/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
Copyright (C) 2006-2011 Robert Beckebans <trebor_7@users.sourceforge.net>

This file is part of Daemon source code.

Daemon source code 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.

Daemon source code 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 Daemon source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// tr_model_md5.c -- Doom 3 .md5mesh model loading and caching

#include "tr_local.h"
#include "tr_model_skel.h"

/*
=================
R_LoadMD5
=================
*/
qboolean R_LoadMD5( model_t *mod, void *buffer, int bufferSize, const char *modName )
{
	int           i, j, k;
	md5Model_t    *md5;
	md5Bone_t     *bone;
	md5Surface_t  *surf;
	srfTriangle_t *tri;
	md5Vertex_t   *v;
	md5Weight_t   *weight;
	int           version;
	shader_t      *sh;
	char          *buf_p;
	char          *token;
	vec3_t        boneOrigin;
	quat_t        boneQuat;
	matrix_t      boneMat;

	int           numRemaining;
	growList_t    sortedTriangles;
	growList_t    vboTriangles;
	growList_t    vboSurfaces;

	int           numBoneReferences;
	int           boneReferences[ MAX_BONES ];

	buf_p = ( char * ) buffer;

	// skip MD5Version indent string
	COM_ParseExt2( &buf_p, qfalse );

	// check version
	token = COM_ParseExt2( &buf_p, qfalse );
	version = atoi( token );

	if ( version != MD5_VERSION )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: %s has wrong version (%i should be %i)\n", modName, version, MD5_VERSION );
		return qfalse;
	}

	mod->type = MOD_MD5;
	mod->dataSize += sizeof( md5Model_t );
	md5 = mod->md5 = ri.Hunk_Alloc( sizeof( md5Model_t ), h_low );

	// skip commandline <arguments string>
	token = COM_ParseExt2( &buf_p, qtrue );
	token = COM_ParseExt2( &buf_p, qtrue );
//  ri.Printf(PRINT_ALL, "%s\n", token);

	// parse numJoints <number>
	token = COM_ParseExt2( &buf_p, qtrue );

	if ( Q_stricmp( token, "numJoints" ) )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'numJoints' found '%s' in model '%s'\n", token, modName );
		return qfalse;
	}

	token = COM_ParseExt2( &buf_p, qfalse );
	md5->numBones = atoi( token );

	// parse numMeshes <number>
	token = COM_ParseExt2( &buf_p, qtrue );

	if ( Q_stricmp( token, "numMeshes" ) )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'numMeshes' found '%s' in model '%s'\n", token, modName );
		return qfalse;
	}

	token = COM_ParseExt2( &buf_p, qfalse );
	md5->numSurfaces = atoi( token );
	//ri.Printf(PRINT_ALL, "R_LoadMD5: '%s' has %i surfaces\n", modName, md5->numSurfaces);

	if ( md5->numBones < 1 )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: '%s' has no bones\n", modName );
		return qfalse;
	}

	if ( md5->numBones > MAX_BONES )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: '%s' has more than %i bones (%i)\n", modName, MAX_BONES, md5->numBones );
		return qfalse;
	}

	//ri.Printf(PRINT_ALL, "R_LoadMD5: '%s' has %i bones\n", modName, md5->numBones);

	// parse all the bones
	md5->bones = ri.Hunk_Alloc( sizeof( *bone ) * md5->numBones, h_low );

	// parse joints {
	token = COM_ParseExt2( &buf_p, qtrue );

	if ( Q_stricmp( token, "joints" ) )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'joints' found '%s' in model '%s'\n", token, modName );
		return qfalse;
	}

	token = COM_ParseExt2( &buf_p, qfalse );

	if ( Q_stricmp( token, "{" ) )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '{' found '%s' in model '%s'\n", token, modName );
		return qfalse;
	}

	for ( i = 0, bone = md5->bones; i < md5->numBones; i++, bone++ )
	{
		token = COM_ParseExt2( &buf_p, qtrue );
		Q_strncpyz( bone->name, token, sizeof( bone->name ) );

