/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file gameengine/Converter/BL_SkinDeformer.cpp
 *  \ingroup bgeconv
 */

#ifdef _MSC_VER
#  pragma warning (disable:4786)
#endif

// Eigen3 stuff used for BGEDeformVerts
#include <Eigen/Core>
#include <Eigen/LU>

#include "BL_SkinDeformer.h"
#include "CTR_Map.h"
#include "STR_HashedString.h"
#include "RAS_IPolygonMaterial.h"
#include "RAS_MeshObject.h"

//#include "BL_ArmatureController.h"
#include "DNA_armature_types.h"
#include "DNA_action_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_modifier_types.h"
#include "BLI_utildefines.h"
#include "BKE_armature.h"
#include "BKE_action.h"
#include "MT_Point3.h"

extern "C"{
	#include "BKE_lattice.h"
	#include "BKE_deform.h"
}
 

#include "BLI_blenlib.h"
#include "BLI_math.h"

#define __NLA_DEFNORMALS
//#undef __NLA_DEFNORMALS

static short get_deformflags(struct Object *bmeshobj)
{
	short flags = ARM_DEF_VGROUP;

	ModifierData *md;
	for (md = (ModifierData *)bmeshobj->modifiers.first; md; md = md->next)
	{
		if (md->type == eModifierType_Armature)
		{
			flags |= ((ArmatureModifierData*)md)->deformflag;
			break;
		}
	}

	return flags;
}

BL_SkinDeformer::BL_SkinDeformer(BL_DeformableGameObject *gameobj,
                                 struct Object *bmeshobj,
                                 class RAS_MeshObject *mesh,
                                 BL_ArmatureObject* arma)
							:	//
							BL_MeshDeformer(gameobj, bmeshobj, mesh),
							m_armobj(arma),
							m_lastArmaUpdate(-1),
							//m_defbase(&bmeshobj->defbase),
							m_releaseobject(false),
							m_poseApplied(false),
							m_recalcNormal(true),
							m_copyNormals(false),
							m_dfnrToPC(NULL)
{
	copy_m4_m4(m_obmat, bmeshobj->obmat);
	m_deformflags = get_deformflags(bmeshobj);
};

BL_SkinDeformer::BL_SkinDeformer(
	BL_DeformableGameObject *gameobj,
	struct Object *bmeshobj_old,	// Blender object that owns the new mesh
	struct Object *bmeshobj_new,	// Blender object that owns the original mesh
	class RAS_MeshObject *mesh,
	bool release_object,
	bool recalc_normal,
	BL_ArmatureObject* arma)	:
		BL_MeshDeformer(gameobj, bmeshobj_old, mesh),
		m_armobj(arma),
		m_lastArmaUpdate(-1),
		//m_defbase(&bmeshobj_old->defbase),
		m_releaseobject(release_object),
		m_recalcNormal(recalc_normal),
		m_copyNormals(false),
		m_dfnrToPC(NULL)
	{
		// this is needed to ensure correct deformation of mesh:
		// the deformation is done with Blender's armature_deform_verts() function
		// that takes an object as parameter and not a mesh. The object matrice is used
		// in the calculation, so we must use the matrix of the original object to
		// simulate a pure replacement of the mesh.
		copy_m4_m4(m_obmat, bmeshobj_new->obmat);
		m_deformflags = get_deformflags(bmeshobj_new);
	}

BL_SkinDeformer::~BL_SkinDeformer()
{
	if (m_releaseobject && m_armobj)
		m_armobj->Release();
	if (m_dfnrToPC)
		delete [] m_dfnrToPC;
}

void BL_SkinDeformer::Relink(CTR_Map<class CTR_HashedPtr, void*>*map)
{
	if (m_armobj) {
		void **h_obj = (*map)[m_armobj];

		if (h_obj)
			m_armobj = (BL_ArmatureObject*)(*h_obj);
		else
			m_armobj=NULL;
	}

	BL_MeshDeformer::Relink(map);
}

bool BL_SkinDeformer::Apply(RAS_IPolyMaterial *mat)
{
	// We do everything in UpdateInternal() now so we can thread it.
	// All that is left is telling the rasterizer if we've changed the mesh
	bool retval = !m_poseApplied;
	m_poseApplied = true;
	return retval;
}

RAS_Deformer *BL_SkinDeformer::GetReplica()
{
	BL_SkinDeformer *result;

	result = new BL_SkinDeformer(*this);
	/* there is m_armobj that must be fixed but we cannot do it now, it will be done in Relink */
	result->ProcessReplica();
	return result;
}

void BL_SkinDeformer::ProcessReplica()
{
	BL_MeshDeformer::ProcessReplica();
	m_lastArmaUpdate = -1;
	m_releaseobject = false;
	m_dfnrToPC = NULL;
}

void BL_SkinDeformer::BlenderDeformVerts()
{
	float obmat[4][4];	// the original object matrix
	Object* par_arma = m_armobj->GetArmatureObject();

	// save matrix first
	copy_m4_m4(obmat, m_objMesh->obmat);
	// set reference matrix
	copy_m4_m4(m_objMesh->obmat, m_obmat);

	armature_deform_verts( par_arma, m_objMesh, NULL, m_transverts, NULL, m_bmesh->totvert, m_deformflags, NULL, NULL );
		
	// restore matrix 
	copy_m4_m4(m_objMesh->obmat, obmat);

