}
}
+void AngleVectorsDuke3DFLU (const vec3_t angles, vec3_t forward, vec3_t left, vec3_t up, double maxShearAngle)
+{
+ double angle, sr, sy, cr, cy;
+ double sxx, sxz, szx, szz;
+ double cosMaxShearAngle = cos(maxShearAngle * (M_PI*2 / 360));
+ double tanMaxShearAngle = tan(maxShearAngle * (M_PI*2 / 360));
+
+ angle = angles[YAW] * (M_PI*2 / 360);
+ sy = sin(angle);
+ cy = cos(angle);
+ angle = angles[PITCH] * (M_PI*2 / 360);
+
+ // We will calculate a shear matrix pitch = [[sxx sxz][szx szz]].
+
+ if (fabs(cos(angle)) > cosMaxShearAngle)
+ {
+ // Pure shear. Keep the original sign of the coefficients.
+ sxx = 1;
+ sxz = 0;
+ szx = -tan(angle);
+ szz = 1;
+ // Covering angle per screen coordinate:
+ // d/dt arctan((sxz + t*szz) / (sxx + t*szx)) @ t=0
+ // d_angle = det(S) / (sxx*sxx + szx*szx)
+ // = 1 / (1 + tan^2 angle)
+ // = cos^2 angle.
+ }
+ else
+ {
+ // A mix of shear and rotation. Implementation-wise, we're
+ // looking at a capsule, and making the screen surface
+ // tangential to it... and if we get here, we're looking at the
+ // two half-spheres of the capsule (and the cylinder part is
+ // handled above).
+ double x, y, h, t, d, f;
+ h = tanMaxShearAngle;
+ x = cos(angle);
+ y = sin(angle);
+ t = h * fabs(y) + sqrt(1 - (h * x) * (h * x));
+ sxx = x * t;
+ sxz = y * t - h * (y > 0 ? 1.0 : -1.0);
+ szx = -y * t;
+ szz = x * t;
+ // BUT: keep the amount of a sphere we see in pitch direction
+ // invariant.
+ // Covering angle per screen coordinate:
+ // d_angle = det(S) / (sxx*sxx + szx*szx)
+ d = (sxx * szz - sxz * szx) / (sxx * sxx + szx * szx);
+ f = cosMaxShearAngle * cosMaxShearAngle / d;
+ sxz *= f;
+ szz *= f;
+ }
+
+ if (forward)
+ {
+ forward[0] = sxx*cy;
+ forward[1] = sxx*sy;
+ forward[2] = szx;
+ }
+ if (left || up)
+ {
+ if (angles[ROLL])
+ {
+ angle = angles[ROLL] * (M_PI*2 / 360);
+ sr = sin(angle);
+ cr = cos(angle);
+ if (left)
+ {
+ left[0] = sr*sxz*cy+cr*-sy;
+ left[1] = sr*sxz*sy+cr*cy;
+ left[2] = sr*szz;
+ }
+ if (up)
+ {
+ up[0] = cr*sxz*cy+-sr*-sy;
+ up[1] = cr*sxz*sy+-sr*cy;
+ up[2] = cr*szz;
+ }
+ }
+ else
+ {
+ if (left)
+ {
+ left[0] = -sy;
+ left[1] = cy;
+ left[2] = 0;
+ }
+ if (up)
+ {
+ up[0] = sxz*cy;
+ up[1] = sxz*sy;
+ up[2] = szz;
+ }
+ }
+ }
+}
+
// LordHavoc: calculates pitch/yaw/roll angles from forward and up vectors
void AnglesFromVectors (vec3_t angles, const vec3_t forward, const vec3_t up, qboolean flippitch)
{