ioef/code/renderer/tr_model_iqm.c

/*
===========================================================================
Copyright (C) 2011 Thilo Schulz <thilo@tjps.eu>
Copyright (C) 2011 Matthias Bentrup <matthias.bentrup@googlemail.com>

This file is part of Quake III Arena source code.

Quake III Arena 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.

Quake III Arena 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 Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/

#include "tr_local.h"

#define	LL(x) x=LittleLong(x)

static qboolean IQM_CheckRange( iqmHeader_t *header, int offset,
				int count,int size ) {
	// return true if the range specified by offset, count and size
	// doesn't fit into the file
	return ( count <= 0 ||
		 offset < 0 ||
		 offset > header->filesize ||
		 offset + count * size < 0 ||
		 offset + count * size > header->filesize );
}
// "multiply" 3x4 matrices, these are assumed to be the top 3 rows
// of a 4x4 matrix with the last row = (0 0 0 1)
static void Matrix34Multiply( float *a, float *b, float *out ) {
	out[ 0] = a[0] * b[0] + a[1] * b[4] + a[ 2] * b[ 8];
	out[ 1] = a[0] * b[1] + a[1] * b[5] + a[ 2] * b[ 9];
	out[ 2] = a[0] * b[2] + a[1] * b[6] + a[ 2] * b[10];
	out[ 3] = a[0] * b[3] + a[1] * b[7] + a[ 2] * b[11] + a[ 3];
	out[ 4] = a[4] * b[0] + a[5] * b[4] + a[ 6] * b[ 8];
	out[ 5] = a[4] * b[1] + a[5] * b[5] + a[ 6] * b[ 9];
	out[ 6] = a[4] * b[2] + a[5] * b[6] + a[ 6] * b[10];
	out[ 7] = a[4] * b[3] + a[5] * b[7] + a[ 6] * b[11] + a[ 7];
	out[ 8] = a[8] * b[0] + a[9] * b[4] + a[10] * b[ 8];
	out[ 9] = a[8] * b[1] + a[9] * b[5] + a[10] * b[ 9];
	out[10] = a[8] * b[2] + a[9] * b[6] + a[10] * b[10];
	out[11] = a[8] * b[3] + a[9] * b[7] + a[10] * b[11] + a[11];
}
static void InterpolateMatrix( float *a, float *b, float lerp, float *mat ) {
	float unLerp = 1.0f - lerp;

	mat[ 0] = a[ 0] * unLerp + b[ 0] * lerp;
	mat[ 1] = a[ 1] * unLerp + b[ 1] * lerp;
	mat[ 2] = a[ 2] * unLerp + b[ 2] * lerp;
	mat[ 3] = a[ 3] * unLerp + b[ 3] * lerp;
	mat[ 4] = a[ 4] * unLerp + b[ 4] * lerp;
	mat[ 5] = a[ 5] * unLerp + b[ 5] * lerp;
	mat[ 6] = a[ 6] * unLerp + b[ 6] * lerp;
	mat[ 7] = a[ 7] * unLerp + b[ 7] * lerp;
	mat[ 8] = a[ 8] * unLerp + b[ 8] * lerp;
	mat[ 9] = a[ 9] * unLerp + b[ 9] * lerp;
	mat[10] = a[10] * unLerp + b[10] * lerp;
	mat[11] = a[11] * unLerp + b[11] * lerp;
}

/*
=================
R_LoadIQM

Load an IQM model and compute the joint matrices for every frame.
=================
*/
qboolean R_LoadIQM( model_t *mod, void *buffer, int filesize, const char *mod_name ) {
	iqmHeader_t		*header;
	iqmVertexArray_t	*vertexarray;
	iqmTriangle_t		*triangle;
	iqmMesh_t		*mesh;
	iqmJoint_t		*joint;
	iqmPose_t		*pose;
	iqmBounds_t		*bounds;
	unsigned short		*framedata;
	char			*str;
	int			i, j;
	float			*jointMats, *mat;
	size_t			size, joint_names;
	iqmData_t		*iqmData;
	srfIQModel_t		*surface;

	if( filesize < sizeof(iqmHeader_t) ) {
		return qfalse;
	}

	header = (iqmHeader_t *)buffer;
	if( Q_strncmp( header->magic, IQM_MAGIC, sizeof(header->magic) ) ) {
		return qfalse;
	}

	LL( header->version );
	if( header->version != IQM_VERSION ) {
		return qfalse;
	}

	LL( header->filesize );
	if( header->filesize > filesize || header->filesize > 16<<20 ) {
		return qfalse;
	}

