triangle_3d.inl

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
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 *  Copyright (C) 2004-2011 the Initial Developer.
 *  All Rights Reserved.
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 *
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 *  GNU General Public License Version 2 or later (the GPL), in which case the 
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 *  *** END LICENSE INFORMATION ***
 */
 
 
 
#ifndef LASS_GUARDIAN_OF_INCLUSION_PRIM_SIMPLE_TRIANGLE_3D_INL
#define LASS_GUARDIAN_OF_INCLUSION_PRIM_SIMPLE_TRIANGLE_3D_INL
 
#include "prim_common.h"
#include "triangle_3d.h"
 
namespace lass
{
namespace prim
{
 
/** constructs an empty triangle.
 *  all vertices are (0, 0) and thus equal.
 */
template <typename T>
Triangle3D<T>::Triangle3D()
{
}
 
 
 
/** Constructs a triangle through three points in positive sequence.
 */
template <typename T>
Triangle3D<T>::Triangle3D(const TPoint& iA, const TPoint& iB, const TPoint& iC)
{
    vertices_[0] = iA;
    vertices_[1] = iB;
    vertices_[2] = iC;
}
 
 
 
/** @copydoc SimplePolygon3D::operator[]
 */
template <typename T>
const typename Triangle3D<T>::TPoint&
Triangle3D<T>::operator[](size_t iIndexOfVertex) const
{
    LASS_ASSERT(isInRange(iIndexOfVertex));
    return vertices_[iIndexOfVertex];
}
 
 
 
/** @copydoc SimplePolygon3D::operator[]
 */
template <typename T>
typename Triangle3D<T>::TPoint&
Triangle3D<T>::operator[](size_t iIndexOfVertex)
{
    LASS_ASSERT(isInRange(iIndexOfVertex));
    return vertices_[iIndexOfVertex];
}
 
 
 
/** @copydoc SimplePolygon3D::at
 */
template <typename T>
const typename Triangle3D<T>::TPoint&
Triangle3D<T>::at(int iIndexOfVertex) const
{
    const int i = num::mod(iIndexOfVertex, static_cast<unsigned>(size_));
    LASS_ASSERT(isInRange(i));
    return vertices_[i];
}
 
 
 
/** @copydoc SimplePolygon3D::at
 */
template <typename T>
typename Triangle3D<T>::TPoint&
Triangle3D<T>::at(int iIndexOfVertex)
{
    const int i = num::mod(iIndexOfVertex, static_cast<unsigned>(size_));
    LASS_ASSERT(isInRange(i));
    return vertices_[i];
}
 
 
 
/** @copydoc SimplePolygon3D::edge
 */
template <typename T>
const typename Triangle3D<T>::TLineSegment
Triangle3D<T>::edge(int iIndexOfTailVertex) const
{
    return TLineSegment(at(iIndexOfTailVertex), at(iIndexOfTailVertex + 1));
}
 
 
 
/** @copydoc SimplePolygon3D::vector
 */
template <typename T>
const typename Triangle3D<T>::TVector
Triangle3D<T>::vector(int iIndexOfTailVertex) const
{
    return at(iIndexOfTailVertex + 1) - at(iIndexOfTailVertex);
}
 
 
 
/** @copydoc SimplePolygon3D::plane
 */
template <typename T>
const typename Triangle3D<T>::TPlane
Triangle3D<T>::plane() const
{
    return TPlane(vertices_[0], vertices_[1], vertices_[2]);
}
 
 
 
/** @copydoc SimplePolygon3D::isEmpty
 *  @par Triangle specific:
 *      if all vertices are equal, we assume the triangle is empty
 */
template <typename T>
bool Triangle3D<T>::isEmpty() const
{
    return vertices_[0] == vertices_[1] && vertices_[0] == vertices_[2];
}
 
 
 
/** @copydoc SimplePolygon3D::size
 */
template <typename T>
size_t Triangle3D<T>::size() const
{
    return size_;
}
 
 
 
/** returns squared area of triangle to avoid the square root.
 *  @return num::sqr(area()) but faster :)
 */
template <typename T>
const typename Triangle3D<T>::TValue
Triangle3D<T>::squaredArea() const
{
    LASS_ASSERT(size_ == 3);
    return cross(vertices_[1] - vertices_[0], vertices_[2] - vertices_[0]).squaredNorm() / 4;
}
 
 
 
/** @copydoc SimplePolygon3D::area
 */
template <typename T>
const typename Triangle3D<T>::TValue
Triangle3D<T>::area() const
{
    return num::sqrt(squaredArea());
}
 
 
 
/** @copydoc SimplePolygon3D::perimeter
 */
template <typename T>
const typename Triangle3D<T>::TValue
Triangle3D<T>::perimeter() const
{
    return distance(vertices_[0], vertices_[1]) +
           distance(vertices_[1], vertices_[2]) +
           distance(vertices_[2], vertices_[0]);
}
 
 
 
/** @copydoc SimplePolygon3D::vertexCentroid
 */
template <typename T>
const typename Triangle3D<T>::TPointH
Triangle3D<T>::vertexCentroid() const
{
    TPointH result = vertices_[0] + vertices_[1] + vertices_[2];
    return result;
}
 
 
 
/** @copydoc SimplePolygon3D::surfaceCentroid
 */
template <typename T> inline
const typename Triangle3D<T>::TPointH
Triangle3D<T>::surfaceCentroid() const
{
    return vertexCentroid();
}
 
 
 
/** @copydoc SimplePolygon3D::isSimple
 *  @par Triangle specific:
 *      A triangle is always simple
 */
template <typename T>
bool Triangle3D<T>::isSimple() const
{
    return true;
}
 
 
 
/** @copydoc SimplePolygon3D::isConvex
 *  @par Triangle specific:
 *      A triangle is always convex
 */
template <typename T>
bool Triangle3D<T>::isConvex() const
{
    return true;
}
 
 
 
/** @copydoc SimplePolygon3D::isReflex
 *  @par Triangle specific:
 *  A triangle never has reflex vertices
 */
template <typename T>
bool Triangle3D<T>::isReflex(int /*iIndexOfVertex*/) const
{
    return false;
}
 
 
 
// --- private -------------------------------------------------------------------------------------
 
/** return if index of vertex is in range of the std::vector
 */
template <typename T>
bool Triangle3D<T>::isInRange(size_t iIndexOfVertex) const
{
    return iIndexOfVertex < size_;
}
 
 
 
// --- free ----------------------------------------------------------------------------------------
 
/** @relates lass::prim::Triangle3D
 */
template <typename T>
io::XmlOStream& operator<<(io::XmlOStream& ioOStream, const Triangle3D<T>& iTriangle)
{
    LASS_ENFORCE_STREAM(ioOStream) << "<Triangle3D>\n";
    for (unsigned i = 0; i < 3; ++i)
    {
        ioOStream << "<vertex id='" << i << "'>" << iTriangle[i] << "</vertex>\n";
    }
    ioOStream << "</Triangle3D>\n";
    return ioOStream;
}
 
 
 
/** @relates lass::prim::Triangle3D
 */
template <typename T>
std::ostream& operator<<(std::ostream& ioOStream, const Triangle3D<T>& iTriangle)
{
    LASS_ENFORCE_STREAM(ioOStream) 
        << "{" << iTriangle[0] << ", " << iTriangle[1] << ", " << iTriangle[2] << "}";
    return ioOStream;
}
 
 
 
}
 
}
 
#endif
 
// EOF