		//ri.Printf(PRINT_ALL, "R_LoadMD5: '%s' has bone '%s'\n", modName, bone->name);

		token = COM_ParseExt2( &buf_p, qfalse );
		bone->parentIndex = atoi( token );

		//ri.Printf(PRINT_ALL, "R_LoadMD5: '%s' has bone '%s' with parent index %i\n", modName, bone->name, bone->parentIndex);

		if ( bone->parentIndex >= md5->numBones )
		{
			ri.Error( ERR_DROP, "R_LoadMD5: '%s' has bone '%s' with bad parent index %i while numBones is %i", modName,
			          bone->name, bone->parentIndex, md5->numBones );
		}

		// skip (
		token = COM_ParseExt2( &buf_p, qfalse );

		if ( Q_stricmp( token, "(" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '(' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		for ( j = 0; j < 3; j++ )
		{
			token = COM_ParseExt2( &buf_p, qfalse );
			boneOrigin[ j ] = atof( token );
		}

		// skip )
		token = COM_ParseExt2( &buf_p, qfalse );

		if ( Q_stricmp( token, ")" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected ')' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		// skip (
		token = COM_ParseExt2( &buf_p, qfalse );

		if ( Q_stricmp( token, "(" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '(' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		for ( j = 0; j < 3; j++ )
		{
			token = COM_ParseExt2( &buf_p, qfalse );
			boneQuat[ j ] = atof( token );
		}

		QuatCalcW( boneQuat );
		MatrixFromQuat( boneMat, boneQuat );

		VectorCopy( boneOrigin, bone->origin );
		QuatCopy( boneQuat, bone->rotation );

		MatrixSetupTransformFromQuat( bone->inverseTransform, boneQuat, boneOrigin );
		MatrixInverse( bone->inverseTransform );

		// skip )
		token = COM_ParseExt2( &buf_p, qfalse );

		if ( Q_stricmp( token, ")" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '(' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}
	}

	// parse }
	token = COM_ParseExt2( &buf_p, qtrue );

	if ( Q_stricmp( token, "}" ) )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '}' found '%s' in model '%s'\n", token, modName );
		return qfalse;
	}

	// parse all the surfaces
	if ( md5->numSurfaces < 1 )
	{
		ri.Printf( PRINT_WARNING, "R_LoadMD5: '%s' has no surfaces\n", modName );
		return qfalse;
	}

	//ri.Printf(PRINT_ALL, "R_LoadMD5: '%s' has %i surfaces\n", modName, md5->numSurfaces);

	md5->surfaces = ri.Hunk_Alloc( sizeof( *surf ) * md5->numSurfaces, h_low );

	for ( i = 0, surf = md5->surfaces; i < md5->numSurfaces; i++, surf++ )
	{
		// parse mesh {
		token = COM_ParseExt2( &buf_p, qtrue );

		if ( Q_stricmp( token, "mesh" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'mesh' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		token = COM_ParseExt2( &buf_p, qfalse );

		if ( Q_stricmp( token, "{" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '{' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		// change to surface identifier
		surf->surfaceType = SF_MD5;

		// give pointer to model for Tess_SurfaceMD5
		surf->model = md5;

		// parse shader <name>
		token = COM_ParseExt2( &buf_p, qtrue );

		if ( Q_stricmp( token, "shader" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'shader' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		token = COM_ParseExt2( &buf_p, qfalse );
		Q_strncpyz( surf->shader, token, sizeof( surf->shader ) );

		//ri.Printf(PRINT_ALL, "R_LoadMD5: '%s' uses shader '%s'\n", modName, surf->shader);

		// FIXME .md5mesh meshes don't have surface names
		// lowercase the surface name so skin compares are faster
		//Q_strlwr(surf->name);
		//ri.Printf(PRINT_ALL, "R_LoadMD5: '%s' has surface '%s'\n", modName, surf->name);

		// register the shaders
		sh = R_FindShader( surf->shader, SHADER_3D_DYNAMIC, RSF_DEFAULT );

		if ( sh->defaultShader )
		{
			surf->shaderIndex = 0;
		}
		else
		{
			surf->shaderIndex = sh->index;
		}