	LL( header->flags );
	LL( header->num_text );
	LL( header->ofs_text );
	LL( header->num_meshes );
	LL( header->ofs_meshes );
	LL( header->num_vertexarrays );
	LL( header->num_vertexes );
	LL( header->ofs_vertexarrays );
	LL( header->num_triangles );
	LL( header->ofs_triangles );
	LL( header->ofs_adjacency );
	LL( header->num_joints );
	LL( header->ofs_joints );
	LL( header->num_poses );
	LL( header->ofs_poses );
	LL( header->num_anims );
	LL( header->ofs_anims );
	LL( header->num_frames );
	LL( header->num_framechannels );
	LL( header->ofs_frames );
	LL( header->ofs_bounds );
	LL( header->num_comment );
	LL( header->ofs_comment );
	LL( header->num_extensions );
	LL( header->ofs_extensions );

	// check and swap vertex arrays
	if( IQM_CheckRange( header, header->ofs_vertexarrays,
			    header->num_vertexarrays,
			    sizeof(iqmVertexArray_t) ) ) {
		return qfalse;
	}
	vertexarray = (iqmVertexArray_t *)((byte *)header + header->ofs_vertexarrays);
	for( i = 0; i < header->num_vertexarrays; i++, vertexarray++ ) {
		int	j, n, *intPtr;

		if( vertexarray->size <= 0 || vertexarray->size > 4 ) {
			return qfalse;
		}

		// total number of values
		n = header->num_vertexes * vertexarray->size;

		switch( vertexarray->format ) {
		case IQM_BYTE:
		case IQM_UBYTE:
			// 1 byte, no swapping necessary
			if( IQM_CheckRange( header, vertexarray->offset,
					    n, sizeof(byte) ) ) {
				return qfalse;
			}
			break;
		case IQM_INT:
		case IQM_UINT:
		case IQM_FLOAT:
			// 4-byte swap
			if( IQM_CheckRange( header, vertexarray->offset,
					    n, sizeof(float) ) ) {
				return qfalse;
			}
			intPtr = (int *)((byte *)header + vertexarray->offset);
			for( j = 0; j < n; j++, intPtr++ ) {
				LL( *intPtr );
			}
			break;
		default:
			// not supported
			return qfalse;
			break;
		}

		switch( vertexarray->type ) {
		case IQM_POSITION:
		case IQM_NORMAL:
			if( vertexarray->format != IQM_FLOAT ||
			    vertexarray->size != 3 ) {
				return qfalse;
			}
			break;
		case IQM_TANGENT:
			if( vertexarray->format != IQM_FLOAT ||
			    vertexarray->size != 4 ) {
				return qfalse;
			}
			break;
		case IQM_TEXCOORD:
			if( vertexarray->format != IQM_FLOAT ||
			    vertexarray->size != 2 ) {
				return qfalse;
			}
			break;
		case IQM_BLENDINDEXES:
		case IQM_BLENDWEIGHTS:
			if( vertexarray->format != IQM_UBYTE ||
			    vertexarray->size != 4 ) {
				return qfalse;
			}
			break;
		case IQM_COLOR:
			if( vertexarray->format != IQM_UBYTE ||
			    vertexarray->size != 4 ) {
				return qfalse;
			}
			break;
		}
	}

	// check and swap triangles
	if( IQM_CheckRange( header, header->ofs_triangles,
			    header->num_triangles, sizeof(iqmTriangle_t) ) ) {
		return qfalse;
	}
	triangle = (iqmTriangle_t *)((byte *)header + header->ofs_triangles);
	for( i = 0; i < header->num_triangles; i++, triangle++ ) {
		LL( triangle->vertex[0] );
		LL( triangle->vertex[1] );
		LL( triangle->vertex[2] );
		
		if( triangle->vertex[0] < 0 || triangle->vertex[0] > header->num_vertexes ||
		    triangle->vertex[1] < 0 || triangle->vertex[1] > header->num_vertexes ||
		    triangle->vertex[2] < 0 || triangle->vertex[2] > header->num_vertexes ) {
			return qfalse;
		}
	}

