float AnimationSegment::overlap( const AnimationSegment& seg ) const
{
	if( mAnim != seg.getAnimation() )
		return 0;

	AnimationSegment seg1 = *this,
		seg2 = seg;
	
	if( seg2.mStartTime < seg1.mStartTime )
		std::swap( seg1, seg2 );

	float l_int = 0; // length of the intersection

	if( seg2.mStartTime < seg1.mEndTime )
	{
		if( seg2.mEndTime <= seg1.mEndTime )
			l_int = seg2.mEndTime - seg2.mStartTime;
		else
			l_int = seg1.mEndTime - seg2.mStartTime;
	}

	float l_seg = std::min<float>( seg1.mEndTime - seg1.mStartTime,
		seg2.mEndTime - seg2.mStartTime ); // length of the shorter segment

	return l_int/l_seg;
}
AnimationSegment AnimationSegment::merge( const AnimationSegment& seg ) const
{
	if( mAnim != seg.getAnimation() )
		return AnimationSegment( mAnim, 0, 0 );

	AnimationSegment seg1 = *this,
		seg2 = seg;
	
	if( seg2.mStartTime < seg1.mStartTime )
		std::swap( seg1, seg2 );

	if( seg2.mStartTime < seg1.mEndTime )
	{
		if( seg2.mEndTime <= seg1.mEndTime )
			return seg1;
		else
			return AnimationSegment( mAnim, seg1.mStartTime, seg2.mEndTime );
	}

	return AnimationSegment( mAnim, 0, 0 );
}