コード例 #1
0
ファイル: bn_mat.c プロジェクト: kanzure/brlcad
static int
test_bn_mat_ae(int argc, char *argv[])
{
    double az, el;
    mat_t expected, actual;

    if (argc != 5) {
	bu_exit(1, "<args> format: az el <expected_result> [%s]\n", argv[0]);
    }

    sscanf(argv[2], "%lg", &az);
    sscanf(argv[3], "%lg", &el);
    scan_mat_args(argv, 4, &expected);

    bn_mat_ae(actual, az, el);
    return !mat_equal(expected, actual);
}
コード例 #2
0
ファイル: bn_tcl.c プロジェクト: cciechad/brlcad
int
bn_math_cmd(ClientData clientData, Tcl_Interp *interp, int argc, char **argv)
{
    void (*math_func)();
    struct bu_vls result;

    math_func = (void (*)())clientData; /* object-to-function cast */
    bu_vls_init(&result);

    if (math_func == bn_mat_mul) {
	mat_t o, a, b;
	if (argc < 3 || bn_decode_mat(a, argv[1]) < 16 ||
	    bn_decode_mat(b, argv[2]) < 16) {
	    bu_vls_printf(&result, "usage: %s matA matB", argv[0]);
	    goto error;
	}
	bn_mat_mul(o, a, b);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_mat_inv || math_func == bn_mat_trn) {
	mat_t o, a;

	if (argc < 2 || bn_decode_mat(a, argv[1]) < 16) {
	    bu_vls_printf(&result, "usage: %s mat", argv[0]);
	    goto error;
	}
	(*math_func)(o, a);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_matXvec) {
	mat_t m;
	hvect_t i, o;
	if (argc < 3 || bn_decode_mat(m, argv[1]) < 16 ||
	    bn_decode_hvect(i, argv[2]) < 4) {
	    bu_vls_printf(&result, "usage: %s mat hvect", argv[0]);
	    goto error;
	}
	bn_matXvec(o, m, i);
	bn_encode_hvect(&result, o);
    } else if (math_func == bn_mat4x3pnt) {
	mat_t m;
	point_t i, o;
	if (argc < 3 || bn_decode_mat(m, argv[1]) < 16 ||
	    bn_decode_vect(i, argv[2]) < 3) {
	    bu_vls_printf(&result, "usage: %s mat point", argv[0]);
	    goto error;
	}
	bn_mat4x3pnt(o, m, i);
	bn_encode_vect(&result, o);
    } else if (math_func == bn_mat4x3vec) {
	mat_t m;
	vect_t i, o;
	if (argc < 3 || bn_decode_mat(m, argv[1]) < 16 ||
	    bn_decode_vect(i, argv[2]) < 3) {
	    bu_vls_printf(&result, "usage: %s mat vect", argv[0]);
	    goto error;
	}
	bn_mat4x3vec(o, m, i);
	bn_encode_vect(&result, o);
    } else if (math_func == bn_hdivide) {
	hvect_t i;
	vect_t o;
	if (argc < 2 || bn_decode_hvect(i, argv[1]) < 4) {
	    bu_vls_printf(&result, "usage: %s hvect", argv[0]);
	    goto error;
	}
	bn_hdivide(o, i);
	bn_encode_vect(&result, o);
    } else if (math_func == bn_vjoin1) {
	point_t o;
	point_t b, d;
	fastf_t c;

	if (argc < 4) {
	    bu_vls_printf(&result, "usage: %s pnt scale dir", argv[0]);
	    goto error;
	}
	if ( bn_decode_vect(b, argv[1]) < 3) goto error;
	if (Tcl_GetDouble(interp, argv[2], &c) != TCL_OK) goto error;
	if ( bn_decode_vect(d, argv[3]) < 3) goto error;

	VJOIN1( o, b, c, d );	/* bn_vjoin1( o, b, c, d ) */
	bn_encode_vect(&result, o);

    } else if ( math_func == bn_vblend) {
	point_t a, c, e;
	fastf_t b, d;

	if ( argc < 5 ) {
	    bu_vls_printf(&result, "usage: %s scale pnt scale pnt", argv[0]);
	    goto error;
	}

	if ( Tcl_GetDouble(interp, argv[1], &b) != TCL_OK) goto error;
	if ( bn_decode_vect( c, argv[2] ) < 3) goto error;
	if ( Tcl_GetDouble(interp, argv[3], &d) != TCL_OK) goto error;
	if ( bn_decode_vect( e, argv[4] ) < 3) goto error;