	// check and swap meshes
	if( IQM_CheckRange( header, header->ofs_meshes,
			    header->num_meshes, sizeof(iqmMesh_t) ) ) {
		return qfalse;
	}
	mesh = (iqmMesh_t *)((byte *)header + header->ofs_meshes);
	for( i = 0; i < header->num_meshes; i++, mesh++) {
		LL( mesh->name );
		LL( mesh->material );
		LL( mesh->first_vertex );
		LL( mesh->num_vertexes );
		LL( mesh->first_triangle );
		LL( mesh->num_triangles );
		
		if( mesh->first_vertex >= header->num_vertexes ||
		    mesh->first_vertex + mesh->num_vertexes > header->num_vertexes ||
		    mesh->first_triangle >= header->num_triangles ||
		    mesh->first_triangle + mesh->num_triangles > header->num_triangles ||
		    mesh->name < 0 ||
		    mesh->name >= header->num_text ||
		    mesh->material < 0 ||
		    mesh->material >= header->num_text ) {
			return qfalse;
		}
	}

	// check and swap joints
	if( IQM_CheckRange( header, header->ofs_joints,
			    header->num_joints, sizeof(iqmJoint_t) ) ) {
		return qfalse;
	}
	joint = (iqmJoint_t *)((byte *)header + header->ofs_joints);
	joint_names = 0;
	for( i = 0; i < header->num_joints; i++, joint++ ) {
		LL( joint->name );
		LL( joint->parent );
		LL( joint->translate[0] );
		LL( joint->translate[1] );
		LL( joint->translate[2] );
		LL( joint->rotate[0] );
		LL( joint->rotate[1] );
		LL( joint->rotate[2] );
		LL( joint->scale[0] );
		LL( joint->scale[1] );
		LL( joint->scale[2] );

		if( joint->parent < -1 ||
		    joint->parent >= (int)header->num_joints ||
		    joint->name < 0 ||
		    joint->name >= (int)header->num_text ) {
			return qfalse;
		}
		joint_names += strlen( (char *)header + header->ofs_text +
				       joint->name ) + 1;
	}

	// check and swap poses
	if( header->num_poses != header->num_joints ) {
		return qfalse;
	}
	if( IQM_CheckRange( header, header->ofs_poses,
			    header->num_poses, sizeof(iqmPose_t) ) ) {
		return qfalse;
	}
	pose = (iqmPose_t *)((byte *)header + header->ofs_poses);
	for( i = 0; i < header->num_poses; i++, pose++ ) {
		LL( pose->parent );
		LL( pose->mask );
		LL( pose->channeloffset[0] );
		LL( pose->channeloffset[1] );
		LL( pose->channeloffset[2] );
		LL( pose->channeloffset[3] );
		LL( pose->channeloffset[4] );
		LL( pose->channeloffset[5] );
		LL( pose->channeloffset[6] );
		LL( pose->channeloffset[7] );
		LL( pose->channeloffset[8] );
		LL( pose->channelscale[0] );
		LL( pose->channelscale[1] );
		LL( pose->channelscale[2] );
		LL( pose->channelscale[3] );
		LL( pose->channelscale[4] );
		LL( pose->channelscale[5] );
		LL( pose->channelscale[6] );
		LL( pose->channelscale[7] );
		LL( pose->channelscale[8] );
	}

	// check and swap model bounds
	if(IQM_CheckRange(header, header->ofs_bounds,
			  header->num_frames, sizeof(*bounds)))
	{
		return qfalse;
	}
	bounds = (iqmBounds_t *) ((byte *) header + header->ofs_bounds);
	for(i = 0; i < header->num_poses; i++)
	{
		LL(bounds->bbmin[0]);
		LL(bounds->bbmin[1]);
		LL(bounds->bbmin[2]);
		LL(bounds->bbmax[0]);
		LL(bounds->bbmax[1]);
		LL(bounds->bbmax[2]);

		bounds++;
	}

	// allocate the model and copy the data
	size = sizeof(iqmData_t);
	size += header->num_meshes * sizeof( srfIQModel_t );
	size += header->num_joints * header->num_frames * 12 * sizeof( float );
	if(header->ofs_bounds)
		size += header->num_frames * 6 * sizeof(float);	// model bounds
	size += header->num_vertexes * 3 * sizeof(float);	// positions
	size += header->num_vertexes * 2 * sizeof(float);	// texcoords
	size += header->num_vertexes * 3 * sizeof(float);	// normals
	size += header->num_vertexes * 4 * sizeof(float);	// tangents
	size += header->num_vertexes * 4 * sizeof(byte);	// blendIndexes
	size += header->num_vertexes * 4 * sizeof(byte);	// blendWeights
	size += header->num_vertexes * 4 * sizeof(byte);	// colors
	size += header->num_joints * sizeof(int);		// parents
	size += header->num_triangles * 3 * sizeof(int);	// triangles
	size += joint_names;					// joint names

	mod->type = MOD_IQM;
	iqmData = (iqmData_t *)ri.Hunk_Alloc( size, h_low );
	mod->modelData = iqmData;

