73     q->ctr.x = 0.0;  in newquadric()
74     q->ctr.y = 0.0;  in newquadric()
75     q->ctr.z = 0.0;  in newquadric()
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()
126     N->x = (q->mat.a * (pnt->x - q->ctr.x) + q->mat.b * (pnt->y - q->ctr.y) +  in quadric_normal()
127             q->mat.c * (pnt->z - q->ctr.z) + q->mat.d);  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()
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()