--- /dev/null
+/*
+ * 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 1.6 2004/11/20 08:31:31 efalk 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
+ */
+
+
+/*!
+ * Clear a quaternion.
+ * \ingroup quat
+ */
+void
+lib3ds_quat_zero(Lib3dsQuat c)
+{
+ c[0]=c[1]=c[2]=c[3]=0.0f;
+}
+
+
+/*!
+ * Set a quaternion to Identity
+ * \ingroup quat
+ */
+void
+lib3ds_quat_identity(Lib3dsQuat c)
+{
+ c[0]=c[1]=c[2]=0.0f;
+ c[3]=1.0f;
+}
+
+
+/*!
+ * Copy a quaternion.
+ * \ingroup quat
+ */
+void
+lib3ds_quat_copy(Lib3dsQuat dest, Lib3dsQuat src)
+{
+ int i;
+ for (i=0; i<4; ++i) {
+ dest[i]=src[i];
+ }
+}
+
+
+/*!
+ * Compute a quaternion from axis and angle.
+ *
+ * \param c Computed quaternion
+ * \param axis Rotation axis
+ * \param angle Angle of rotation, radians.
+ *
+ * \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);
+ }
+}
+
+
+/*!
+ * Negate a quaternion
+ *
+ * \ingroup quat
+ */
+void
+lib3ds_quat_neg(Lib3dsQuat c)
+{
+ int i;
+ for (i=0; i<4; ++i) {
+ c[i]=-c[i];
+ }
+}
+
+
+/*!
+ * Compute the absolute value of a quaternion
+ *
+ * \ingroup quat
+ */
+void
+lib3ds_quat_abs(Lib3dsQuat c)
+{
+ int i;
+ for (i=0; i<4; ++i) {
+ c[i]=(Lib3dsFloat)fabs(c[i]);
+ }
+}
+
+
+/*!
+ * Compute the conjugate of a quaternion
+ *
+ * \ingroup quat
+ */
+void
+lib3ds_quat_cnj(Lib3dsQuat c)
+{
+ int i;
+ for (i=0; i<3; ++i) {
+ c[i]=-c[i];
+ }
+}
+
+
+/*!
+ * Multiply two quaternions.
+ *
+ * \param c Result
+ * \param a,b Inputs
+ * \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];
+}
+
+
+/*!
+ * Multiply a quaternion by a scalar.
+ *
+ * \ingroup quat
+ */
+void
+lib3ds_quat_scalar(Lib3dsQuat c, Lib3dsFloat k)
+{
+ int i;
+ for (i=0; i<4; ++i) {
+ c[i]*=k;
+ }
+}
+
+
+/*!
+ * Normalize a quaternion.
+ *
+ * \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);
+ }
+ }
+}
+
+
+/*!
+ * Compute the inverse of a quaternion.
+ *
+ * \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);
+ }
+}
+
+
+/*!
+ * Compute the dot-product of a quaternion.
+ *
+ * \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]);
+}
+
projects / summerhack / blobdiff