		// parse numVerts <number>
		token = COM_ParseExt2( &buf_p, qtrue );

		if ( Q_stricmp( token, "numVerts" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'numVerts' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		token = COM_ParseExt2( &buf_p, qfalse );
		surf->numVerts = atoi( token );

		if ( surf->numVerts > SHADER_MAX_VERTEXES )
		{
			ri.Error( ERR_DROP, "R_LoadMD5: '%s' has more than %i verts on a surface (%i)",
			          modName, SHADER_MAX_VERTEXES, surf->numVerts );
		}

		surf->verts = ri.Hunk_Alloc( sizeof( *v ) * surf->numVerts, h_low );

		for ( j = 0, v = surf->verts; j < surf->numVerts; j++, v++ )
		{
			// skip vert <number>
			token = COM_ParseExt2( &buf_p, qtrue );

			if ( Q_stricmp( token, "vert" ) )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'vert' found '%s' in model '%s'\n", token, modName );
				return qfalse;
			}

			COM_ParseExt2( &buf_p, qfalse );

			// skip (
			token = COM_ParseExt2( &buf_p, qfalse );

			if ( Q_stricmp( token, "(" ) )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '(' found '%s' in model '%s'\n", token, modName );
				return qfalse;
			}

			for ( k = 0; k < 2; k++ )
			{
				token = COM_ParseExt2( &buf_p, qfalse );
				v->texCoords[ k ] = atof( token );
			}

			// skip )
			token = COM_ParseExt2( &buf_p, qfalse );

			if ( Q_stricmp( token, ")" ) )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: expected ')' found '%s' in model '%s'\n", token, modName );
				return qfalse;
			}

			token = COM_ParseExt2( &buf_p, qfalse );
			v->firstWeight = atoi( token );

			token = COM_ParseExt2( &buf_p, qfalse );
			v->numWeights = atoi( token );

			if ( v->numWeights > MAX_WEIGHTS )
			{
				ri.Error( ERR_DROP, "R_LoadMD5: vertex %i requires more than %i weights on surface (%i) in model '%s'",
				          j, MAX_WEIGHTS, i, modName );
			}
		}

		// parse numTris <number>
		token = COM_ParseExt2( &buf_p, qtrue );

		if ( Q_stricmp( token, "numTris" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'numTris' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		token = COM_ParseExt2( &buf_p, qfalse );
		surf->numTriangles = atoi( token );

		if ( surf->numTriangles > SHADER_MAX_TRIANGLES )
		{
			ri.Error( ERR_DROP, "R_LoadMD5: '%s' has more than %i triangles on a surface (%i)",
			          modName, SHADER_MAX_TRIANGLES, surf->numTriangles );
		}

		surf->triangles = ri.Hunk_Alloc( sizeof( *tri ) * surf->numTriangles, h_low );

		for ( j = 0, tri = surf->triangles; j < surf->numTriangles; j++, tri++ )
		{
			// skip tri <number>
			token = COM_ParseExt2( &buf_p, qtrue );

			if ( Q_stricmp( token, "tri" ) )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'tri' found '%s' in model '%s'\n", token, modName );
				return qfalse;
			}

			COM_ParseExt2( &buf_p, qfalse );

			for ( k = 0; k < 3; k++ )
			{
				token = COM_ParseExt2( &buf_p, qfalse );
				tri->indexes[ k ] = atoi( token );
			}
		}

		// parse numWeights <number>
		token = COM_ParseExt2( &buf_p, qtrue );

		if ( Q_stricmp( token, "numWeights" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'numWeights' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		token = COM_ParseExt2( &buf_p, qfalse );
		surf->numWeights = atoi( token );

		surf->weights = ri.Hunk_Alloc( sizeof( *weight ) * surf->numWeights, h_low );

		for ( j = 0, weight = surf->weights; j < surf->numWeights; j++, weight++ )
		{
			// skip weight <number>
			token = COM_ParseExt2( &buf_p, qtrue );

			if ( Q_stricmp( token, "weight" ) )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: expected 'weight' found '%s' in model '%s'\n", token, modName );
				return qfalse;
			}

