// Copyright (C) 2011-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

#include "nv/gfx/skeleton_instance.hh"

#include "nv/core/profiler.hh"

void nv::skeleton_binding::prepare( const mesh_nodes_data* node_data, const data_node_list& bone_data )
{
	if ( m_indices.empty() )
	{
		// TODO: either fixed size struct or static allocator
		hash_store< shash64, uint16 > bone_names;
		m_indices.resize( node_data->size() );

		for ( nv::uint16 bi = 0; bi < bone_data.size(); ++bi )
			bone_names[bone_data[bi].name] = bi;

		for ( uint32 n = 0; n < node_data->size(); ++n )
		{
			sint16 bone_id = -1;
			auto bi = bone_names.find( node_data->get_info( n ).name );
			if ( bi != bone_names.end() )
			{
				bone_id = sint16( bi->second );
			}
			m_indices[n] = bone_id;

		}
		m_bone_count = bone_data.size();
	}

	if ( m_key.size() == 0 )
	{
		for ( uint32 n = 0; n < node_data->size(); ++n )
			if ( ( *node_data )[n]->size() > 0 )
			{
				m_key = ( *node_data )[n]->get_interpolation_key();
				break;
			}
	}
}

void nv::skeleton_instance::assign( const skeleton_transforms& skeleton, const bone_transforms& bones )
{
	if ( bones.size() != m_matrix.size() ) 
		m_matrix.resize( bones.size() );
	const transform* transforms = skeleton.transforms();
	for ( uint32 n = 0; n < skeleton.size(); ++n )
	{
 		transform tr( bones.m_offsets[n] );
 		tr.set_orientation( normalize( tr.get_orientation() ) );
 		m_matrix[n] = ( transforms[n] * tr ).extract();
	//	m_matrix[n] = transforms[n].extract() * bones.m_offsets[n];
	}
}

void nv::skeleton_instance::assign( const bone_transforms& bones )
{
	if ( bones.size() != m_matrix.size() )
		m_matrix.resize( bones.size() );
}

void nv::skeleton_transforms::assign( const data_node_list* node_data )
{
	NV_ASSERT( node_data, "!!!" );
	if ( m_transforms.size() != node_data->size() )
		m_transforms.resize( node_data->size() );
	for ( uint32 n = 0; n < node_data->size(); ++n )
	{
		const data_node_info& info = (*node_data)[ n ];
		m_transforms[n] = transform( info.transform );
	}
}

void nv::skeleton_transforms::interpolate_linear( const skeleton_transforms& a, const skeleton_transforms& b, float t )
{
	NV_ASSERT( a.size() == b.size(), "!!!" );
	if ( m_transforms.size() != a.size() )
		m_transforms.resize( a.size() );
	for ( uint32 n = 0; n < a.size(); ++n )
	{
		m_transforms[n] = transform(
			math::mix( a.m_transforms[n].get_position(), b.m_transforms[n].get_position(), t ),
			math::lerp( a.m_transforms[n].get_orientation(), b.m_transforms[n].get_orientation(), t )
			);
	}

	if ( m_transforms.size() > 0 )
		m_transforms[0] = nv::interpolate( a.m_transforms[0], b.m_transforms[0], t );
}

void nv::skeleton_transforms::interpolate_nlerp( const skeleton_transforms& a, const skeleton_transforms& b, float t )
{
	NV_ASSERT( a.size() == b.size(), "!!!" );
	if ( m_transforms.size() != a.size() )
		m_transforms.resize( a.size() );

	for ( uint32 n = 0; n < a.size(); ++n )
	{
		m_transforms[n] = transform(
			math::mix( a.m_transforms[n].get_position(), b.m_transforms[n].get_position(), t ),
			math::nlerp( a.m_transforms[n].get_orientation(), b.m_transforms[n].get_orientation(), t )
			);
	}

	if ( m_transforms.size() > 0 )
		m_transforms[0] = nv::interpolate( a.m_transforms[0], b.m_transforms[0], t );
}


