Show eulerangles.c syntax highlighted
/**** EulerAngles.c - Convert Euler angles to/from matrix or quat ****/
/* Ken Shoemake, 1993 */
#include <math.h>
#include <float.h>
#include "eulerangles.h"
EulerAngles Eul_(float ai, float aj, float ah, int order)
{
EulerAngles ea;
ea.x = ai; ea.y = aj; ea.z = ah;
ea.w = order;
return (ea);
}
/* Construct quaternion from Euler angles (in radians). */
Quat Eul_ToQuat (EulerAngles ea)
{
Quat qu;
double a[3], ti, tj, th, ci, cj, ch, si, sj, sh, cc, cs, sc, ss;
int i,j,k,h,n,s,f;
EulGetOrd(ea.w,i,j,k,h,n,s,f);
if (f==EulFrmR) {float t = ea.x; ea.x = ea.z; ea.z = t;}
if (n==EulParOdd) ea.y = -ea.y;
ti = ea.x*0.5; tj = ea.y*0.5; th = ea.z*0.5;
ci = cos(ti); cj = cos(tj); ch = cos(th);
si = sin(ti); sj = sin(tj); sh = sin(th);
cc = ci*ch; cs = ci*sh; sc = si*ch; ss = si*sh;
if (s==EulRepYes) {
a[i] = cj*(cs + sc); /* Could speed up with */
a[j] = sj*(cc + ss); /* trig identities. */
a[k] = sj*(cs - sc);
qu.w = cj*(cc - ss);
} else {
a[i] = cj*sc - sj*cs;
a[j] = cj*ss + sj*cc;
a[k] = cj*cs - sj*sc;
qu.w = cj*cc + sj*ss;
}
if (n==EulParOdd) a[j] = -a[j];
qu.x = a[X]; qu.y = a[Y]; qu.z = a[Z];
return (qu);
}
/* Construct matrix from Euler angles (in radians). */
void Eul_ToHMatrix(EulerAngles ea, HMatrix M)
{
double ti, tj, th, ci, cj, ch, si, sj, sh, cc, cs, sc, ss;
int i,j,k,h,n,s,f;
EulGetOrd(ea.w,i,j,k,h,n,s,f);
if (f==EulFrmR) {float t = ea.x; ea.x = ea.z; ea.z = t;}
if (n==EulParOdd) {ea.x = -ea.x; ea.y = -ea.y; ea.z = -ea.z;}
ti = ea.x; tj = ea.y; th = ea.z;
ci = cos(ti); cj = cos(tj); ch = cos(th);
si = sin(ti); sj = sin(tj); sh = sin(th);
cc = ci*ch; cs = ci*sh; sc = si*ch; ss = si*sh;
if (s==EulRepYes) {
M[i][i] = cj; M[i][j] = sj*si; M[i][k] = sj*ci;
M[j][i] = sj*sh; M[j][j] = -cj*ss+cc; M[j][k] = -cj*cs-sc;
M[k][i] = -sj*ch; M[k][j] = cj*sc+cs; M[k][k] = cj*cc-ss;
} else {
M[i][i] = cj*ch; M[i][j] = sj*sc-cs; M[i][k] = sj*cc+ss;
M[j][i] = cj*sh; M[j][j] = sj*ss+cc; M[j][k] = sj*cs-sc;
M[k][i] = -sj; M[k][j] = cj*si; M[k][k] = cj*ci;
}
M[W][X]=M[W][Y]=M[W][Z]=M[X][W]=M[Y][W]=M[Z][W]=0.0; M[W][W]=1.0;
}
/* Convert matrix to Euler angles (in radians). */
EulerAngles Eul_FromHMatrix(HMatrix M, int order)
{
EulerAngles ea;
int i,j,k,h,n,s,f;
EulGetOrd(order,i,j,k,h,n,s,f);
if (s==EulRepYes) {
double sy = sqrt(M[i][j]*M[i][j] + M[i][k]*M[i][k]);
if (sy > 16*FLT_EPSILON) {
ea.x = atan2(M[i][j], M[i][k]);
ea.y = atan2(sy, M[i][i]);
ea.z = atan2(M[j][i], -M[k][i]);
} else {
ea.x = atan2(-M[j][k], M[j][j]);
ea.y = atan2(sy, M[i][i]);
ea.z = 0;
}
} else {
double cy = sqrt(M[i][i]*M[i][i] + M[j][i]*M[j][i]);
if (cy > 16*FLT_EPSILON) {
ea.x = atan2(M[k][j], M[k][k]);
ea.y = atan2(-M[k][i], cy);
ea.z = atan2(M[j][i], M[i][i]);
} else {
ea.x = atan2(-M[j][k], M[j][j]);
ea.y = atan2(-M[k][i], cy);
ea.z = 0;
}
}
if (n==EulParOdd) {ea.x = -ea.x; ea.y = - ea.y; ea.z = -ea.z;}
if (f==EulFrmR) {float t = ea.x; ea.x = ea.z; ea.z = t;}
ea.w = order;
return (ea);
}
/* Convert quaternion to Euler angles (in radians). */
EulerAngles Eul_FromQuat(Quat q, int order)
{
HMatrix M;
double Nq = q.x*q.x+q.y*q.y+q.z*q.z+q.w*q.w;
double s = (Nq > 0.0) ? (2.0 / Nq) : 0.0;
double xs = q.x*s, ys = q.y*s, zs = q.z*s;
double wx = q.w*xs, wy = q.w*ys, wz = q.w*zs;
double xx = q.x*xs, xy = q.x*ys, xz = q.x*zs;
double yy = q.y*ys, yz = q.y*zs, zz = q.z*zs;
M[X][X] = 1.f - (yy + zz); M[X][Y] = xy - wz; M[X][Z] = xz + wy;
M[Y][X] = xy + wz; M[Y][Y] = 1.f - (xx + zz); M[Y][Z] = yz - wx;
M[Z][X] = xz - wy; M[Z][Y] = yz + wx; M[Z][Z] = 1.f - (xx + yy);
M[W][X]=M[W][Y]=M[W][Z]=M[X][W]=M[Y][W]=M[Z][W]=0.f; M[W][W]=1.f;
return (Eul_FromHMatrix(M, order));
}
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