			COM_ParseExt2( &buf_p, qfalse );

			token = COM_ParseExt2( &buf_p, qfalse );
			weight->boneIndex = atoi( token );

			token = COM_ParseExt2( &buf_p, qfalse );
			weight->boneWeight = atof( token );

			// skip (
			token = COM_ParseExt2( &buf_p, qfalse );

			if ( Q_stricmp( token, "(" ) )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '(' found '%s' in model '%s'\n", token, modName );
				return qfalse;
			}

			for ( k = 0; k < 3; k++ )
			{
				token = COM_ParseExt2( &buf_p, qfalse );
				weight->offset[ k ] = atof( token );
			}

			// skip )
			token = COM_ParseExt2( &buf_p, qfalse );

			if ( Q_stricmp( token, ")" ) )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: expected ')' found '%s' in model '%s'\n", token, modName );
				return qfalse;
			}
		}

		// parse }
		token = COM_ParseExt2( &buf_p, qtrue );

		if ( Q_stricmp( token, "}" ) )
		{
			ri.Printf( PRINT_WARNING, "R_LoadMD5: expected '}' found '%s' in model '%s'\n", token, modName );
			return qfalse;
		}

		// loop trough all vertices and set up the vertex weights
		for ( j = 0, v = surf->verts; j < surf->numVerts; j++, v++ )
		{
			v->weights = ri.Hunk_Alloc( sizeof( *v->weights ) * v->numWeights, h_low );

			for ( k = 0; k < v->numWeights; k++ )
			{
				v->weights[ k ] = surf->weights + ( v->firstWeight + k );
			}
		}
	}

	// loading is done now calculate the bounding box and tangent spaces
	ClearBounds( md5->bounds[ 0 ], md5->bounds[ 1 ] );

	for ( i = 0, surf = md5->surfaces; i < md5->numSurfaces; i++, surf++ )
	{
		for ( j = 0, v = surf->verts; j < surf->numVerts; j++, v++ )
		{
			vec3_t      tmpVert;
			md5Weight_t *w;

			VectorClear( tmpVert );

			for ( k = 0, w = v->weights[ 0 ]; k < v->numWeights; k++, w++ )
			{
				vec3_t offsetVec;

				bone = &md5->bones[ w->boneIndex ];

				QuatTransformVector( bone->rotation, w->offset, offsetVec );
				VectorAdd( bone->origin, offsetVec, offsetVec );

				VectorMA( tmpVert, w->boneWeight, offsetVec, tmpVert );
			}

			VectorCopy( tmpVert, v->position );
			AddPointToBounds( tmpVert, md5->bounds[ 0 ], md5->bounds[ 1 ] );
		}

		// calc tangent spaces
#if 1
		{
			const float *v0, *v1, *v2;
			const float *t0, *t1, *t2;
			vec3_t      tangent;
			vec3_t      binormal;
			vec3_t      normal;

			for ( j = 0, v = surf->verts; j < surf->numVerts; j++, v++ )
			{
				VectorClear( v->tangent );
				VectorClear( v->binormal );
				VectorClear( v->normal );
			}

			for ( j = 0, tri = surf->triangles; j < surf->numTriangles; j++, tri++ )
			{
				v0 = surf->verts[ tri->indexes[ 0 ] ].position;
				v1 = surf->verts[ tri->indexes[ 1 ] ].position;
				v2 = surf->verts[ tri->indexes[ 2 ] ].position;

				t0 = surf->verts[ tri->indexes[ 0 ] ].texCoords;
				t1 = surf->verts[ tri->indexes[ 1 ] ].texCoords;
				t2 = surf->verts[ tri->indexes[ 2 ] ].texCoords;

