ResInsight/Fwk/VizFwk/LibGeometry/cvfPrimitiveTests.cpp
Magne Sjaastad 486f383de7 Integrated changes for framework
Pdm fields can contain a forward declared Pdm object without the include
file
VizFwk: Added VertexColoring shader to be able to use per vertex color
used from drawableGeo::setColorArray()
2014-04-11 11:06:42 +02:00

107 lines
3.6 KiB
C++

//##################################################################################################
//
// Custom Visualization Core library
// Copyright (C) Ceetron Solutions AS
//
// This library may be used under the terms of either the GNU General Public License or
// the GNU Lesser General Public License as follows:
//
// GNU General Public License Usage
// This library is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.
//
// See the GNU General Public License at <<http://www.gnu.org/licenses/gpl.html>>
// for more details.
//
// GNU Lesser General Public License Usage
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.
//
// See the GNU Lesser General Public License at <<http://www.gnu.org/licenses/lgpl-2.1.html>>
// for more details.
//
//##################################################################################################
#include "cvfBase.h"
#include "cvfPrimitiveTests.h"
#include <limits>
namespace cvf {
//==================================================================================================
///
/// \class cvf::PrimitiveTests
/// \ingroup Geometry
///
///
///
//==================================================================================================
//--------------------------------------------------------------------------------------------------
/// Calculate intersection between the lines p1p2 and p3p4
//--------------------------------------------------------------------------------------------------
bool PrimitiveTests::intersectLines(const Vec2d& p1, const Vec2d& p2, const Vec2d& p3, const Vec2d& p4, Vec2d* isect)
{
// See Paul Bourke, Intersection point of two lines in 2 dimensions
const double epsilon = std::numeric_limits<double>::epsilon();
const double denom = (p4.y()-p3.y())*(p2.x()-p1.x()) - (p4.x()-p3.x())*(p2.y()-p1.y());
const double numera = (p4.x()-p3.x())*(p1.y()-p3.y()) - (p4.y()-p3.y())*(p1.x()-p3.x());
const double numerb = (p2.x()-p1.x())*(p1.y()-p3.y()) - (p2.y()-p1.y())*(p1.x()-p3.x());
// Are the lines coincident?
if (cvf::Math::abs(numera) < epsilon &&
cvf::Math::abs(numerb) < epsilon &&
cvf::Math::abs(denom) < epsilon)
{
isect->x() = (p1.x() + p2.x()) / 2;
isect->y() = (p1.y() + p2.y()) / 2;
return true;
}
// Are the lines parallel?
if (cvf::Math::abs(denom) < epsilon)
{
isect->setZero();
return false;
}
const double ta = numera/denom;
// const double tb = numerb/denom;
//
// // Is the intersection along the the segments ?
// if (ta < 0 || ta > 1 || tb < 0 || tb > 1)
// {
// isect->setZero();
// return false;
// }
isect->x() = p1.x() + ta * (p2.x() - p1.x());
isect->y() = p1.y() + ta * (p2.y() - p1.y());
return true;
}
} // namespace cvf