	// fill header
	iqmData->num_vertexes = header->num_vertexes;
	iqmData->num_triangles = header->num_triangles;
	iqmData->num_frames   = header->num_frames;
	iqmData->num_surfaces = header->num_meshes;
	iqmData->num_joints   = header->num_joints;
	iqmData->surfaces     = (srfIQModel_t *)(iqmData + 1);
	iqmData->poseMats     = (float *) (iqmData->surfaces + iqmData->num_surfaces);
	if(header->ofs_bounds)
	{
		iqmData->bounds       = iqmData->poseMats + 12 * header->num_joints * header->num_frames;
		iqmData->positions    = iqmData->bounds + 6 * header->num_frames;
	}
	else
		iqmData->positions    = iqmData->poseMats + 12 * header->num_joints * header->num_frames;
	iqmData->texcoords    = iqmData->positions + 3 * header->num_vertexes;
	iqmData->normals      = iqmData->texcoords + 2 * header->num_vertexes;
	iqmData->tangents     = iqmData->normals + 3 * header->num_vertexes;
	iqmData->blendIndexes = (byte *)(iqmData->tangents + 4 * header->num_vertexes);
	iqmData->blendWeights = iqmData->blendIndexes + 4 * header->num_vertexes;
	iqmData->colors       = iqmData->blendWeights + 4 * header->num_vertexes;
	iqmData->jointParents = (int *)(iqmData->colors + 4 * header->num_vertexes);
	iqmData->triangles    = iqmData->jointParents + header->num_joints;
	iqmData->names        = (char *)(iqmData->triangles + 3 * header->num_triangles);

	// calculate joint matrices and their inverses
	// they are needed only until the pose matrices are calculated
	jointMats = (float *)ri.Hunk_AllocateTempMemory( header->num_joints * 2 * 3 * 4 * sizeof(float) );
	mat = jointMats;
	joint = (iqmJoint_t *)((byte *)header + header->ofs_joints);
	for( i = 0; i < header->num_joints; i++, joint++ ) {
		float tmpMat[12];

		float rotW = DotProduct(joint->rotate, joint->rotate);
		rotW = -SQRTFAST(1.0f - rotW);

		float xx = 2.0f * joint->rotate[0] * joint->rotate[0];
		float yy = 2.0f * joint->rotate[1] * joint->rotate[1];
		float zz = 2.0f * joint->rotate[2] * joint->rotate[2];
		float xy = 2.0f * joint->rotate[0] * joint->rotate[1];
		float xz = 2.0f * joint->rotate[0] * joint->rotate[2];
		float yz = 2.0f * joint->rotate[1] * joint->rotate[2];
		float wx = 2.0f * rotW * joint->rotate[0];
		float wy = 2.0f * rotW * joint->rotate[1];
		float wz = 2.0f * rotW * joint->rotate[2];

		tmpMat[ 0] = joint->scale[0] * (1.0f - (yy + zz));
		tmpMat[ 1] = joint->scale[0] * (xy - wz);
		tmpMat[ 2] = joint->scale[0] * (xz + wy);
		tmpMat[ 3] = joint->translate[0];
		tmpMat[ 4] = joint->scale[1] * (xy + wz);
		tmpMat[ 5] = joint->scale[1] * (1.0f - (xx + zz));
		tmpMat[ 6] = joint->scale[1] * (yz - wx);
		tmpMat[ 7] = joint->translate[1];
		tmpMat[ 8] = joint->scale[2] * (xz - wy);
		tmpMat[ 9] = joint->scale[2] * (yz + wx);
		tmpMat[10] = joint->scale[2] * (1.0f - (xx + yy));
		tmpMat[11] = joint->translate[2];

		if( joint->parent >= 0 ) {
			// premultiply with parent-matrix
			Matrix34Multiply( jointMats + 2 * 12 * joint->parent,
					  tmpMat, mat);
		} else {
			Com_Memcpy( mat, tmpMat, sizeof(tmpMat) );
		}

		mat += 12;