	VBLEND2( a, b, c, d, e )
	    bn_encode_vect( &result, a );

    } else if (math_func == bn_mat_ae) {
	mat_t o;
	double az, el;

	if (argc < 3) {
	    bu_vls_printf(&result, "usage: %s azimuth elevation", argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[1], &az) != TCL_OK) goto error;
	if (Tcl_GetDouble(interp, argv[2], &el) != TCL_OK) goto error;

	bn_mat_ae(o, (fastf_t)az, (fastf_t)el);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_ae_vec) {
	fastf_t az, el;
	vect_t v;

	if (argc < 2 || bn_decode_vect(v, argv[1]) < 3) {
	    bu_vls_printf(&result, "usage: %s vect", argv[0]);
	    goto error;
	}

	bn_ae_vec(&az, &el, v);
	bu_vls_printf(&result, "%g %g", az, el);
    } else if (math_func == bn_aet_vec) {
	fastf_t az, el, twist, accuracy;
	vect_t vec_ae, vec_twist;

	if (argc < 4 || bn_decode_vect(vec_ae, argv[1]) < 3 ||
	    bn_decode_vect(vec_twist, argv[2]) < 3 ||
	    sscanf(argv[3], "%lf", &accuracy) < 1) {
	    bu_vls_printf(&result, "usage: %s vec_ae vec_twist accuracy",
			  argv[0]);
	    goto error;
	}

	bn_aet_vec(&az, &el, &twist, vec_ae, vec_twist, accuracy);
	bu_vls_printf(&result, "%g %g %g", az, el, twist);
    } else if (math_func == bn_mat_angles) {
	mat_t o;
	double alpha, beta, ggamma;

	if (argc < 4) {
	    bu_vls_printf(&result, "usage: %s alpha beta gamma", argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[1], &alpha) != TCL_OK)  goto error;
	if (Tcl_GetDouble(interp, argv[2], &beta) != TCL_OK)   goto error;
	if (Tcl_GetDouble(interp, argv[3], &ggamma) != TCL_OK) goto error;

	bn_mat_angles(o, alpha, beta, ggamma);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_eigen2x2) {
	fastf_t val1, val2;
	vect_t vec1, vec2;
	double a, b, c;

	if (argc < 4) {
	    bu_vls_printf(&result, "usage: %s a b c", argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[1], &a) != TCL_OK) goto error;
	if (Tcl_GetDouble(interp, argv[2], &c) != TCL_OK) goto error;
	if (Tcl_GetDouble(interp, argv[3], &b) != TCL_OK) goto error;

	bn_eigen2x2(&val1, &val2, vec1, vec2, (fastf_t)a, (fastf_t)b,
		    (fastf_t)c);
	bu_vls_printf(&result, "%g %g {%g %g %g} {%g %g %g}", val1, val2,
		      V3ARGS(vec1), V3ARGS(vec2));
    } else if (math_func == bn_mat_fromto) {
	mat_t o;
	vect_t from, to;

	if (argc < 3 || bn_decode_vect(from, argv[1]) < 3 ||
	    bn_decode_vect(to, argv[2]) < 3) {
	    bu_vls_printf(&result, "usage: %s vecFrom vecTo", argv[0]);
	    goto error;
	}
	bn_mat_fromto(o, from, to);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_mat_xrot || math_func == bn_mat_yrot ||
	       math_func == bn_mat_zrot) {
	mat_t o;
	double s, c;
	if (argc < 3) {
	    bu_vls_printf(&result, "usage: %s sinAngle cosAngle", argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[1], &s) != TCL_OK) goto error;
	if (Tcl_GetDouble(interp, argv[2], &c) != TCL_OK) goto error;

	(*math_func)(o, s, c);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_mat_lookat) {
	mat_t o;
	vect_t dir;
	int yflip;
	if (argc < 3 || bn_decode_vect(dir, argv[1]) < 3) {
	    bu_vls_printf(&result, "usage: %s dir yflip", argv[0]);
	    goto error;
	}
	if (Tcl_GetBoolean(interp, argv[2], &yflip) != TCL_OK) goto error;

	bn_mat_lookat(o, dir, yflip);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_vec_ortho || math_func == bn_vec_perp) {
	vect_t ov, vec;

	if (argc < 2 || bn_decode_vect(vec, argv[1]) < 3) {
	    bu_vls_printf(&result, "usage: %s vec", argv[0]);
	    goto error;
	}

