pxmlw6n2f/ign-math/examples/triangle_example.cc

81 lines
2.8 KiB
C++

/*
* Copyright (C) 2012-2014 Open Source Robotics Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include <iostream>
#include <ignition/math.hh>
int main(int argc, char **argv)
{
// Create a triangle with the following vertices:
// 1: x = -1, y = 0
// 2: x = 0, y = 1
// 3: x = 1, y = 0
ignition::math::Triangled tri(
ignition::math::Vector2d(-1, 0),
ignition::math::Vector2d(0, 1),
ignition::math::Vector2d(1, 0));
// The individual vertices are accessible through the [] operator
std::cout << "Vertex 1: " << tri[0] << "\n"
<< "Vertex 2: " << tri[1] << "\n"
<< "Vertex 3: " << tri[2] << "\n";
// Each side of the triangle is also accessible via the Side function
std::cout << "Side 1: " << tri.Side(0) << "\n"
<< "Side 2: " << tri.Side(1) << "\n"
<< "Side 3: " << tri.Side(2) << "\n";
// It's also possible to set each vertex individually.
tri.Set(0, ignition::math::Vector2d(-10, 0));
tri.Set(1, ignition::math::Vector2d(0, 20));
tri.Set(2, ignition::math::Vector2d(10, 2));
// Or set all the vertices at once.
tri.Set(ignition::math::Vector2d(-1, 0),
ignition::math::Vector2d(0, 1),
ignition::math::Vector2d(1, 0));
// You can get the perimeter length and area of the triangle
std::cout << "Perimeter=" << tri.Perimeter()
<< " Area=" << tri.Area() << "\n";
// The Contains functions check if a line or point is inside the triangle
if (tri.Contains(ignition::math::Vector2d(0, 0.5)))
std::cout << "Triangle contains the point 0, 0.5\n";
else
std::cout << "Triangle does not contain the point 0, 0.5\n";
// The Intersect function check if a line segment intersects the triangle.
// It also returns the points of intersection
ignition::math::Vector2d pt1, pt2;
if (tri.Intersects(ignition::math::Line2d(-2, 0.5, 2, 0.5), pt1, pt2))
{
std::cout << "A line from (-2, 0.5) to (2, 0.5) intersects "
<< "the triangle at the\nfollowing points:\n"
<< "\t Pt1=" << pt1 << "\n"
<< "\t Pt2=" << pt2 << "\n";
}
else
{
std::cout << "A line from (-2, 0.5) to (2, 0.5) does not intersect "
<< "the triangle\n";
}
// There are more functions in Triangle. Take a look at the API;
// http://ignitionrobotics.org/libraries/ign_mat/api
}