		// compute the inverse matrix by combining the
		// inverse scale, rotation and translation
		tmpMat[ 0] = joint->scale[0] * (1.0f - (yy + zz));
		tmpMat[ 1] = joint->scale[1] * (xy + wz);
		tmpMat[ 2] = joint->scale[2] * (xz - wy);
		tmpMat[ 3] = -DotProduct((tmpMat + 0), joint->translate);
		tmpMat[ 4] = joint->scale[0] * (xy - wz);
		tmpMat[ 5] = joint->scale[1] * (1.0f - (xx + zz));
		tmpMat[ 6] = joint->scale[2] * (yz + wx);
		tmpMat[ 7] = -DotProduct((tmpMat + 4), joint->translate);
		tmpMat[ 8] = joint->scale[0] * (xz + wy);
		tmpMat[ 9] = joint->scale[1] * (yz - wx);
		tmpMat[10] = joint->scale[2] * (1.0f - (xx + yy));
		tmpMat[11] = -DotProduct((tmpMat + 8), joint->translate);

		if( joint->parent >= 0 ) {
			// premultiply with inverse parent-matrix
			Matrix34Multiply( tmpMat,
					  jointMats + 2 * 12 * joint->parent + 12,
					  mat);
		} else {
			Com_Memcpy( mat, tmpMat, sizeof(tmpMat) );
		}

		mat += 12;
	}

	// calculate pose matrices
	framedata = (unsigned short *)((byte *)header + header->ofs_frames);
	mat = iqmData->poseMats;
	for( i = 0; i < header->num_frames; i++ ) {
		pose = (iqmPose_t *)((byte *)header + header->ofs_poses);
		for( j = 0; j < header->num_poses; j++, pose++ ) {
			vec3_t	translate, rotate, scale;
			float	mat1[12], mat2[12];

			translate[0] = pose->channeloffset[0];
			if( pose->mask & 0x001)
				translate[0] += *framedata++ * pose->channelscale[0];
			translate[1] = pose->channeloffset[1];
			if( pose->mask & 0x002)
				translate[1] += *framedata++ * pose->channelscale[1];
			translate[2] = pose->channeloffset[2];
			if( pose->mask & 0x004)
				translate[2] += *framedata++ * pose->channelscale[2];
			rotate[0] = pose->channeloffset[3];
			if( pose->mask & 0x008)
				rotate[0] += *framedata++ * pose->channelscale[3];
			rotate[1] = pose->channeloffset[4];
			if( pose->mask & 0x010)
				rotate[1] += *framedata++ * pose->channelscale[4];
			rotate[2] = pose->channeloffset[5];
			if( pose->mask & 0x020)
				rotate[2] += *framedata++ * pose->channelscale[5];
			scale[0] = pose->channeloffset[6];
			if( pose->mask & 0x040)
				scale[0] += *framedata++ * pose->channelscale[6];
			scale[1] = pose->channeloffset[7];
			if( pose->mask & 0x080)
				scale[1] += *framedata++ * pose->channelscale[7];
			scale[2] = pose->channeloffset[8];
			if( pose->mask & 0x100)
				scale[2] += *framedata++ * pose->channelscale[8];

			// construct transformation matrix
			float rotW = DotProduct(rotate, rotate);
			rotW = -SQRTFAST(1.0f - rotW);

			float xx = 2.0f * rotate[0] * rotate[0];
			float yy = 2.0f * rotate[1] * rotate[1];
			float zz = 2.0f * rotate[2] * rotate[2];
			float xy = 2.0f * rotate[0] * rotate[1];
			float xz = 2.0f * rotate[0] * rotate[2];
			float yz = 2.0f * rotate[1] * rotate[2];
			float wx = 2.0f * rotW * rotate[0];
			float wy = 2.0f * rotW * rotate[1];
			float wz = 2.0f * rotW * rotate[2];

			mat1[ 0] = scale[0] * (1.0f - (yy + zz));
			mat1[ 1] = scale[0] * (xy - wz);
			mat1[ 2] = scale[0] * (xz + wy);
			mat1[ 3] = translate[0];
			mat1[ 4] = scale[1] * (xy + wz);
			mat1[ 5] = scale[1] * (1.0f - (xx + zz));
			mat1[ 6] = scale[1] * (yz - wx);
			mat1[ 7] = translate[1];
			mat1[ 8] = scale[2] * (xz - wy);
			mat1[ 9] = scale[2] * (yz + wx);
			mat1[10] = scale[2] * (1.0f - (xx + yy));
			mat1[11] = translate[2];
			
			if( pose->parent >= 0 ) {
				Matrix34Multiply( jointMats + 12 * 2 * pose->parent,
						  mat1, mat2 );
			} else {
				Com_Memcpy( mat2, mat1, sizeof(mat1) );
			}
			
			Matrix34Multiply( mat2, jointMats + 12 * (2 * j + 1), mat );
			mat += 12;
		}
	}
	ri.Hunk_FreeTempMemory( jointMats );

