ANIMATION:
			anim = readAnimation(stream);
			break;
		}
	}
	return anim;
}
 
void AnimationSerializer::writeAnimation(const Ogre::Animation* anim)
{
	writeChunkHeader(AC_ANIMATION, calcAnimationSize(anim));
 
	// char* name                       : Name of the animation
	writeString(anim->getName());
	// float length                      : Length of the animation in seconds
	float len = anim->getLength();
	writeFloats(&len, 1);
 
	// Write all tracks
	Ogre::Animation::NodeTrackIterator trackIt = anim->getNodeTrackIterator();
	while(trackIt.hasMoreElements())
	{
		writeAnimationTrack(trackIt.getNext());
	}
}
 
void AnimationSerializer::writeAnimationTrack(const Ogre::NodeAnimationTrack* track)
{
	static unsigned short trackId = 0;
	writeChunkHeader(AC_ANIMATION_TRACK, calcAnimationTrackSize(track));
 
	writeShorts(&trackId, 1);
 
	// Write all keyframes
	for (unsigned short i = 0; i < track->getNumKeyFrames(); ++i)
	{
		writeKeyFrame(track->getNodeKeyFrame(i));
	}
	trackId++;
}
 
void AnimationSerializer::writeKeyFrame(const Ogre::TransformKeyFrame* key)
{
	writeChunkHeader(AC_ANIMATION_TRACK_KEYFRAME, 
		calcKeyFrameSize(key));
 
	// float time                    : The time position (seconds)
	float time = key->getTime();
	writeFloats(&time, 1);
	// Quaternion rotate            : Rotation to apply at this keyframe
	writeObject(key->getRotation());
	// Vector3 translate            : Translation to apply at this keyframe
	writeObject(key->getTranslate());
}
 
Ogre::Animation* AnimationSerializer::readAnimation(Ogre::DataStreamPtr& stream)
{
	Ogre::String name;
	name = readString(stream);
	// float length                      : Length of the animation in seconds
	float len;
	readFloats(stream, &len, 1);
 
	Ogre::Animation* anim = new Ogre::Animation(name, len);
 
	// Read all tracks
	if (!stream->eof())
	{
		unsigned short streamID = readChunk(stream);
		while(streamID == AC_ANIMATION_TRACK && !stream->eof())
		{
			readAnimationTrack(stream, anim);
 
			if (!stream->eof())
			{
				// Get next stream
				streamID = readChunk(stream);
			}
		}
		if (!stream->eof())
		{
			// Backpedal back to start of this stream if we've found a non-track
			stream->skip(-STREAM_OVERHEAD_SIZE);
		}
 
	}
	return anim;
}
 
void AnimationSerializer::readAnimationTrack(Ogre::DataStreamPtr& stream, Ogre::Animation* anim)
{
	unsigned short trackId;
	readShorts(stream, &trackId, 1);
	// Create track
	Ogre::NodeAnimationTrack* pTrack = anim->createNodeTrack(trackId);
 
	// Keep looking for nested keyframes
	if (!stream->eof())
	{
		unsigned short streamID = readChunk(stream);
		while(streamID == AC_ANIMATION_TRACK_KEYFRAME && !stream->eof())
		{
			readKeyFrame(stream, pTrack);
 
			if (!stream->eof())
			{
				// Get next stream
				streamID = readChunk(stream);
			}
		}
		if (!stream->eof())
		{
			// Backpedal back to start of this stream if we've found a non-keyframe
			stream->skip(-STREAM_OVERHEAD_SIZE);
		}
 
	}
}
 
void AnimationSerializer::readKeyFrame(Ogre::DataStreamPtr& stream, Ogre::NodeAnimationTrack* track)
{
	// float time                    : The time position (seconds)
	float time;
	readFloats(stream, &time, 1);
 
	Ogre::TransformKeyFrame *kf = track->createNodeKeyFrame(time);
 
	// Quaternion rotate            : Rotation to apply at this keyframe
	Ogre::Quaternion rot;
	readObject(stream, rot);
	kf->setRotation(rot);
	// Vector3 translate            : Translation to apply at this keyframe
	Ogre::Vector3 trans;
	readObject(stream, trans);
	kf->setTranslate(trans);
}
 
size_t AnimationSerializer::calcAnimationSize(const Ogre::Animation* pAnim)
{
	size_t size = STREAM_OVERHEAD_SIZE;
 
	// Name, including terminator
	size += pAnim->getName().length() + 1;
	// length
	size += sizeof(float);
 
	// Nested animation tracks
	Ogre::Animation::NodeTrackIterator trackIt = pAnim->getNodeTrackIterator();
	while(trackIt.hasMoreElements())
	{
		size += calcAnimationTrackSize(trackIt.getNext());
	}
 
	return size;
}
 
size_t AnimationSerializer::calcAnimationTrackSize(const Ogre::NodeAnimationTrack* pTrack)
{
	size_t size = STREAM_OVERHEAD_SIZE;
 
	// unsigned short boneIndex     : Index of bone to apply to
	size += sizeof(unsigned short);
 
	// Nested keyframes
	for (unsigned short i = 0; i < pTrack->getNumKeyFrames(); ++i)
	{
		size += calcKeyFrameSize(pTrack->getNodeKeyFrame(i));
	}
 
	return size;
}
 
size_t AnimationSerializer::calcKeyFrameSize(const Ogre::TransformKeyFrame* pKey)
{
	size_t size = STREAM_OVERHEAD_SIZE;
 
	// float time                    : The time position (seconds)
	size += sizeof(float);
	// Quaternion rotate            : Rotation to apply at this keyframe
	size += sizeof(float) * 4;
	// Vector3 translate            : Translation to apply at this keyframe
	size += sizeof(float) * 3;
 
	return size;
}