void nv::skeleton_transforms::interpolate_slerp( const skeleton_transforms& a, const skeleton_transforms& b, float t )
{
	NV_ASSERT( a.size() == b.size(), "!!!" );
	if ( m_transforms.size() != a.size() )
		m_transforms.resize( a.size() );
	for ( uint32 n = 0; n < a.size(); ++n )
	{
		m_transforms[n] = nv::interpolate( a.m_transforms[n], b.m_transforms[n], t );
	}
}

void nv::skeleton_transforms::interpolate4( const skeleton_transforms& s1, const skeleton_transforms& v1, const skeleton_transforms& v2, const skeleton_transforms& s2, float t )
{
	NV_ASSERT( s1.size() == s2.size(), "!!!" );
	NV_ASSERT( v1.size() == v2.size(), "!!!" );
	NV_ASSERT( s1.size() == v1.size(), "!!!" );
	if ( m_transforms.size() != s1.size() )
		m_transforms.resize( s1.size() );
	float interp_squared = t*t;
	float interp_cubed = interp_squared*t;
	float weights[4];
	weights[0] = 0.5f * ( -interp_cubed + 2.0f * interp_squared - t );
	weights[1] = 0.5f * ( 3.0f * interp_cubed - 5.0f * interp_squared + 2.0f );
	weights[2] = 0.5f * ( -3.0f * interp_cubed + 4.0f * interp_squared + t );
	weights[3] = 0.5f * ( interp_cubed - interp_squared );

	for ( uint32 n = 0; n < s1.size(); ++n )
	{
		quat qs1 = s1.m_transforms[n].get_orientation();
		quat qs2 = s2.m_transforms[n].get_orientation();
		quat qv1 = v1.m_transforms[n].get_orientation();
		quat qv2 = v2.m_transforms[n].get_orientation();

		float a = dot( qv1, qv2 ) > 0.0f ? 1.0f : -1.0f;

		quat qr = weights[0] * qs1 
				+ weights[1] * (a * qv1 )
				+ weights[2] * qv2 
				+ weights[3] * qs2;

		qr = normalize( qr );

 		if ( n == 0 ) 
			qr = nv::math::slerp( v1.m_transforms[n].get_orientation(), v2.m_transforms[n].get_orientation(), t );

		m_transforms[n] = transform(
			weights[0] * s1.m_transforms[n].get_position() +
			weights[1] * v1.m_transforms[n].get_position() +
			weights[2] * v2.m_transforms[n].get_position() +
			weights[3] * s2.m_transforms[n].get_position(),
			qr
		);
	}
}


void nv::skeleton_transforms::interpolate_squad( const skeleton_transforms& s1, const skeleton_transforms& v1, const skeleton_transforms& v2, const skeleton_transforms& s2, float t )
{
	NV_ASSERT( s1.size() == s2.size(), "!!!" );
	NV_ASSERT( v1.size() == v2.size(), "!!!" );
	NV_ASSERT( s1.size() == v1.size(), "!!!" );
	if ( m_transforms.size() != s1.size() )
		m_transforms.resize( s1.size() );

	for ( uint32 n = 0; n < s1.size(); ++n )
	{
		nv::quat ss1 = s1.m_transforms[n].get_orientation();
		nv::quat ss2 = s2.m_transforms[n].get_orientation();
		nv::quat q = normalize( nv::math::squad(
			v1.m_transforms[n].get_orientation(),
			v2.m_transforms[n].get_orientation(),
			nv::math::intermediate( ss1, v1.m_transforms[n].get_orientation(), v2.m_transforms[n].get_orientation() ),
			nv::math::intermediate( v1.m_transforms[n].get_orientation(), v2.m_transforms[n].get_orientation(), ss2 ),
			t ) );
		if ( n == 0 ) q = nv::math::slerp(
			v1.m_transforms[n].get_orientation(),
			v2.m_transforms[n].get_orientation(), t );

		m_transforms[n] = transform(
			mix( v1.m_transforms[n].get_position(), v2.m_transforms[n].get_position(), t ),
			q
			);
	}