	// register shaders
	// overwrite the material offset with the shader index
	mesh = (iqmMesh_t *)((byte *)header + header->ofs_meshes);
	surface = iqmData->surfaces;
	str = (char *)header + header->ofs_text;
	for( i = 0; i < header->num_meshes; i++, mesh++, surface++ ) {
		surface->surfaceType = SF_IQM;
		surface->shader = R_FindShader( str + mesh->material, LIGHTMAP_NONE, qtrue );
		if( surface->shader->defaultShader )
			surface->shader = tr.defaultShader;
		surface->data = iqmData;
		surface->first_vertex = mesh->first_vertex;
		surface->num_vertexes = mesh->num_vertexes;
		surface->first_triangle = mesh->first_triangle;
		surface->num_triangles = mesh->num_triangles;
        }

	// copy vertexarrays and indexes
	vertexarray = (iqmVertexArray_t *)((byte *)header + header->ofs_vertexarrays);
	for( i = 0; i < header->num_vertexarrays; i++, vertexarray++ ) {
		int	n;

		// total number of values
		n = header->num_vertexes * vertexarray->size;

		switch( vertexarray->type ) {
		case IQM_POSITION:
			Com_Memcpy( iqmData->positions,
				    (byte *)header + vertexarray->offset,
				    n * sizeof(float) );
			break;
		case IQM_NORMAL:
			Com_Memcpy( iqmData->normals,
				    (byte *)header + vertexarray->offset,
				    n * sizeof(float) );
			break;
		case IQM_TANGENT:
			Com_Memcpy( iqmData->tangents,
				    (byte *)header + vertexarray->offset,
				    n * sizeof(float) );
			break;
		case IQM_TEXCOORD:
			Com_Memcpy( iqmData->texcoords,
				    (byte *)header + vertexarray->offset,
				    n * sizeof(float) );
			break;
		case IQM_BLENDINDEXES:
			Com_Memcpy( iqmData->blendIndexes,
				    (byte *)header + vertexarray->offset,
				    n * sizeof(byte) );
			break;
		case IQM_BLENDWEIGHTS:
			Com_Memcpy( iqmData->blendWeights,
				    (byte *)header + vertexarray->offset,
				    n * sizeof(byte) );
			break;
		case IQM_COLOR:
			Com_Memcpy( iqmData->colors,
				    (byte *)header + vertexarray->offset,
				    n * sizeof(byte) );
			break;
		}
	}

	// copy joint parents
	joint = (iqmJoint_t *)((byte *)header + header->ofs_joints);
	for( i = 0; i < header->num_joints; i++, joint++ ) {
		iqmData->jointParents[i] = joint->parent;
	}

	// copy triangles
	triangle = (iqmTriangle_t *)((byte *)header + header->ofs_triangles);
	for( i = 0; i < header->num_triangles; i++, triangle++ ) {
		iqmData->triangles[3*i+0] = triangle->vertex[0];
		iqmData->triangles[3*i+1] = triangle->vertex[1];
		iqmData->triangles[3*i+2] = triangle->vertex[2];
	}

	// copy joint names
	str = iqmData->names;
	joint = (iqmJoint_t *)((byte *)header + header->ofs_joints);
	for( i = 0; i < header->num_joints; i++, joint++ ) {
		char *name = (char *)header + header->ofs_text +
			joint->name;
		int len = strlen( name ) + 1;
		Com_Memcpy( str, name, len );
		str += len;
	}

	// copy model bounds
	if(header->ofs_bounds)
	{
		mat = iqmData->bounds;
		bounds = (iqmBounds_t *) ((byte *) header + header->ofs_bounds);
		for(i = 0; i < header->num_frames; i++)
		{
			mat[0] = bounds->bbmin[0];
			mat[1] = bounds->bbmin[1];
			mat[2] = bounds->bbmin[2];
			mat[3] = bounds->bbmax[0];
			mat[4] = bounds->bbmax[1];
			mat[5] = bounds->bbmax[2];

			mat += 6;
			bounds++;
		}
	}

	return qtrue;
}

/*
=================
R_AddIQMSurfaces

Add all surfaces of this model
=================
*/
void R_AddIQMSurfaces( trRefEntity_t *ent ) {
	iqmData_t		*data;
	srfIQModel_t		*surface;
	int			i;

	data = tr.currentModel->modelData;
	surface = data->surfaces;

