#include "math.h"
#include "plot.h"

void settran(theta,phi)
double theta,phi;
{
double ct,cp,st,sp;
ct = cos(theta); st = sin(theta);
cp = cos(phi); sp = sin(phi);
m1 = ct; m2 = st;
m3 = st*sp; m4 = ct*sp; m5 = cp;
}

void initialmask (p,n)
Gpoint *p;
int n;
{
int i;
/*
 *    Initialize mask and mask size.
 */
for (i=0; i<n; i++) top[i] = bottom[i] = p[i];
topn = bottomn = n;
}

void transform (px,py,pz,p,n)
double *px,*py,*pz;
Gpoint *p;
int n;
{
/*
 *   Transform the (x,y,z) coordinates to (x",y") coords.
 */
int i;
for (i=0; i<n; i++)
  {
    p[i].x = px[i]*m1 - py[i]*m2;
    p[i].y = px[i]*m3 + py[i]*m4 + pz[i]*m5;
  }
}

int copyvec (a,b,n)
Gpoint *a,*b;
int n;
{
int i,k=1;
b[0] = a[0];
for (i=1; i<n; i++) 
  if (b[i].x != b[i-1].x)
    { b[i] = a[i]; k++; }
return (k);
}