}

void nv::skeleton_transforms::assign( const skeleton_transforms& other )
{
	m_transforms.assign( other.m_transforms );
}

void nv::skeleton_transforms::animate_local( const mesh_nodes_data* node_data, const skeleton_binding& binding, float frame )
{
	if ( m_transforms.size() != binding.skeleton_size() )
		m_transforms.resize( binding.skeleton_size() );
	for ( uint32 n = 0; n < node_data->size(); ++n )
	{
		const data_channel_set* node = ( *node_data )[n];
		sint16 bone_id = binding.m_indices[n];
		if ( bone_id >= 0 )
		{
			if ( node->size() > 0 )
			{
				m_transforms[bone_id] = raw_channel_interpolator( node, binding.m_key ).get< transform >( frame );
			}
			int confirm_that_not_needed;
// 			else
// 				m_transforms[bone_id] = transform( node->get_transform() );
		}
	}
}

void nv::skeleton_transforms::blend_local( const mesh_nodes_data* node_data, const skeleton_binding& binding, float frame, float blend )
{
	if ( m_transforms.size() != binding.skeleton_size() )
		m_transforms.resize( binding.skeleton_size() );
	for ( uint32 n = 0; n < node_data->size(); ++n )
	{
		const data_channel_set* node = ( *node_data )[n];
		sint16 bone_id = binding.m_indices[n];
		if ( bone_id >= 0 )
		{
			
			transform tr = node->size() > 0 ? raw_channel_interpolator( node, binding.m_key ).get< transform >( frame ) : transform( /*node->get_transform()*/ ); int confirm_that_not_needed;
			m_transforms[bone_id] = nv::interpolate( m_transforms[bone_id], tr, blend );
		}
	}
}

void nv::skeleton_transforms::delocalize_rec( const data_node_tree& node_data, const skeleton_binding& binding, uint32 id, const transform& parent )
{
	sint16 bone_id = binding.m_indices[id];
	transform global_mat = parent;
	if ( bone_id >= 0 )
	{
		global_mat *= m_transforms[bone_id];
		m_transforms[bone_id] = global_mat;
	}
	for ( auto child : node_data.children( id ) )
	{
		delocalize_rec( node_data, binding, child, global_mat );
	}
}

void nv::skeleton_transforms::animate_rec( const mesh_nodes_data* node_data, const skeleton_binding& binding, float frame, uint32 id, const transform& parent, bool local )
{
	const data_channel_set* node = ( *node_data )[id];
	transform node_mat;

	if ( node->size() > 0 )
		node_mat = raw_channel_interpolator( node, binding.m_key ).get< transform >( frame );
	int confirm_that_not_needed;
	// 	else
// 		node_mat = transform( node->get_transform() );
	sint16 bone_id = binding.m_indices[id];
	transform global_mat = parent * node_mat;
	if ( bone_id >= 0 )
	{
		m_transforms[bone_id] = local ? node_mat : global_mat;
	}
	for ( auto child : node_data->children( id ) )
	{
		animate_rec( node_data, binding, frame, child, global_mat, local );
	}
}

void nv::skeleton_transforms::blend_rec( const mesh_nodes_data* node_data, const skeleton_binding& binding, float frame, uint32 id, const transform& parent, bool local, float blend )
{
	const data_channel_set* node = ( *node_data )[id];
	int confirm_that_not_needed;
	transform node_mat/*( node->get_transform() )*/;

	if ( node->size() > 0 )
	{
		raw_channel_interpolator interpolator( node, binding.m_key );
		node_mat = interpolator.get< transform >( frame );
	}
	sint16 bone_id = binding.m_indices[id];
	transform global_mat = parent * node_mat;
	if ( bone_id >= 0 )
	{
		m_transforms[bone_id] = nv::interpolate( m_transforms[bone_id], local ? node_mat : global_mat, blend );
	}
	for ( auto child : node_data->children( id ) )
	{
		blend_rec( node_data, binding, frame, child, global_mat, local, blend );
	}
}


void nv::bone_transforms::prepare( const data_node_list& bone_data )
{
	m_offsets.resize( bone_data.size() );

	for ( nv::uint16 bi = 0; bi < bone_data.size(); ++bi )
		m_offsets[bi] = bone_data[bi].transform;
}