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/* SPDX-License-Identifier: GPL-2.0-or-later
* The Original Code is:
* GTS - Library for the manipulation of triangulated surfaces
* Copyright 1999 Stephane Popinet
* and:
* OGF/Graphite: Geometry and Graphics Programming Library + Utilities
* Copyright 2000-2003 Bruno Levy <levy@loria.fr> */
#pragma once
/** \file
* \ingroup freestyle
* \brief GTS - Library for the manipulation of triangulated surfaces
* \brief OGF/Graphite: Geometry and Graphics Programming Library + Utilities
*/
#include "../geometry/Geom.h"
#include "../system/FreestyleConfig.h"
#include "../system/Precision.h"
#ifdef WITH_CXX_GUARDEDALLOC
# include "MEM_guardedalloc.h"
#endif
namespace Freestyle {
using namespace Geometry;
class WVertex;
class CurvatureInfo {
public:
CurvatureInfo()
{
K1 = 0.0;
K2 = 0.0;
e1 = Vec3r(0.0, 0.0, 0.0);
e2 = Vec3r(0.0, 0.0, 0.0);
Kr = 0.0;
dKr = 0.0;
er = Vec3r(0.0, 0.0, 0.0);
}
CurvatureInfo(const CurvatureInfo &iBrother)
{
K1 = iBrother.K1;
K2 = iBrother.K2;
e1 = iBrother.e1;
e2 = iBrother.e2;
Kr = iBrother.Kr;
dKr = iBrother.dKr;
er = iBrother.er;
}
CurvatureInfo(const CurvatureInfo &ca, const CurvatureInfo &cb, real t)
{
K1 = ca.K1 + t * (cb.K1 - ca.K1);
K2 = ca.K2 + t * (cb.K2 - ca.K2);
e1 = ca.e1 + t * (cb.e1 - ca.e1);
e2 = ca.e2 + t * (cb.e2 - ca.e2);
Kr = ca.Kr + t * (cb.Kr - ca.Kr);
dKr = ca.dKr + t * (cb.dKr - ca.dKr);
er = ca.er + t * (cb.er - ca.er);
}
real K1; // maximum curvature
real K2; // minimum curvature
Vec3r e1; // maximum curvature direction
Vec3r e2; // minimum curvature direction
real Kr; // radial curvature
real dKr; // radial curvature
Vec3r er; // radial curvature direction
#ifdef WITH_CXX_GUARDEDALLOC
MEM_CXX_CLASS_ALLOC_FUNCS("Freestyle:CurvatureInfo")
#endif
};
class Face_Curvature_Info {
public:
Face_Curvature_Info()
{
}
~Face_Curvature_Info()
{
for (vector<CurvatureInfo *>::iterator ci = vec_curvature_info.begin(),
ciend = vec_curvature_info.end();
ci != ciend;
++ci) {
delete (*ci);
}
vec_curvature_info.clear();
}
vector<CurvatureInfo *> vec_curvature_info;
#ifdef WITH_CXX_GUARDEDALLOC
MEM_CXX_CLASS_ALLOC_FUNCS("Freestyle:Face_Curvature_Info")
#endif
};
/**
* \param v: a #WVertex.
* \param Kh: the Mean Curvature Normal at \a v.
*
* Computes the Discrete Mean Curvature Normal approximation at \a v.
* The mean curvature at \a v is half the magnitude of the vector \a Kh.
*
* \note the normal computed is not unit length, and may point either into or out of the surface,
* depending on the curvature at \a v. It is the responsibility of the caller of the function to
* use the mean curvature normal appropriately.
*
* This approximation is from the paper:
* Discrete Differential-Geometry Operators for Triangulated 2-Manifolds
* Mark Meyer, Mathieu Desbrun, Peter Schroder, Alan H. Barr
* VisMath '02, Berlin (Germany)
* http://www-grail.usc.edu/pubs.html
*
* Returns: %true if the operator could be evaluated, %false if the evaluation failed for some
* reason (`v` is boundary or is the endpoint of a non-manifold edge.)
*/
bool gts_vertex_mean_curvature_normal(WVertex *v, Vec3r &Kh);
/**
* \param v: a #WVertex.
* \param Kg: the Discrete Gaussian Curvature approximation at \a v.
*
* Computes the Discrete Gaussian Curvature approximation at \a v.
*
* This approximation is from the paper:
* Discrete Differential-Geometry Operators for Triangulated 2-Manifolds
* Mark Meyer, Mathieu Desbrun, Peter Schroder, Alan H. Barr
* VisMath '02, Berlin (Germany)
* http://www-grail.usc.edu/pubs.html
*
* Returns: %true if the operator could be evaluated, %false if the evaluation failed for some
* reason (`v` is boundary or is the endpoint of a non-manifold edge.)
*/
bool gts_vertex_gaussian_curvature(WVertex *v, real *Kg);
/**
* \param Kh: mean curvature.
* \param Kg: Gaussian curvature.
* \param K1: first principal curvature.
* \param K2: second principal curvature.
*
* Computes the principal curvatures at a point given the mean and Gaussian curvatures at that
* point.
*
* The mean curvature can be computed as one-half the magnitude of the vector computed by
* #gts_vertex_mean_curvature_normal().
*
* The Gaussian curvature can be computed with gts_vertex_gaussian_curvature().
*/
void gts_vertex_principal_curvatures(real Kh, real Kg, real *K1, real *K2);
/**
* \param v: a #WVertex.
* \param Kh: mean curvature normal (a #Vec3r).
* \param Kg: Gaussian curvature (a real).
* \param e1: first principal curvature direction (direction of largest curvature).
* \param e2: second principal curvature direction.
*
* Computes the principal curvature directions at a point given \a Kh and \a Kg,
* the mean curvature normal and Gaussian curvatures at that point, computed with
* #gts_vertex_mean_curvature_normal() and #gts_vertex_gaussian_curvature(), respectively.
*
* Note that this computation is very approximate and tends to be unstable. Smoothing of the
* surface or the principal directions may be necessary to achieve reasonable results.
*/
void gts_vertex_principal_directions(WVertex *v, Vec3r Kh, real Kg, Vec3r &e1, Vec3r &e2);
namespace OGF {
class NormalCycle;
void compute_curvature_tensor(WVertex *start, double radius, NormalCycle &nc);
void compute_curvature_tensor_one_ring(WVertex *start, NormalCycle &nc);
} // namespace OGF
} /* namespace Freestyle */
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