	(*math_func)(ov, vec);
	bn_encode_vect(&result, ov);
    } else if (math_func == bn_mat_scale_about_pt_wrapper) {
	mat_t o;
	vect_t v;
	double scale;
	int status;

	if (argc < 3 || bn_decode_vect(v, argv[1]) < 3) {
	    bu_vls_printf(&result, "usage: %s pt scale", argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[2], &scale) != TCL_OK) goto error;

	bn_mat_scale_about_pt_wrapper(&status, o, v, scale);
	if (status != 0) {
	    bu_vls_printf(&result, "error performing calculation");
	    goto error;
	}
	bn_encode_mat(&result, o);
    } else if (math_func == bn_mat_xform_about_pt) {
	mat_t o, xform;
	vect_t v;

	if (argc < 3 || bn_decode_mat(xform, argv[1]) < 16 ||
	    bn_decode_vect(v, argv[2]) < 3) {
	    bu_vls_printf(&result, "usage: %s xform pt", argv[0]);
	    goto error;
	}

	bn_mat_xform_about_pt(o, xform, v);
	bn_encode_mat(&result, o);
    } else if (math_func == bn_mat_arb_rot) {
	mat_t o;
	point_t pt;
	vect_t dir;
	double angle;

	if (argc < 4 || bn_decode_vect(pt, argv[1]) < 3 ||
	    bn_decode_vect(dir, argv[2]) < 3) {
	    bu_vls_printf(&result, "usage: %s pt dir angle", argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[3], &angle) != TCL_OK)
	    return TCL_ERROR;

	bn_mat_arb_rot(o, pt, dir, (fastf_t)angle);
	bn_encode_mat(&result, o);
    } else if (math_func == quat_mat2quat) {
	mat_t mat;
	quat_t quat;

	if (argc < 2 || bn_decode_mat(mat, argv[1]) < 16) {
	    bu_vls_printf(&result, "usage: %s mat", argv[0]);
	    goto error;
	}

	quat_mat2quat(quat, mat);
	bn_encode_quat(&result, quat);
    } else if (math_func == quat_quat2mat) {
	mat_t mat;
	quat_t quat;

	if (argc < 2 || bn_decode_quat(quat, argv[1]) < 4) {
	    bu_vls_printf(&result, "usage: %s quat", argv[0]);
	    goto error;
	}

	quat_quat2mat(mat, quat);
	bn_encode_mat(&result, mat);
    } else if (math_func == bn_quat_distance_wrapper) {
	quat_t q1, q2;
	double d;

	if (argc < 3 || bn_decode_quat(q1, argv[1]) < 4 ||
	    bn_decode_quat(q2, argv[2]) < 4) {
	    bu_vls_printf(&result, "usage: %s quatA quatB", argv[0]);
	    goto error;
	}

	bn_quat_distance_wrapper(&d, q1, q2);
	bu_vls_printf(&result, "%g", d);
    } else if (math_func == quat_double || math_func == quat_bisect ||
	       math_func == quat_make_nearest) {
	quat_t oqot, q1, q2;

	if (argc < 3 || bn_decode_quat(q1, argv[1]) < 4 ||
	    bn_decode_quat(q2, argv[2]) < 4) {
	    bu_vls_printf(&result, "usage: %s quatA quatB", argv[0]);
	    goto error;
	}

