BambuStudio/libigl/igl/unzip_corners.h

55 lines
2.1 KiB
C++

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2016 Alec Jacobson <alecjacobson@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#ifndef IGL_UNZIP_CORNERS_H
#define IGL_UNZIP_CORNERS_H
#include "igl_inline.h"
#include <Eigen/Core>
#include <vector>
#include <functional>
namespace igl
{
// UNZIP_CORNERS Given a triangle mesh where corners of each triangle index
// different matrices of attributes (e.g. read from an OBJ file), unzip the
// corners into unique efficiently: attributes become properly vertex valued
// (usually creating greater than #V but less than #F*3 vertices).
//
// To pass a list of attributes this function takes an std::vector of
// std::reference_wrapper of an Eigen::... type. This allows you to use list
// initializers **without** incurring a copy, but means you'll need to
// provide the derived type of A as an explicit template parameter:
//
// unzip_corners<Eigen::MatrixXi>({F,FTC,FN},U,G,J);
//
// Inputs:
// A #A list of #F by 3 attribute indices, typically {F,FTC,FN}
// Outputs:
// U #U by #A list of indices into each attribute for each unique mesh
// vertex: U(v,a) is the attribute index of vertex v in attribute a.
// G #F by 3 list of triangle indices into U
// Example:
// [V,F,TC,FTC] = readOBJ('~/Downloads/kiwis/kiwi.obj');
// [U,G] = unzip_corners(cat(3,F,FTC));
// % display mesh
// tsurf(G,V(U(:,1),:));
// % display texture coordinates
// tsurf(G,TC(U(:,2),:));
//
template < typename DerivedA, typename DerivedU, typename DerivedG, typename DerivedJ>
IGL_INLINE void unzip_corners(
const std::vector<std::reference_wrapper<DerivedA> > & A,
Eigen::PlainObjectBase<DerivedU> & U,
Eigen::PlainObjectBase<DerivedG> & G,
Eigen::PlainObjectBase<DerivedJ> & J);
}
#ifndef IGL_STATIC_LIBRARY
# include "unzip_corners.cpp"
#endif
#endif