86     vector ro;  in quadric_intersect()  local
91     ro.x = ry->o.x - q->ctr.x;  in quadric_intersect()
92     ro.y = ry->o.y - q->ctr.y;  in quadric_intersect()
93     ro.z = ry->o.z - q->ctr.z;  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()
101                 (q->mat.e * ro.y * rd.y) + (q->mat.f * ((ro.y * rd.z) + (rd.y * ro.z))) +  in quadric_intersect()
102                 (q->mat.g * rd.y) + (q->mat.h * ro.z * rd.z) + (q->mat.i * rd.z));  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()
106          (2.0 * q->mat.f * ro.y * ro.z) + (2.0 * q->mat.g * ro.y) + (q->mat.h * (ro.z * ro.z)) +  in quadric_intersect()
107          (2.0 * q->mat.i * ro.z) + q->mat.j;  in quadric_intersect()