#if 1
				R_CalcTangentSpace( tangent, binormal, normal, v0, v1, v2, t0, t1, t2 );
#else
				R_CalcNormalForTriangle( normal, v0, v1, v2 );
				R_CalcTangentsForTriangle( tangent, binormal, v0, v1, v2, t0, t1, t2 );
#endif

				for ( k = 0; k < 3; k++ )
				{
					float *v;

					v = surf->verts[ tri->indexes[ k ] ].tangent;
					VectorAdd( v, tangent, v );

					v = surf->verts[ tri->indexes[ k ] ].binormal;
					VectorAdd( v, binormal, v );

					v = surf->verts[ tri->indexes[ k ] ].normal;
					VectorAdd( v, normal, v );
				}
			}

			for ( j = 0, v = surf->verts; j < surf->numVerts; j++, v++ )
			{
				VectorNormalize( v->tangent );
				VectorNormalize( v->binormal );
				VectorNormalize( v->normal );
			}
		}
#else
		{
			int         k;
			float       bb, s, t;
			vec3_t      bary;
			vec3_t      faceNormal;
			md5Vertex_t *dv[ 3 ];

			for ( j = 0, tri = surf->triangles; j < surf->numTriangles; j++, tri++ )
			{
				dv[ 0 ] = &surf->verts[ tri->indexes[ 0 ] ];
				dv[ 1 ] = &surf->verts[ tri->indexes[ 1 ] ];
				dv[ 2 ] = &surf->verts[ tri->indexes[ 2 ] ];

				R_CalcNormalForTriangle( faceNormal, dv[ 0 ]->position, dv[ 1 ]->position, dv[ 2 ]->position );

				// calculate barycentric basis for the triangle
				bb = ( dv[ 1 ]->texCoords[ 0 ] - dv[ 0 ]->texCoords[ 0 ] ) * ( dv[ 2 ]->texCoords[ 1 ] - dv[ 0 ]->texCoords[ 1 ] ) - ( dv[ 2 ]->texCoords[ 0 ] - dv[ 0 ]->texCoords[ 0 ] ) * ( dv[ 1 ]->texCoords[ 1 ] -
				     dv[ 0 ]->texCoords[ 1 ] );

				if ( fabs( bb ) < 0.00000001f )
				{
					continue;
				}

				// do each vertex
				for ( k = 0; k < 3; k++ )
				{
					// calculate s tangent vector
					s = dv[ k ]->texCoords[ 0 ] + 10.0f;
					t = dv[ k ]->texCoords[ 1 ];
					bary[ 0 ] = ( ( dv[ 1 ]->texCoords[ 0 ] - s ) * ( dv[ 2 ]->texCoords[ 1 ] - t ) - ( dv[ 2 ]->texCoords[ 0 ] - s ) * ( dv[ 1 ]->texCoords[ 1 ] - t ) ) / bb;
					bary[ 1 ] = ( ( dv[ 2 ]->texCoords[ 0 ] - s ) * ( dv[ 0 ]->texCoords[ 1 ] - t ) - ( dv[ 0 ]->texCoords[ 0 ] - s ) * ( dv[ 2 ]->texCoords[ 1 ] - t ) ) / bb;
					bary[ 2 ] = ( ( dv[ 0 ]->texCoords[ 0 ] - s ) * ( dv[ 1 ]->texCoords[ 1 ] - t ) - ( dv[ 1 ]->texCoords[ 0 ] - s ) * ( dv[ 0 ]->texCoords[ 1 ] - t ) ) / bb;

					dv[ k ]->tangent[ 0 ] = bary[ 0 ] * dv[ 0 ]->position[ 0 ] + bary[ 1 ] * dv[ 1 ]->position[ 0 ] + bary[ 2 ] * dv[ 2 ]->position[ 0 ];
					dv[ k ]->tangent[ 1 ] = bary[ 0 ] * dv[ 0 ]->position[ 1 ] + bary[ 1 ] * dv[ 1 ]->position[ 1 ] + bary[ 2 ] * dv[ 2 ]->position[ 1 ];
					dv[ k ]->tangent[ 2 ] = bary[ 0 ] * dv[ 0 ]->position[ 2 ] + bary[ 1 ] * dv[ 1 ]->position[ 2 ] + bary[ 2 ] * dv[ 2 ]->position[ 2 ];