	R_SetupEntityLighting( &tr.refdef, ent );

	for ( i = 0 ; i < data->num_surfaces ; i++ ) {
		R_AddDrawSurf( &surface->surfaceType,
			       surface->shader, 0 /*fogNum*/, 0 );
		surface++;
	}
}


static void ComputeJointMats( iqmData_t *data, int frame, int oldframe,
			      float backlerp, float *mat ) {
	float	*mat1, *mat2;
	int	*joint = data->jointParents;
	int	i;

	if (  oldframe == frame ) {
		mat1 = mat2 = data->poseMats + 12 * data->num_joints * frame;
		for( i = 0; i < data->num_joints; i++, joint++ ) {
			if( *joint >= 0 ) {
				Matrix34Multiply( mat + 12 * *joint,
						  mat1 + 12*i, mat + 12*i );
			} else {
				Com_Memcpy( mat + 12*i, mat1 + 12*i, 12 * sizeof(float) );
			}
		}
	} else  {
		mat1 = data->poseMats + 12 * data->num_joints * frame;
		mat2 = data->poseMats + 12 * data->num_joints * oldframe;
		
		for( i = 0; i < 12 * data->num_joints; i++, joint++ ) {
			if( *joint >= 0 ) {
				float tmpMat[12];
				InterpolateMatrix( mat1 + 12*i, mat2 + 12*i,
						   backlerp, tmpMat );
				Matrix34Multiply( mat + 12 * *joint,
						  tmpMat, mat + 12*i );
				
			} else {
				InterpolateMatrix( mat1 + 12*i, mat2 + 12*i,
						   backlerp, mat );
			}
		}
	}
}


/*
=================
RB_AddIQMSurfaces

Compute vertices for this model surface
=================
*/
void RB_IQMSurfaceAnim( surfaceType_t *surface ) {
	srfIQModel_t	*surf = (srfIQModel_t *)surface;
	iqmData_t	*data = surf->data;
	int		i;

	vec4_t		*outXYZ = &tess.xyz[tess.numVertexes];
	vec4_t		*outNormal = &tess.normal[tess.numVertexes];
	vec2_t		(*outTexCoord)[2] = &tess.texCoords[tess.numVertexes];
	color4ub_t	*outColor = &tess.vertexColors[tess.numVertexes];

	float	mat[data->num_joints * 12];
	int	frame = backEnd.currentEntity->e.frame % data->num_frames;
	int	oldframe = backEnd.currentEntity->e.oldframe % data->num_frames;
	float	backlerp = backEnd.currentEntity->e.backlerp;

	RB_CHECKOVERFLOW( surf->num_vertexes, surf->num_triangles * 3 );

	// compute interpolated joint matrices
	ComputeJointMats( data, frame, oldframe, backlerp, mat );

	// transform vertexes and fill other data
	for( i = 0; i < surf->num_vertexes;
	     i++, outXYZ++, outNormal++, outTexCoord++, outColor++ ) {
		int	j, k;
		float	vtxMat[12];
		float	nrmMat[9];
		int	vtx = i + surf->first_vertex;

		// compute the vertex matrix by blending the up to
		// four blend weights
		for( k = 0; k < 12; k++ )
			vtxMat[k] = data->blendWeights[4*vtx]
				* mat[12*data->blendIndexes[4*vtx] + k];
		for( j = 1; j < 4; j++ ) {
			if( data->blendWeights[4*vtx + j] <= 0 )
				break;
			for( k = 0; k < 12; k++ )
				vtxMat[k] += data->blendWeights[4*vtx + j]
					* mat[12*data->blendIndexes[4*vtx + j] + k];
		}
		for( k = 0; k < 12; k++ )
			vtxMat[k] *= 1.0f / 255.0f;

		// compute the normal matrix as transpose of the adjoint
		// of the vertex matrix
		nrmMat[ 0] = vtxMat[ 5]*vtxMat[10] - vtxMat[ 6]*vtxMat[ 9];
		nrmMat[ 1] = vtxMat[ 6]*vtxMat[ 8] - vtxMat[ 4]*vtxMat[10];
		nrmMat[ 2] = vtxMat[ 4]*vtxMat[ 9] - vtxMat[ 5]*vtxMat[ 8];
		nrmMat[ 3] = vtxMat[ 2]*vtxMat[ 9] - vtxMat[ 1]*vtxMat[10];
		nrmMat[ 4] = vtxMat[ 0]*vtxMat[10] - vtxMat[ 2]*vtxMat[ 8];
		nrmMat[ 5] = vtxMat[ 1]*vtxMat[ 8] - vtxMat[ 0]*vtxMat[ 9];
		nrmMat[ 6] = vtxMat[ 1]*vtxMat[ 6] - vtxMat[ 2]*vtxMat[ 5];
		nrmMat[ 7] = vtxMat[ 2]*vtxMat[ 4] - vtxMat[ 0]*vtxMat[ 6];
		nrmMat[ 8] = vtxMat[ 0]*vtxMat[ 5] - vtxMat[ 1]*vtxMat[ 4];

