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/*=========================================================================
Program: Visualization Toolkit
Module: TestTriangle.cxx
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
// .NAME
// .SECTION Description
// this program tests the Triangle
#include "vtkNew.h"
#include "vtkPoints.h"
#include "vtkSmartPointer.h"
#include "vtkTriangle.h"
#include <limits>
template <class A>
bool fuzzyCompare(A a, A b)
{
return fabs(a - b) < std::numeric_limits<A>::epsilon();
}
int TestTriangle(int, char*[])
{
// three vertices making a triangle
double pnt0[3] = { 0, 2, 0 };
double pnt1[3] = { 4, 2, 0 };
double pnt2[3] = { 0, 6, 0 };
// points to be tested against the triangle
double pnts[][3] = {
// squared error tolerance
// = 0.0001 * 0.0001 = 0.00000001
// outside the triangle
{ 0, 1.999, 0 },
{ -0.001, 2, 0 },
{ 4, 1.999, 0 },
{ 4, 2.001, 0 },
{ 4.001, 2, 0 },
{ 0, 6.001, 0 },
{ 0.001, 6, 0 },
{ -0.001, 6, 0 },
{ -0.001, 2.001, 0 },
{ -0.001, 1.999, 0 },
{ 0.001, 1.999, 0 },
{ 4.001, 2.001, 0 },
{ 4.001, 1.999, 0 },
{ 3.999, 1.999, 0 },
{ -0.001, 5.999, 0 },
{ -0.001, 6.001, 0 },
{ 0.001, 6.001, 0 },
// inside the triangle
{ 0, 2.001, 0 },
{ 0.001, 2, 0 },
{ 0.001, 2.001, 0 },
{ 3.999, 2.001, 0 },
{ 3.999, 2, 0 },
{ 0, 5.999, 0 },
{ 0.001, 5.999, 0 },
{ 0, 2, 0 },
{ 4, 2, 0 },
{ 0, 6, 0 },
{ 2, 2, 0 },
{ 2, 4, 0 },
{ 0, 4, 0 },
{ 1.333, 3.333, 0 },
};
int inside;
for (int i = 0; i < 31; i++)
{
inside = vtkTriangle::PointInTriangle(pnts[i], pnt0, pnt1, pnt2, 0.00000001);
if (inside && i < 17)
{
cerr << "ERROR: point #" << i
<< ", an outside-point, considered to be inside the triangle!!!" << endl;
cerr << "Squared error tolerance: 0.00000001" << endl;
return EXIT_FAILURE;
}
else if (!inside && i > 16)
{
cerr << "ERROR: point #" << i
<< ", an inside-point, considered to be outside the triangle!!!" << endl;
cerr << "Squared error tolerance: 0.00000001" << endl;
return EXIT_FAILURE;
}
}
cout << "Passed: 17 points outside and 14 points inside the triangle." << endl;
vtkSmartPointer<vtkTriangle> triangle = vtkSmartPointer<vtkTriangle>::New();
triangle->GetPoints()->SetPoint(0, 0.0, 0.0, 0.0);
triangle->GetPoints()->SetPoint(1, 1.0, 0.0, 0.0);
triangle->GetPoints()->SetPoint(2, 0.0, 1.0, 0.0);
double area = triangle->ComputeArea();
if (!fuzzyCompare(area, 0.5))
{
cerr << "ERROR: triangle area is " << area << ", should be 0.5" << endl;
return EXIT_FAILURE;
}
// Testing degenerated triangle
double pntDeg0[3] = { 0, 0, -10 };
double pntDeg1[3] = { 0, 0, 0 };
double pntDeg2[3] = { 0, 0, 10 };
vtkNew<vtkTriangle> triangleDeg;
triangleDeg->GetPoints()->SetPoint(0, pntDeg0);
triangleDeg->GetPoints()->SetPoint(1, pntDeg1);
triangleDeg->GetPoints()->SetPoint(2, pntDeg2);
double p1[3] = { 0, 1, 1 };
double p2[3] = { 0, -1, 1 };
double t;
double x[3];
double pcoords[3];
int subId;
double dEpsilon = std::numeric_limits<double>::epsilon();
if (triangleDeg->IntersectWithLine(p1, p2, dEpsilon, t, x, pcoords, subId) != 1 || x[0] != 0 ||
x[1] != 0 || x[2] != 1 || t != 0.5 || pcoords[0] != 1.1 || pcoords[1] != 0.55 ||
pcoords[2] != 0)
{
cerr << "Error while intersecting degenerated triangle" << endl;
return EXIT_FAILURE;
}
double p1b[3] = { 0, 1, 10.001 };
double p2b[3] = { 0, -1, 10.001 };
if (triangleDeg->IntersectWithLine(p1b, p2b, dEpsilon, t, x, pcoords, subId) != 0)
{
cerr << "Error while intersecting degenerated triangle" << endl;
return EXIT_FAILURE;
}
// Testing intersection of triangle with coplanar line
// Build triangle
double pt0[3] = { 0, 0, 0 };
double pt1[3] = { 0, 10, 0 };
double pt2[3] = { 0, 0, 10 };
vtkNew<vtkTriangle> coplanarTriangle;
coplanarTriangle->GetPoints()->SetPoint(0, pt0);
coplanarTriangle->GetPoints()->SetPoint(1, pt1);
coplanarTriangle->GetPoints()->SetPoint(2, pt2);
// Define line extremities with first extremity inside
double ext1[3] = { 0, 1, 5 };
double ext2[3] = { 0, 11, 5 };
int res = coplanarTriangle->IntersectWithLine(ext1, ext2, dEpsilon, t, x, pcoords, subId);
// Verify correct output values
if (res != 1)
{
cerr << "Line intersection with coplanar triangle not detected" << endl;
return EXIT_FAILURE;
}
else if (x[0] != 0 || x[1] != 1 || x[2] != 5 || t != 0.0 || pcoords[0] != 0.1 ||
pcoords[1] != 0.5 || pcoords[2] != 0.0)
{
cerr << "Output coordinates of intersecting point incorrect" << endl;
return EXIT_FAILURE;
}
// Define line extremities with first extremity outside
ext1[0] = 0;
ext1[1] = -1;
ext1[2] = 5;
ext2[0] = 0;
ext2[1] = 9;
ext2[2] = 5;
res = coplanarTriangle->IntersectWithLine(ext1, ext2, dEpsilon, t, x, pcoords, subId);
// Verify correct output values
if (res != 1)
{
cerr << "Line intersection with coplanar triangle not detected" << endl;
return EXIT_FAILURE;
}
else if (x[0] != 0 || x[1] != 0 || x[2] != 5 || t != 0.1 || pcoords[0] != 0.0 ||
pcoords[1] != 0.5 || pcoords[2] != 0.0)
{
cerr << "Output coordinates of intersecting point incorrect" << endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
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