	(*math_func)(oqot, q1, q2);
	bn_encode_quat(&result, oqot);
    } else if (math_func == quat_slerp) {
	quat_t oq, q1, q2;
	double d;

	if (argc < 4 || bn_decode_quat(q1, argv[1]) < 4 ||
	    bn_decode_quat(q2, argv[2]) < 4) {
	    bu_vls_printf(&result, "usage: %s quat1 quat2 factor", argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[3], &d) != TCL_OK) goto error;

	quat_slerp(oq, q1, q2, d);
	bn_encode_quat(&result, oq);
    } else if (math_func == quat_sberp) {
	quat_t oq, q1, qa, qb, q2;
	double d;

	if (argc < 6 || bn_decode_quat(q1, argv[1]) < 4 ||
	    bn_decode_quat(qa, argv[2]) < 4 || bn_decode_quat(qb, argv[3]) < 4 ||
	    bn_decode_quat(q2, argv[4]) < 4) {
	    bu_vls_printf(&result, "usage: %s quat1 quatA quatB quat2 factor",
			  argv[0]);
	    goto error;
	}
	if (Tcl_GetDouble(interp, argv[5], &d) != TCL_OK) goto error;

	quat_sberp(oq, q1, qa, qb, q2, d);
	bn_encode_quat(&result, oq);
    } else if (math_func == quat_exp || math_func == quat_log) {
	quat_t qout, qin;

	if (argc < 2 || bn_decode_quat(qin, argv[1]) < 4) {
	    bu_vls_printf(&result, "usage: %s quat", argv[0]);
	    goto error;
	}

	(*math_func)(qout, qin);
	bn_encode_quat(&result, qout);
    } else if (math_func == (void (*)())bn_isect_line3_line3) {
	double t, u;
	point_t pt, a;
	vect_t dir, c;
	int i;
	static const struct bn_tol tol = {
	    BN_TOL_MAGIC, 0.005, 0.005*0.005, 1e-6, 1-1e-6
	};
	if (argc != 5) {
	    bu_vls_printf(&result,
			  "Usage: bn_isect_line3_line3 pt dir pt dir (%d args specified)",
			  argc-1);
	    goto error;
	}

	if (bn_decode_vect(pt, argv[1]) < 3) {
	    bu_vls_printf(&result, "bn_isect_line3_line3 no pt: %s\n", argv[0]);
	    goto error;
	}
	if (bn_decode_vect(dir, argv[2]) < 3) {
	    bu_vls_printf(&result, "bn_isect_line3_line3 no dir: %s\n", argv[0]);
	    goto error;
	}
	if (bn_decode_vect(a, argv[3]) < 3) {
	    bu_vls_printf(&result, "bn_isect_line3_line3 no a pt: %s\n", argv[0]);
	    goto error;
	}
	if (bn_decode_vect(c, argv[4]) < 3) {
	    bu_vls_printf(&result, "bn_isect_line3_line3 no c dir: %s\n", argv[0]);
	    goto error;
	}
	i = bn_isect_line3_line3(&t, &u, pt, dir, a, c, &tol);
	if (i != 1) {
	    bu_vls_printf(&result, "bn_isect_line3_line3 no intersection: %s\n", argv[0]);
	    goto error;
	}

	VJOIN1(a, pt, t, dir);
	bn_encode_vect(&result, a);

    } else if (math_func == (void (*)())bn_isect_line2_line2) {
	double dist[2];
	point_t pt, a;
	vect_t dir, c;
	int i;
	static const struct bn_tol tol = {
	    BN_TOL_MAGIC, 0.005, 0.005*0.005, 1e-6, 1-1e-6
	};

	if (argc != 5) {
	    bu_vls_printf(&result,
			  "Usage: bn_isect_line2_line2 pt dir pt dir (%d args specified)",
			  argc-1);
	    goto error;
	}

	/* i = bn_isect_line2_line2 {0 0} {1 0} {1 1} {0 -1} */

	VSETALL(pt, 0.0);
	VSETALL(dir, 0.0);
	VSETALL(a, 0.0);
	VSETALL(c, 0.0);

	if (bn_decode_vect(pt, argv[1]) < 2) {
	    bu_vls_printf(&result, "bn_isect_line2_line2 no pt: %s\n", argv[0]);
	    goto error;
	}
	if (bn_decode_vect(dir, argv[2]) < 2) {
	    bu_vls_printf(&result, "bn_isect_line2_line2 no dir: %s\n", argv[0]);
	    goto error;
	}
	if (bn_decode_vect(a, argv[3]) < 2) {
	    bu_vls_printf(&result, "bn_isect_line2_line2 no a pt: %s\n", argv[0]);
	    goto error;
	}
	if (bn_decode_vect(c, argv[4]) < 2) {
	    bu_vls_printf(&result, "bn_isect_line2_line2 no c dir: %s\n", argv[0]);
	    goto error;
	}
	i = bn_isect_line2_line2(dist, pt, dir, a, c, &tol);
	if (i != 1) {
	    bu_vls_printf(&result, "bn_isect_line2_line2 no intersection: %s\n", argv[0]);
	    goto error;
	}