					VectorSubtract( dv[ k ]->tangent, dv[ k ]->position, dv[ k ]->tangent );
					VectorNormalize( dv[ k ]->tangent );

					// calculate t tangent vector (binormal)
					s = dv[ k ]->texCoords[ 0 ];
					t = dv[ k ]->texCoords[ 1 ] + 10.0f;
					bary[ 0 ] = ( ( dv[ 1 ]->texCoords[ 0 ] - s ) * ( dv[ 2 ]->texCoords[ 1 ] - t ) - ( dv[ 2 ]->texCoords[ 0 ] - s ) * ( dv[ 1 ]->texCoords[ 1 ] - t ) ) / bb;
					bary[ 1 ] = ( ( dv[ 2 ]->texCoords[ 0 ] - s ) * ( dv[ 0 ]->texCoords[ 1 ] - t ) - ( dv[ 0 ]->texCoords[ 0 ] - s ) * ( dv[ 2 ]->texCoords[ 1 ] - t ) ) / bb;
					bary[ 2 ] = ( ( dv[ 0 ]->texCoords[ 0 ] - s ) * ( dv[ 1 ]->texCoords[ 1 ] - t ) - ( dv[ 1 ]->texCoords[ 0 ] - s ) * ( dv[ 0 ]->texCoords[ 1 ] - t ) ) / bb;

					dv[ k ]->binormal[ 0 ] = bary[ 0 ] * dv[ 0 ]->position[ 0 ] + bary[ 1 ] * dv[ 1 ]->position[ 0 ] + bary[ 2 ] * dv[ 2 ]->position[ 0 ];
					dv[ k ]->binormal[ 1 ] = bary[ 0 ] * dv[ 0 ]->position[ 1 ] + bary[ 1 ] * dv[ 1 ]->position[ 1 ] + bary[ 2 ] * dv[ 2 ]->position[ 1 ];
					dv[ k ]->binormal[ 2 ] = bary[ 0 ] * dv[ 0 ]->position[ 2 ] + bary[ 1 ] * dv[ 1 ]->position[ 2 ] + bary[ 2 ] * dv[ 2 ]->position[ 2 ];

					VectorSubtract( dv[ k ]->binormal, dv[ k ]->position, dv[ k ]->binormal );
					VectorNormalize( dv[ k ]->binormal );

					// calculate the normal as cross product N=TxB
#if 0
					CrossProduct( dv[ k ]->tangent, dv[ k ]->binormal, dv[ k ]->normal );
					VectorNormalize( dv[ k ]->normal );

					// Gram-Schmidt orthogonalization process for B
					// compute the cross product B=NxT to obtain
					// an orthogonal basis
					CrossProduct( dv[ k ]->normal, dv[ k ]->tangent, dv[ k ]->binormal );

					if ( DotProduct( dv[ k ]->normal, faceNormal ) < 0 )
					{
						VectorInverse( dv[ k ]->normal );
						//VectorInverse(dv[k]->tangent);
						//VectorInverse(dv[k]->binormal);
					}

#else
					VectorAdd( dv[ k ]->normal, faceNormal, dv[ k ]->normal );
#endif
				}
			}

#if 1

			for ( j = 0, v = surf->verts; j < surf->numVerts; j++, v++ )
			{
				//VectorNormalize(v->tangent);
				//VectorNormalize(v->binormal);
				VectorNormalize( v->normal );
			}

#endif
		}
#endif

#if 0

		// do another extra smoothing for normals to avoid flat shading
		for ( j = 0; j < surf->numVerts; j++ )
		{
			for ( k = 0; k < surf->numVerts; k++ )
			{
				if ( j == k )
				{
					continue;
				}

				if ( VectorCompare( surf->verts[ j ].position, surf->verts[ k ].position ) )
				{
					VectorAdd( surf->verts[ j ].normal, surf->verts[ k ].normal, surf->verts[ j ].normal );
				}
			}

