75     q->ctr.z = 0.0;  in newquadric()
93     ro.z = ry->o.z - q->ctr.z;  in quadric_intersect()
96          (2.0 * q->mat.c * rd.x * rd.z) + (q->mat.e * (rd.y * rd.y)) +  in quadric_intersect()
97          (2.0 * q->mat.f * rd.y * rd.z) + (q->mat.h * (rd.z * rd.z));  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()
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()
127             q->mat.c * (pnt->z - q->ctr.z) + q->mat.d);  in quadric_normal()
130             q->mat.f * (pnt->z - q->ctr.z) + q->mat.g);  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()
133             q->mat.h * (pnt->z - q->ctr.z) + q->mat.i);  in quadric_normal()
140         N->z = -N->z;  in quadric_normal()