#ifdef __NLA_DEFNORMALS
		if (m_recalcNormal)
			RecalcNormals();
#endif
}

void BL_SkinDeformer::BGEDeformVerts()
{
	Object *par_arma = m_armobj->GetArmatureObject();
	MDeformVert *dverts = m_bmesh->dvert;
	bDeformGroup *dg;
	int defbase_tot;
	Eigen::Matrix4f pre_mat, post_mat, chan_mat, norm_chan_mat;

	if (!dverts)
		return;

	defbase_tot = BLI_listbase_count(&m_objMesh->defbase);

	if (m_dfnrToPC == NULL)
	{
		m_dfnrToPC = new bPoseChannel*[defbase_tot];
		int i;
		for (i=0, dg=(bDeformGroup*)m_objMesh->defbase.first;
			dg;
			++i, dg = dg->next)
		{
			m_dfnrToPC[i] = BKE_pose_channel_find_name(par_arma->pose, dg->name);

			if (m_dfnrToPC[i] && m_dfnrToPC[i]->bone->flag & BONE_NO_DEFORM)
				m_dfnrToPC[i] = NULL;
		}
	}

	post_mat = Eigen::Matrix4f::Map((float*)m_obmat).inverse() * Eigen::Matrix4f::Map((float*)m_armobj->GetArmatureObject()->obmat);
	pre_mat = post_mat.inverse();

	MDeformVert *dv= dverts;
	MDeformWeight *dw;

	for (int i=0; i<m_bmesh->totvert; ++i, dv++)
	{
		float contrib = 0.f, weight, max_weight=-1.f;
		bPoseChannel *pchan=NULL;
		Eigen::Map<Eigen::Vector3f> norm = Eigen::Vector3f::Map(m_transnors[i]);
		Eigen::Vector4f vec(0, 0, 0, 1);
		Eigen::Vector4f co(m_transverts[i][0],
							m_transverts[i][1],
							m_transverts[i][2],
							1.f);

		if (!dv->totweight)
			continue;

		co = pre_mat * co;

		dw= dv->dw;

		for (unsigned int j= dv->totweight; j != 0; j--, dw++)
		{
			const int index = dw->def_nr;

			if (index < defbase_tot && (pchan=m_dfnrToPC[index]))
			{
				weight = dw->weight;

				if (weight)
				{
					chan_mat = Eigen::Matrix4f::Map((float*)pchan->chan_mat);

					// Update Vertex Position
					vec.noalias() += (chan_mat*co - co)*weight;

					// Save the most influential channel so we can use it to update the vertex normal
					if (weight > max_weight)
					{
						max_weight = weight;
						norm_chan_mat = chan_mat;
					}

					contrib += weight;
				}
			}
		}
		
		// Update Vertex Normal
		norm = norm_chan_mat.topLeftCorner<3, 3>()*norm;

		co.noalias() += vec/contrib;
		co[3] = 1.f; // Make sure we have a 1 for the w component!

		co = post_mat * co;

		m_transverts[i][0] = co[0];
		m_transverts[i][1] = co[1];
		m_transverts[i][2] = co[2];
	}
	m_copyNormals = true;
}

void BL_SkinDeformer::UpdateTransverts()
{
	RAS_MeshSlot::iterator it;
	RAS_MeshMaterial *mmat;
	RAS_MeshSlot *slot;
	size_t i, nmat, imat;

	if (m_transverts) {
		// the vertex cache is unique to this deformer, no need to update it
		// if it wasn't updated! We must update all the materials at once
		// because we will not get here again for the other material
		nmat = m_pMeshObject->NumMaterials();
		for (imat=0; imat<nmat; imat++) {
			mmat = m_pMeshObject->GetMeshMaterial(imat);
			if (!mmat->m_slots[(void*)m_gameobj])
				continue;

			slot = *mmat->m_slots[(void*)m_gameobj];

			// for each array
			for (slot->begin(it); !slot->end(it); slot->next(it)) {
				// for each vertex
				// copy the untransformed data from the original mvert
				for (i=it.startvertex; i<it.endvertex; i++) {
					RAS_TexVert& v = it.vertex[i];
					v.SetXYZ(m_transverts[v.getOrigIndex()]);
					if (m_copyNormals)
						v.SetNormal(m_transnors[v.getOrigIndex()]);
				}
			}
		}

		if (m_copyNormals)
			m_copyNormals = false;
	}
}

bool BL_SkinDeformer::UpdateInternal(bool shape_applied)
{
	/* See if the armature has been updated for this frame */
	if (PoseUpdated()) {

		if (!shape_applied) {
			/* store verts locally */
			VerifyStorage();

			/* duplicate */
			for (int v =0; v<m_bmesh->totvert; v++)
			{
				copy_v3_v3(m_transverts[v], m_bmesh->mvert[v].co);
				normal_short_to_float_v3(m_transnors[v], m_bmesh->mvert[v].no);
			}
		}

		m_armobj->ApplyPose();

		if (m_armobj->GetVertDeformType() == ARM_VDEF_BGE_CPU)
			BGEDeformVerts();
		else
			BlenderDeformVerts();

		/* Update the current frame */
		m_lastArmaUpdate=m_armobj->GetLastFrame();

		m_armobj->RestorePose();
		/* dynamic vertex, cannot use display list */
		m_bDynamic = true;

		UpdateTransverts();

		m_poseApplied = false;

		/* indicate that the m_transverts and normals are up to date */
		return true;
	}

	return false;
}

bool BL_SkinDeformer::Update(void)
{
	return UpdateInternal(false);
}

/* XXX note: I propose to drop this function */
void BL_SkinDeformer::SetArmature(BL_ArmatureObject *armobj)
{
	// only used to set the object now
	m_armobj = armobj;
}