		(*outTexCoord)[0][0] = data->texcoords[2*vtx + 0];
		(*outTexCoord)[0][1] = data->texcoords[2*vtx + 1];
		(*outTexCoord)[1][0] = (*outTexCoord)[0][0];
		(*outTexCoord)[1][1] = (*outTexCoord)[0][1];

		(*outXYZ)[0] =
			vtxMat[ 0] * data->positions[3*vtx+0] +
			vtxMat[ 1] * data->positions[3*vtx+1] +
			vtxMat[ 2] * data->positions[3*vtx+2] +
			vtxMat[ 3];
		(*outXYZ)[1] =
			vtxMat[ 4] * data->positions[3*vtx+0] +
			vtxMat[ 5] * data->positions[3*vtx+1] +
			vtxMat[ 6] * data->positions[3*vtx+2] +
			vtxMat[ 7];
		(*outXYZ)[2] =
			vtxMat[ 8] * data->positions[3*vtx+0] +
			vtxMat[ 9] * data->positions[3*vtx+1] +
			vtxMat[10] * data->positions[3*vtx+2] +
			vtxMat[11];
		(*outXYZ)[3] = 1.0f;

		(*outNormal)[0] =
			nrmMat[ 0] * data->normals[3*vtx+0] +
			nrmMat[ 1] * data->normals[3*vtx+1] +
			nrmMat[ 2] * data->normals[3*vtx+2];
		(*outNormal)[1] =
			nrmMat[ 3] * data->normals[3*vtx+0] +
			nrmMat[ 4] * data->normals[3*vtx+1] +
			nrmMat[ 5] * data->normals[3*vtx+2];
		(*outNormal)[2] =
			nrmMat[ 6] * data->normals[3*vtx+0] +
			nrmMat[ 7] * data->normals[3*vtx+1] +
			nrmMat[ 8] * data->normals[3*vtx+2];
		(*outNormal)[3] = 0.0f;

		(*outColor)[0] = data->colors[4*vtx+0];
		(*outColor)[1] = data->colors[4*vtx+1];
		(*outColor)[2] = data->colors[4*vtx+2];
		(*outColor)[3] = data->colors[4*vtx+3];
	}

	int	*tri = data->triangles;
	tri += 3 * surf->first_triangle;

	glIndex_t	*ptr = &tess.indexes[tess.numIndexes];
	glIndex_t	base = tess.numVertexes;

	for( i = 0; i < surf->num_triangles; i++ ) {
		*ptr++ = base + (*tri++ - surf->first_vertex);
		*ptr++ = base + (*tri++ - surf->first_vertex);
		*ptr++ = base + (*tri++ - surf->first_vertex);
	}

	tess.numIndexes += 3 * surf->num_triangles;
	tess.numVertexes += surf->num_vertexes;
}

int R_IQMLerpTag( orientation_t *tag, iqmData_t *data,
		  int startFrame, int endFrame, 
		  float frac, const char *tagName ) {
	int	joint;
	char	*names = data->names;
	float	mat[data->num_joints * 12];

	// get joint number by reading the joint names
	for( joint = 0; joint < data->num_joints; joint++ ) {
		if( !strcmp( tagName, names ) )
			break;
		names += strlen( names ) + 1;
	}
	if( joint >= data->num_joints )
		return qfalse;

	ComputeJointMats( data, startFrame, endFrame, frac, mat );
	tag->axis[0][0] = mat[12 * joint + 0];
	tag->axis[1][0] = mat[12 * joint + 1];
	tag->axis[2][0] = mat[12 * joint + 2];
	tag->origin[0] = mat[12 * joint + 3];
	tag->axis[0][1] = mat[12 * joint + 4];
	tag->axis[1][1] = mat[12 * joint + 5];
	tag->axis[2][1] = mat[12 * joint + 6];
	tag->origin[1] = mat[12 * joint + 7];
	tag->axis[0][2] = mat[12 * joint + 8];
	tag->axis[1][2] = mat[12 * joint + 9];
	tag->axis[2][2] = mat[12 * joint + 10];
	tag->origin[0] = mat[12 * joint + 11];

	return qfalse;
}