/src/lib3ds.lib/quat.c
C | 392 lines | 244 code | 55 blank | 93 comment | 24 complexity | f4573c8b6cd92be0f29ec5a8c07d8d70 MD5 | raw file
- /*
- * The 3D Studio File Format Library
- * Copyright (C) 1996-2001 by J.E. Hoffmann <je-h@gmx.net>
- * All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 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 Lesser General Public
- * License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * $Id: quat.c,v 1.5 2001/01/12 10:29:17 jeh Exp $
- */
- #define LIB3DS_EXPORT
- #include <lib3ds/quat.h>
- #include <math.h>
- /*!
- * \defgroup quat Quaternion Mathematics
- *
- * \author J.E. Hoffmann <je-h@gmx.net>
- */
- /*!
- * \typedef Lib3dsQuat
- * \ingroup quat
- */
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_zero(Lib3dsQuat c)
- {
- c[0]=c[1]=c[2]=c[3]=0.0f;
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_identity(Lib3dsQuat c)
- {
- c[0]=c[1]=c[2]=0.0f;
- c[3]=1.0f;
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_copy(Lib3dsQuat dest, Lib3dsQuat src)
- {
- int i;
- for (i=0; i<4; ++i) {
- dest[i]=src[i];
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_axis_angle(Lib3dsQuat c, Lib3dsVector axis, Lib3dsFloat angle)
- {
- Lib3dsDouble omega,s;
- Lib3dsDouble l;
- l=sqrt(axis[0]*axis[0] + axis[1]*axis[1] + axis[2]*axis[2]);
- if (l<LIB3DS_EPSILON) {
- c[0]=c[1]=c[2]=0.0f;
- c[3]=1.0f;
- }
- else {
- omega=-0.5*angle;
- s=sin(omega)/l;
- c[0]=(Lib3dsFloat)s*axis[0];
- c[1]=(Lib3dsFloat)s*axis[1];
- c[2]=(Lib3dsFloat)s*axis[2];
- c[3]=(Lib3dsFloat)cos(omega);
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_neg(Lib3dsQuat c)
- {
- int i;
- for (i=0; i<4; ++i) {
- c[i]=-c[i];
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_abs(Lib3dsQuat c)
- {
- int i;
- for (i=0; i<4; ++i) {
- c[i]=(Lib3dsFloat)fabs(c[i]);
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_cnj(Lib3dsQuat c)
- {
- int i;
- for (i=0; i<3; ++i) {
- c[i]=-c[i];
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_mul(Lib3dsQuat c, Lib3dsQuat a, Lib3dsQuat b)
- {
- c[0]=a[3]*b[0] + a[0]*b[3] + a[1]*b[2] - a[2]*b[1];
- c[1]=a[3]*b[1] + a[1]*b[3] + a[2]*b[0] - a[0]*b[2];
- c[2]=a[3]*b[2] + a[2]*b[3] + a[0]*b[1] - a[1]*b[0];
- c[3]=a[3]*b[3] - a[0]*b[0] - a[1]*b[1] - a[2]*b[2];
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_scalar(Lib3dsQuat c, Lib3dsFloat k)
- {
- int i;
- for (i=0; i<4; ++i) {
- c[i]*=k;
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_normalize(Lib3dsQuat c)
- {
- Lib3dsDouble l,m;
- l=sqrt(c[0]*c[0] + c[1]*c[1] + c[2]*c[2] + c[3]*c[3]);
- if (fabs(l)<LIB3DS_EPSILON) {
- c[0]=c[1]=c[2]=0.0f;
- c[3]=1.0f;
- }
- else {
- int i;
- m=1.0f/l;
- for (i=0; i<4; ++i) {
- c[i]=(Lib3dsFloat)(c[i]*m);
- }
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_inv(Lib3dsQuat c)
- {
- Lib3dsDouble l,m;
- l=sqrt(c[0]*c[0] + c[1]*c[1] + c[2]*c[2] + c[3]*c[3]);
- if (fabs(l)<LIB3DS_EPSILON) {
- c[0]=c[1]=c[2]=0.0f;
- c[3]=1.0f;
- }
- else {
- m=1.0f/l;
- c[0]=(Lib3dsFloat)(-c[0]*m);
- c[1]=(Lib3dsFloat)(-c[1]*m);
- c[2]=(Lib3dsFloat)(-c[2]*m);
- c[3]=(Lib3dsFloat)(c[3]*m);
- }
- }
- /*!
- * \ingroup quat
- */
- Lib3dsFloat
- lib3ds_quat_dot(Lib3dsQuat a, Lib3dsQuat b)
- {
- return(a[0]*b[0] + a[1]*b[1] + a[2]*b[2] + a[3]*b[3]);
- }
- /*!