	VJOIN1(a, pt, dist[0], dir);
	bu_vls_printf(&result, "%g %g", a[0], a[1]);

    } else {
	bu_vls_printf(&result, "libbn/bn_tcl.c: math function %s not supported yet\n", argv[0]);
	goto error;
    }

    Tcl_AppendResult(interp, bu_vls_addr(&result), (char *)NULL);
    bu_vls_free(&result);
    return TCL_OK;

 error:
    Tcl_AppendResult(interp, bu_vls_addr(&result), (char *)NULL);
    bu_vls_free(&result);
    return TCL_ERROR;
}
コード例 #3
0
/*
 *  Returns -
 *	-2	unknown keyword
 *	-1	error in processing keyword
 *	 0	OK
 */
int
multi_words( char *words[], int	nwords )
{

    if ( strcmp( words[0], "rot" ) == 0 )  {
	mat_t	mat;

	/* Expects rotations rx, ry, rz, in degrees */
	if ( nwords < 4 )  return(-1);
	MAT_IDN( mat );
	bn_mat_angles( mat,
		       atof( words[1] ),
		       atof( words[2] ),
		       atof( words[3] ) );
	out_mat( mat, stdout );
	return(0);
    }
    if ( strcmp( words[0], "xlate" ) == 0 )  {
	mat_t	mat;

	if ( nwords < 4 )  return(-1);
	/* Expects translations tx, ty, tz */
	MAT_IDN( mat );
	MAT_DELTAS( mat,
		    atof( words[1] ),
		    atof( words[2] ),
		    atof( words[3] ) );
	out_mat( mat, stdout );
	return(0);
    }
    if ( strcmp( words[0], "rot_at" ) == 0 )  {
	mat_t	mat;
	mat_t	mat1;
	mat_t	mat2;
	mat_t	mat3;

	/* JG - Expects x, y, z, rx, ry, rz               */
	/* Translation back to the origin by (-x, -y, -z)   */
	/* is done first, then the rotation, and finally  */
	/* back into the original position by (+x, +y, +z). */

	if ( nwords < 7 )  return(-1);

	MAT_IDN( mat1 );
	MAT_IDN( mat2 );
	MAT_IDN( mat3 );

	MAT_DELTAS( mat1,
		    -atof( words[1] ),
		    -atof( words[2] ),
		    -atof( words[3] ) );

	bn_mat_angles( mat2,
		       atof( words[4] ),
		       atof( words[5] ),
		       atof( words[6] ) );

	MAT_DELTAS( mat3,
		    atof( words[1] ),
		    atof( words[2] ),
		    atof( words[3] ) );

	bn_mat_mul( mat, mat2, mat1 );
	bn_mat_mul2( mat3, mat );

	out_mat( mat, stdout );
	return(0);
    }
    if ( strcmp( words[0], "orient" ) == 0 )  {
	register int i;
	mat_t	mat;
	double	args[8];

	/* Expects tx, ty, tz, rx, ry, rz, [scale]. */
	/* All rotation is done first, then translation */
	/* Note: word[0] and args[0] are the keyword */
	if ( nwords < 6+1 )  return(-1);
	for ( i=1; i<6+1; i++ )
	    args[i] = 0;
	args[7] = 1.0;	/* optional arg, default to 1 */
	for ( i=1; i<nwords; i++ )
	    args[i] = atof( words[i] );
	MAT_IDN( mat );
	bn_mat_angles( mat, args[4], args[5], args[6] );
	MAT_DELTAS( mat, args[1], args[2], args[3] );
	if ( NEAR_ZERO( args[7], VDIVIDE_TOL ) )  {
	    /* Nearly zero, signal error */
	    fprintf(stderr, "Orient scale arg is near zero ('%s')\n",
		    words[7] );
	    return(-1);
	} else {
	    mat[15] = 1 / args[7];
	}
	out_mat( mat, stdout );
	return(0);
    }
    if ( strcmp( words[0], "ae" ) == 0 )  {
	mat_t	mat;
	fastf_t	az, el;

