/*
 * ***** 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 *****
 * Simple deformation controller that restores a mesh to its rest position
 */

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

#ifdef _MSC_VER
  /* This warning tells us about truncation of __long__ stl-generated names.
   * It can occasionally cause DevStudio to have internal compiler warnings. */
#  pragma warning( disable:4786 )
#endif

#include "RAS_IPolygonMaterial.h"
#include "BL_DeformableGameObject.h"
#include "BL_MeshDeformer.h"
#include "RAS_MeshObject.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"

#include "CTR_Map.h"
#include "STR_HashedString.h"
#include "BLI_math.h"

bool BL_MeshDeformer::Apply(RAS_IPolyMaterial*)
{
	size_t i;

	// only apply once per frame if the mesh is actually modified
	if (m_pMeshObject->MeshModified() &&
	    m_lastDeformUpdate != m_gameobj->GetLastFrame())
	{
		// For each material
		for (list<RAS_MeshMaterial>::iterator mit= m_pMeshObject->GetFirstMaterial();
			mit != m_pMeshObject->GetLastMaterial(); ++ mit) {
			if (!mit->m_slots[(void*)m_gameobj])
				continue;

			RAS_MeshSlot *slot = *mit->m_slots[(void*)m_gameobj];
			RAS_MeshSlot::iterator it;

			// for each array
			for (slot->begin(it); !slot->end(it); slot->next(it)) {
				//	For each vertex
				for (i=it.startvertex; i<it.endvertex; i++) {
					RAS_TexVert& v = it.vertex[i];
					v.SetXYZ(m_bmesh->mvert[v.getOrigIndex()].co);
				}
			}
		}

		m_lastDeformUpdate = m_gameobj->GetLastFrame();

		return true;
	}

	return false;
}

BL_MeshDeformer::~BL_MeshDeformer()
{
	if (m_transverts)
		delete [] m_transverts;
	if (m_transnors)
		delete [] m_transnors;
}
 
void BL_MeshDeformer::ProcessReplica()
{
	m_transverts = NULL;
	m_transnors = NULL;
	m_tvtot = 0;
	m_bDynamic=false;
	m_lastDeformUpdate = -1;
}

void BL_MeshDeformer::Relink(CTR_Map<class CTR_HashedPtr, void*>*map)
{
	void **h_obj = (*map)[m_gameobj];

	if (h_obj)
		m_gameobj = (BL_DeformableGameObject*)(*h_obj);
	else
		m_gameobj = NULL;
}

/**
 * \warning This function is expensive!
 */
void BL_MeshDeformer::RecalcNormals()
{
	/* We don't normalize for performance, not doing it for faces normals
	 * gives area-weight normals which often look better anyway, and use
	 * GL_NORMALIZE so we don't have to do per vertex normalization either
	 * since the GPU can do it faster */
	list<RAS_MeshMaterial>::iterator mit;
	RAS_MeshSlot::iterator it;
	size_t i;

	/* set vertex normals to zero */
	memset(m_transnors, 0, sizeof(float)*3*m_bmesh->totvert);

	/* add face normals to vertices. */
	for (mit = m_pMeshObject->GetFirstMaterial();
		mit != m_pMeshObject->GetLastMaterial(); ++ mit) {
		if (!mit->m_slots[(void*)m_gameobj])
			continue;

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

		for (slot->begin(it); !slot->end(it); slot->next(it)) {
			int nvert = (int)it.array->m_type;

			for (i=0; i<it.totindex; i+=nvert) {
				RAS_TexVert& v1 = it.vertex[it.index[i]];
				RAS_TexVert& v2 = it.vertex[it.index[i+1]];
				RAS_TexVert& v3 = it.vertex[it.index[i+2]];
				RAS_TexVert *v4 = NULL;

				const float *co1 = m_transverts[v1.getOrigIndex()];
				const float *co2 = m_transverts[v2.getOrigIndex()];
				const float *co3 = m_transverts[v3.getOrigIndex()];
				const float *co4 = NULL;
				
				/* compute face normal */
				float fnor[3], n1[3], n2[3];

				if (nvert == 4) {
					v4 = &it.vertex[it.index[i+3]];
					co4 = m_transverts[v4->getOrigIndex()];

					n1[0] = co1[0] - co3[0];
					n1[1] = co1[1] - co3[1];
					n1[2] = co1[2] - co3[2];

					n2[0] = co2[0] - co4[0];
					n2[1] = co2[1] - co4[1];
					n2[2] = co2[2] - co4[2];
				}
				else {
					n1[0] = co1[0] - co2[0];
					n2[0] = co2[0] - co3[0];
					n1[1] = co1[1] - co2[1];

					n2[1] = co2[1] - co3[1];
					n1[2] = co1[2] - co2[2];
					n2[2] = co2[2] - co3[2];
				}

				fnor[0] = n1[1] * n2[2] - n1[2] * n2[1];
				fnor[1] = n1[2] * n2[0] - n1[0] * n2[2];
				fnor[2] = n1[0] * n2[1] - n1[1] * n2[0];
				normalize_v3(fnor);

				/* add to vertices for smooth normals */
				float *vn1 = m_transnors[v1.getOrigIndex()];
				float *vn2 = m_transnors[v2.getOrigIndex()];
				float *vn3 = m_transnors[v3.getOrigIndex()];

				vn1[0] += fnor[0]; vn1[1] += fnor[1]; vn1[2] += fnor[2];
				vn2[0] += fnor[0]; vn2[1] += fnor[1]; vn2[2] += fnor[2];
				vn3[0] += fnor[0]; vn3[1] += fnor[1]; vn3[2] += fnor[2];

				if (v4) {
					float *vn4 = m_transnors[v4->getOrigIndex()];
					vn4[0] += fnor[0]; vn4[1] += fnor[1]; vn4[2] += fnor[2];
				}

				/* in case of flat - just assign, the vertices are split */
				if (v1.getFlag() & RAS_TexVert::FLAT) {
					v1.SetNormal(fnor);
					v2.SetNormal(fnor);
					v3.SetNormal(fnor);
					if (v4)
						v4->SetNormal(fnor);
				}
			}
		}
	}

	/* assign smooth vertex normals */
	for (mit = m_pMeshObject->GetFirstMaterial();
		mit != m_pMeshObject->GetLastMaterial(); ++ mit) {
		if (!mit->m_slots[(void*)m_gameobj])
			continue;

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

		for (slot->begin(it); !slot->end(it); slot->next(it)) {
			for (i=it.startvertex; i<it.endvertex; i++) {
				RAS_TexVert& v = it.vertex[i];

				if (!(v.getFlag() & RAS_TexVert::FLAT))
					v.SetNormal(m_transnors[v.getOrigIndex()]); //.safe_normalized()
			}
		}
	}
}

void BL_MeshDeformer::VerifyStorage()
{
	/* Ensure that we have the right number of verts assigned */
	if (m_tvtot!=m_bmesh->totvert) {
		if (m_transverts)
			delete [] m_transverts;
		if (m_transnors)
			delete [] m_transnors;
		
		m_transverts=new float[m_bmesh->totvert][3];
		m_transnors=new float[m_bmesh->totvert][3];
		m_tvtot = m_bmesh->totvert;
	}
}