- * \ingroup quat
- */
- Lib3dsFloat
- lib3ds_quat_squared(Lib3dsQuat c)
- {
- return(c[0]*c[0] + c[1]*c[1] + c[2]*c[2] + c[3]*c[3]);
- }
- /*!
- * \ingroup quat
- */
- Lib3dsFloat
- lib3ds_quat_length(Lib3dsQuat c)
- {
- return((Lib3dsFloat)sqrt(c[0]*c[0] + c[1]*c[1] + c[2]*c[2] + c[3]*c[3]));
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_ln(Lib3dsQuat c)
- {
- Lib3dsDouble om,s,t;
- s=sqrt(c[0]*c[0] + c[1]*c[1] + c[2]*c[2]);
- om=atan2(s,c[3]);
- if (fabs(s)<LIB3DS_EPSILON) {
- t=0.0f;
- }
- else {
- t=om/s;
- }
- {
- int i;
- for (i=0; i<3; ++i) {
- c[i]=(Lib3dsFloat)(c[i]*t);
- }
- c[3]=0.0f;
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_ln_dif(Lib3dsQuat c, Lib3dsQuat a, Lib3dsQuat b)
- {
- Lib3dsQuat invp;
- lib3ds_quat_copy(invp, a);
- lib3ds_quat_inv(invp);
- lib3ds_quat_mul(c, invp, b);
- lib3ds_quat_ln(c);
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_exp(Lib3dsQuat c)
- {
- Lib3dsDouble om,sinom;
- om=sqrt(c[0]*c[0] + c[1]*c[1] + c[2]*c[2]);
- if (fabs(om)<LIB3DS_EPSILON) {
- sinom=1.0f;
- }
- else {
- sinom=sin(om)/om;
- }
- {
- int i;
- for (i=0; i<3; ++i) {
- c[i]=(Lib3dsFloat)(c[i]*sinom);
- }
- c[3]=(Lib3dsFloat)cos(om);
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_slerp(Lib3dsQuat c, Lib3dsQuat a, Lib3dsQuat b, Lib3dsFloat t)
- {
- Lib3dsDouble l;
- Lib3dsDouble om,sinom;
- Lib3dsDouble sp,sq;
- Lib3dsQuat q;
- l=a[0]*b[0] + a[1]*b[1] + a[2]*b[2] + a[3]*b[3];
- if ((1.0+l)>LIB3DS_EPSILON) {
- if (fabs(l)>1.0f) l/=fabs(l);
- om=acos(l);
- sinom=sin(om);
- if (fabs(sinom)>LIB3DS_EPSILON) {
- sp=sin((1.0f-t)*om)/sinom;
- sq=sin(t*om)/sinom;
- }
- else {
- sp=1.0f-t;
- sq=t;
- }
- c[0]=(Lib3dsFloat)(sp*a[0] + sq*b[0]);
- c[1]=(Lib3dsFloat)(sp*a[1] + sq*b[1]);
- c[2]=(Lib3dsFloat)(sp*a[2] + sq*b[2]);
- c[3]=(Lib3dsFloat)(sp*a[3] + sq*b[3]);
- }
- else {
- q[0]=-a[1];
- q[1]=a[0];
- q[2]=-a[3];
- q[3]=a[2];
- sp=sin((1.0-t)*LIB3DS_HALFPI);
- sq=sin(t*LIB3DS_HALFPI);
- c[0]=(Lib3dsFloat)(sp*a[0] + sq*q[0]);
- c[1]=(Lib3dsFloat)(sp*a[1] + sq*q[1]);
- c[2]=(Lib3dsFloat)(sp*a[2] + sq*q[2]);
- c[3]=(Lib3dsFloat)(sp*a[3] + sq*q[3]);
- }
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_squad(Lib3dsQuat c, Lib3dsQuat a, Lib3dsQuat p, Lib3dsQuat q,
- Lib3dsQuat b, Lib3dsFloat t)
- {
- Lib3dsQuat ab;
- Lib3dsQuat pq;
- lib3ds_quat_slerp(ab,a,b,t);
- lib3ds_quat_slerp(pq,p,q,t);
- lib3ds_quat_slerp(c,ab,pq,2*t*(1-t));
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_tangent(Lib3dsQuat c, Lib3dsQuat p, Lib3dsQuat q, Lib3dsQuat n)
- {
- Lib3dsQuat dn,dp,x;
- int i;
- lib3ds_quat_ln_dif(dn, q, n);
- lib3ds_quat_ln_dif(dp, q, p);
- for (i=0; i<4; i++) {
- x[i]=-1.0f/4.0f*(dn[i]+dp[i]);
- }
- lib3ds_quat_exp(x);
- lib3ds_quat_mul(c,q,x);
- }
- /*!
- * \ingroup quat
- */
- void
- lib3ds_quat_dump(Lib3dsQuat q)
- {
- printf("%f %f %f %f\n", q[0], q[1], q[2], q[3]);
- }