	if ( nwords < 3 )  return(-1);
	/* Expects azimuth, elev, optional twist */
	az = atof(words[1]);
	el = atof(words[2]);
#if 0
	if ( nwords == 3 )
	    twist = 0.0;
	else
	    twist = atof(words[3]);
#endif
	MAT_IDN( mat );
	/* XXX does not take twist, for now XXX */
	bn_mat_ae( mat, az, el );
	out_mat( mat, stdout );
	return(0);
    }
    if ( strcmp( words[0], "arb_rot_pt" ) == 0 )  {
	mat_t	mat;
	point_t	pt1, pt2;
	vect_t	dir;
	fastf_t	ang;

	if ( nwords < 1+3+3+1 )  return(-1);
	/* Expects point1, point2, angle */
	VSET( pt1, atof(words[1]), atof(words[2]), atof(words[3]) );
	VSET( pt2, atof(words[4]), atof(words[5]), atof(words[6]) );
	ang = atof(words[7]) * bn_degtorad;
	VSUB2( dir, pt2, pt2 );
	VUNITIZE(dir);
	MAT_IDN( mat );
	bn_mat_arb_rot( mat, pt1, dir, ang );
	out_mat( mat, stdout );
	return(0);
    }
    if ( strcmp( words[0], "arb_rot_dir" ) == 0 )  {
	mat_t	mat;
	point_t	pt1;
	vect_t	dir;
	fastf_t	ang;

	if ( nwords < 1+3+3+1 )  return(-1);
	/* Expects point1, dir, angle */
	VSET( pt1, atof(words[1]), atof(words[2]), atof(words[3]) );
	VSET( dir, atof(words[4]), atof(words[5]), atof(words[6]) );
	ang = atof(words[7]) * bn_degtorad;
	VUNITIZE(dir);
	MAT_IDN( mat );
	bn_mat_arb_rot( mat, pt1, dir, ang );
	out_mat( mat, stdout );
	return(0);
    }
    if ( strcmp( words[0], "quat" ) == 0 )  {
	mat_t	mat;
	quat_t	quat;

	/* Usage: quat x, y, z, w */
	if ( nwords < 5 ) return -1;
	QSET( quat, atof(words[1]), atof(words[2]),
	      atof(words[3]), atof(words[4]) );

	quat_quat2mat( mat, quat );
	out_mat( mat, stdout);
	return 0;
    }
    if ( strcmp( words[0], "fromto" ) == 0 )  {
	mat_t	mat;
	point_t	cur;
	point_t	next;
	vect_t	from;
	vect_t	to;

	/* Usage: fromto +Z cur_xyz next_xyz */
	if ( nwords < 8 )  return -1;
	if ( strcmp( words[1], "+X" ) == 0 )  {
	    VSET( from, 1, 0, 0 );
	} else if ( strcmp( words[1], "-X" ) == 0 )  {
	    VSET( from, -1, 0, 0 );
	} else if ( strcmp( words[1], "+Y" ) == 0 )  {
	    VSET( from, 0, 1, 0 );
	} else if ( strcmp( words[1], "-Y" ) == 0 )  {
	    VSET( from, 0, -1, 0 );
	} else if ( strcmp( words[1], "+Z" ) == 0 )  {
	    VSET( from, 0, 0, 1 );
	} else if ( strcmp( words[1], "-Z" ) == 0 )  {
	    VSET( from, 0, 0, -1 );
	} else {
	    fprintf(stderr, "fromto '%s' is not +/-XYZ\n", words[1]);
	    return -1;
	}
	VSET( cur, atof(words[2]), atof(words[3]), atof(words[4]) );
	VSET( next, atof(words[5]), atof(words[6]), atof(words[7]) );
	VSUB2( to, next, cur );
	VUNITIZE(to);
	bn_mat_fromto( mat, from, to );
	/* Check to see if it worked. */
	{
	    vect_t	got;

	    MAT4X3VEC( got, mat, from );
	    if ( VDOT( got, to ) < 0.9 )  {
		bu_log("\ntabsub ERROR: At t=%s, bn_mat_fromto failed!\n", chanwords[0] );
		VPRINT("\tfrom", from);
		VPRINT("\tto", to);
		VPRINT("\tgot", got);
	    }
	}
	out_mat( mat, stdout );
	return 0;
    }
    return(-2);		/* Unknown keyword */
}