/* some of the most important stuff in the program */

#define DOT(v1,v2) (v1.x*v2.x+v1.y*v2.y+v1.z*v2.z)
                          /* returns dot product of two vectors */

#define LN2(v)	   (DOT(v,v))
                         /* returns the square of the length of a vector */

#define LEN(v)	   sqrt(LN2(v))
                         /* guess */

#define XZL(v)	   sqrt(v.x*v.x+v.z*v.z)
                         /* returns the component in the xz plane of a vector */

#define SCMLT(sc,vct) vct.x*= sc;vct.y*= sc;vct.z*= sc;vct.l*= sc;
                         /* multiplies a vetor by a scalar */

#define MV(a,b,c,v)   v.x= a;v.y= b;v.z= c;
                         /* makes a vector. wouldn't need this with c++ */

#define SV(t,u,v)  t.x=u.x-v.x;t.y=u.y-v.y;t.z=u.z-v.z;
                         /* subtract vector t=u-v */

#define AV(t,u,v)  t.x=u.x+v.x;t.y=u.y+v.y;t.z=u.z+v.z;
                         /* add vector t=u+v */

#define MTV(v1,m,v2) MV(DOT(m.x,v2),DOT(m.y,v2),DOT(m.z,v2),v1)
                         /* multiply transpose matrix by vector. v1=m*v2 */


#define FACET_COMP(comp,index) data->object.facet.point[index].comp
                         /* get an x, y, or z component of point with index */

#define FACET_MINUS(comp,index1,index2) (FACET_COMP(comp, index1) - FACET_COMP(comp, index2)) 
                         /* subtract two points components */

#define CROSS_PRODUCT(r,v1,v2) r.x = v1.y * v2.z - v1.z * v2.y;\
                                 r.y = v1.z * v2.x - v1.x * v2.z;\
                                 r.z = v1.x * v2.y - v1.y * v2.x;
                         /* cross product of two vectors */

#define NUM_MAX(x,y) (((x) > (y)) ? (x): (y))
                         /* maximum of two numbers */

#define NUM_MIN(x,y) (((x) < (y)) ? (x): (y))
                         /* minimum of two numbers */

#define LEVEL 5/* levels of recursion */
#define RLEV  3/*don't want as many inside the ball, takes forever as it is*/

#define XMIN 0.0
#define XMAX 256.0
#define YMIN  0.0
#define YMAX 256.0
                   /* window size,  virtual units */

#define SCALE  2.0
                   /* magnification factor */