73     q->ctr.x = 0.0;  in newquadric()
91     ro.x = ry->o.x - q->ctr.x;  in quadric_intersect()
95     Aq = (q->mat.a * (rd.x * rd.x)) + (2.0 * q->mat.b * rd.x * rd.y) +  in quadric_intersect()
96          (2.0 * q->mat.c * rd.x * rd.z) + (q->mat.e * (rd.y * rd.y)) +  in quadric_intersect()
99     Bq = 2.0 * ((q->mat.a * ro.x * rd.x) + (q->mat.b * ((ro.x * rd.y) + (rd.x * ro.y))) +  in quadric_intersect()
100                 (q->mat.c * ((ro.x * rd.z) + (rd.x * ro.z))) + (q->mat.d * rd.x) +  in quadric_intersect()
104     Cq = (q->mat.a * (ro.x * ro.x)) + (2.0 * q->mat.b * ro.x * ro.y) +  in quadric_intersect()
105          (2.0 * q->mat.c * ro.x * ro.z) + (2.0 * q->mat.d * ro.x) + (q->mat.e * (ro.y * ro.y)) +  in quadric_intersect()
126     N->x = (q->mat.a * (pnt->x - q->ctr.x) + q->mat.b * (pnt->y - q->ctr.y) +  in quadric_normal()
129     N->y = (q->mat.b * (pnt->x - q->ctr.x) + q->mat.e * (pnt->y - q->ctr.y) +  in quadric_normal()
132     N->z = (q->mat.c * (pnt->x - q->ctr.x) + q->mat.f * (pnt->y - q->ctr.y) +  in quadric_normal()
138         N->x = -N->x;  in quadric_normal()