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//==================================================================
// Copyright 2002, softSurfer (www.softsurfer.com)
// This code may be freely used and modified for any purpose
// providing that this copyright notice is included with it.
// SoftSurfer makes no warranty for this code, and cannot be held
// liable for any real or imagined damage resulting from it's use.
// Users of this code must verify correctness for their application.
//==================================================================
#include "point.h"
#include "vector.h"
//------------------------------------------------------------------
// vtest - test Vector class methods
//------------------------------------------------------------------
main()
{
double a, c[3];
Vector u, v(1), w(0,1);
Vector vx[3];
// output preset coords of v and w
cout << "Initial v = " << v << endl;
cout << "Initial w = " << w << endl;
cout << endl;
// input new values for vectors v and w
// to test ">>" and "<<" Vector operators
cout << "Input v = '(x,y,z)': ";
cin >> v;
cout << "v = " << v << endl;
cout << "Input w = '(x,y,z)': ";
cin >> w;
cout << "w = " << w << endl;
cout << endl;
// test operators
u = -v; cout << "-v = " << u << endl;
u = ~v; cout << "~v = " << u << endl;
u = 2*v; cout << "2*v = " << u << endl;
u = v + w; cout << "v + w = " << u << endl;
u = (v + w)/2; cout << "(v + w)/2 = " << u << endl;
u = v - w; cout << "v - w = " << u << endl;
u = (v - w)*0.5; cout << "(v - w)*0.5 = " << u << endl;
u = v ^ w; cout << "v ^ w = " << u << endl;
a = v * w; cout << "v * w = " << a << endl;
a = v | w; cout << "v | w = " << a << endl;
a = ~v * w; cout << "~v * w = " << a << endl;
cout << endl;
// test functions
c[0]= 0.5; c[1]= 0.5; cout << "c[]= {" << c[0] << ", " << c[1] << "}\n";
vx[0]= v; vx[1]= w; cout << "vx[]= {" << vx[0] << ", " << vx[1] << "}\n";
u = sum(2,c,vx); cout << "sum(2,c,vx) = " << u << endl;
u = v.len2(); cout << "v.len2() = " << u << endl;
u = v.len(); cout << "v.len() = " << u << endl;
v.normalize(); cout << "v.normalize() = " << v << endl;
w.normalize(); cout << "w.normalize() = " << w << endl;
cout << endl;
// check that a few identities are always true
int cnt=0, errs=0;
Vector u0, uinc(2,0,-2);
Vector v0, vinc(1,1,1);
Vector w0, winc(0.2, 0.2, 0.0);
Vector x, x0(-1,-2,-3), xinc(0.5,-0.5,0.1);
double dl, dr; // left and right side doubles
Vector vl, vr; // left and right side vectors
double er, e=0.000000000001; // allow small float error e
for (u=u0; u.x < 7; u+=uinc)
for (v=v0; v.x < 11; v+=vinc)
for (w=w0; w.x < 1.1; w+=winc) {
++cnt;
// Triple product
dl = u * (v ^ w);
dr = (u ^ v) * w;
er = abs(dl-dr);
if (er > e) { // identity fails > e
++errs; // count errors
cout << "Error: err= " << er << endl;
}
++cnt;
// Left Association of Cross Product
vl = (u ^ v) ^ w;
vr = (u * w) * v - (v * w) * u;
er = (vl-vr).len();
if (er > e) { // identity fails > e
++errs; // count errors
cout << "Error: err= " << er << endl;
}
++cnt;
// Lagrange Identity
for (x=x0; x.x < 1.1; x+=xinc) {
dl = (u ^ v) * (w ^ x);
dr = (u * w) * (v * x) - (v * w) * (u * x);
er = abs(dl-dr);
if (er > e) { // identity fails > e
++errs; // count errors
cout << "Error: err= " << er << endl;
}
++cnt;
}
}
cout << "Did " << cnt << " identity chks. Had " << errs << " errors\n";
}
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