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#ifndef GFXGEOM3D_INCLUDED
#define GFXGEOM3D_INCLUDED
#if !defined(__GNUC__)
# pragma once
#endif
/************************************************************************
Handy 3D geometrical primitives
$Id: geom3d.h 432 2004-11-02 22:55:41Z garland $
************************************************************************/
#include "vec3.h"
namespace gfx
{
//
// Computing properties of triangles
//
template<class Vec>
inline Vec triangle_raw_normal(const Vec& v1, const Vec& v2, const Vec& v3)
{
return cross(v2-v1, v3-v1);
}
template<class Vec>
inline typename Vec::value_type
triangle_area(const Vec& v1,const Vec& v2,const Vec& v3)
{
return 0.5 * norm(triangle_raw_normal(v1, v2, v3));
}
template<class Vec>
inline Vec triangle_normal(const Vec& v1, const Vec& v2, const Vec& v3)
{
Vec n = triangle_raw_normal(v1, v2, v3);
unitize(n);
return n;
}
template<class Vec, class Plane>
inline Plane triangle_plane(const Vec& v1, const Vec& v2, const Vec& v3)
{
Vec n = triangle_normal(v1, v2, v3);
return Plane(n, -(n*v1));
}
template<class Vec, class Plane>
inline Plane triangle_raw_plane(const Vec& v1, const Vec& v2, const Vec& v3)
{
Vec n = triangle_raw_normal(v1, v2, v3);
return Plane(n, -(n*v1));
}
template< class Vec>
inline typename Vec::value_type
triangle_compactness(const Vec& v1, const Vec& v2, const Vec& v3)
{
const double FOUR_ROOT3 = 6.928203230275509;
return FOUR_ROOT3 * triangle_area(v1, v2, v3) /
( norm2(v2 - v1) + norm2(v3 - v2) + norm2(v1 - v3) );
}
//
// Operations with axis-aligned bounding boxes
//
template<class Vec, class List>
void update_bbox(Vec& min, Vec& max, const List& items)
{
typedef typename List::const_iterator iterator;
for(iterator i=items.begin(); i!=items.end(); i++)
{
const Vec& v = *i;
for(int j=0; j<Vec::dim(); j++)
{
if( v[j] < min[j] ) min[j] = v[j];
if( v[j] > max[j] ) max[j] = v[j];
}
}
}
template<class Vec, class List>
void compute_bbox(Vec& min, Vec& max, const List& items)
{
if( items.size()==0 ) min = max = 0;
else min = max = items[0];
update_bbox(min, max, items);
}
template<class Vec>
bool is_inside_bbox(const Vec& p, const Vec& min, Vec& max)
{
for(int i=0; i<Vec::dim(); i++)
if( p[i]<min[i] || p[i]>max[i] )
return false;
return true;
}
template<class Vec>
Vec clamp_to_bbox(Vec p, const Vec& min, const Vec& max)
{
for(int i=0; i<Vec::dim(); i++)
{
if (p[i]<min[i]) p[i]=min[i];
else if (p[i]>max[i]) p[i]=max[i];
}
return p;
}
//
// Computing properties of tetrahedra
//
extern double tetrahedron_determinant(const Vec3& v0, const Vec3& v1,
const Vec3& v2, const Vec3& v3);
extern double tetrahedron_volume(const Vec3& v0, const Vec3& v1,
const Vec3& v2, const Vec3& v3);
} // namespace gfx
// GFXGEOM3D_INCLUDED
#endif
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