			VectorNormalize( surf->verts[ j ].normal );
		}

#endif
	}

	// split the surfaces into VBO surfaces by the maximum number of GPU vertex skinning bones
	Com_InitGrowList( &vboSurfaces, 10 );

	for ( i = 0, surf = md5->surfaces; i < md5->numSurfaces; i++, surf++ )
	{
		// sort triangles
		Com_InitGrowList( &sortedTriangles, 1000 );

		for ( j = 0, tri = surf->triangles; j < surf->numTriangles; j++, tri++ )
		{
			skelTriangle_t *sortTri = Com_Allocate( sizeof( *sortTri ) );

			for ( k = 0; k < 3; k++ )
			{
				sortTri->indexes[ k ] = tri->indexes[ k ];
				sortTri->vertexes[ k ] = &surf->verts[ tri->indexes[ k ] ];
			}

			sortTri->referenced = qfalse;

			Com_AddToGrowList( &sortedTriangles, sortTri );
		}

		//qsort(sortedTriangles.elements, sortedTriangles.currentElements, sizeof(void *), CompareTrianglesByBoneReferences);

#if 0

		for ( j = 0; j < sortedTriangles.currentElements; j++ )
		{
			int            b[ MAX_WEIGHTS * 3 ];

			skelTriangle_t *sortTri = Com_GrowListElement( &sortedTriangles, j );

			for ( k = 0; k < 3; k++ )
			{
				v = sortTri->vertexes[ k ];

				for ( l = 0; l < MAX_WEIGHTS; l++ )
				{
					b[ k * 3 + l ] = ( l < v->numWeights ) ? v->weights[ l ]->boneIndex : 9999;
				}

				qsort( b, MAX_WEIGHTS * 3, sizeof( int ), CompareBoneIndices );
				//ri.Printf(PRINT_ALL, "bone indices: %i %i %i %i\n", b[k * 3 + 0], b[k * 3 + 1], b[k * 3 + 2], b[k * 3 + 3]);
			}
		}

#endif

		numRemaining = sortedTriangles.currentElements;

		while ( numRemaining )
		{
			numBoneReferences = 0;
			Com_Memset( boneReferences, 0, sizeof( boneReferences ) );

			Com_InitGrowList( &vboTriangles, 1000 );

			for ( j = 0; j < sortedTriangles.currentElements; j++ )
			{
				skelTriangle_t *sortTri = Com_GrowListElement( &sortedTriangles, j );

				if ( sortTri->referenced )
				{
					continue;
				}

				if ( AddTriangleToVBOTriangleList( &vboTriangles, sortTri, &numBoneReferences, boneReferences ) )
				{
					sortTri->referenced = qtrue;
				}
			}

			if ( !vboTriangles.currentElements )
			{
				ri.Printf( PRINT_WARNING, "R_LoadMD5: could not add triangles to a remaining VBO surfaces for model '%s'\n", modName );
				Com_DestroyGrowList( &vboTriangles );
				break;
			}

			AddSurfaceToVBOSurfacesList( &vboSurfaces, &vboTriangles, md5, surf, i, numBoneReferences, boneReferences );
			numRemaining -= vboTriangles.currentElements;

			Com_DestroyGrowList( &vboTriangles );
		}

		for ( j = 0; j < sortedTriangles.currentElements; j++ )
		{
			skelTriangle_t *sortTri = Com_GrowListElement( &sortedTriangles, j );

			Com_Dealloc( sortTri );
		}

		Com_DestroyGrowList( &sortedTriangles );
	}

	// move VBO surfaces list to hunk
	md5->numVBOSurfaces = vboSurfaces.currentElements;
	md5->vboSurfaces = ri.Hunk_Alloc( md5->numVBOSurfaces * sizeof( *md5->vboSurfaces ), h_low );

	for ( i = 0; i < md5->numVBOSurfaces; i++ )
	{
		md5->vboSurfaces[ i ] = ( srfVBOMD5Mesh_t * ) Com_GrowListElement( &vboSurfaces, i );
	}

	Com_DestroyGrowList( &vboSurfaces );

	return qtrue;
}
