compactness.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
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 * Copyright(C) 2021-2025                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
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 * Mozilla Public License Version 2.0                                        *
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 ****************************************************************************/
 
#ifndef VCL_MISC_COMPACTNESS_H
#define VCL_MISC_COMPACTNESS_H
 
#include <vclib/types.h>
 
#include <vector>
 
namespace vcl {
 
template<typename T, typename... Args>
void compactVector(
    std::vector<T, Args...>& vec,
    const std::vector<uint>& newIndices)
{
    assert(vec.size() == newIndices.size());
    uint newSize = 0;
    for (uint i = 0; i < newIndices.size(); ++i) {
        if (newIndices[i] != UINT_NULL) {
            ++newSize;
            if (newIndices[i] != i) {
                // must move the element from position i to position
                // newIndices[i]
                vec[newIndices[i]] = std::move(vec[i]);
            }
        }
    }
    vec.resize(newSize);
}
 
} // namespace vcl
 
#endif // VCL_MISC_COMPACTNESS_H