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/* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
/** \file
* \ingroup bli
*
* General looping helpers, use `BLI_FOREACH` prefix.
*/
/**
* Even value distribution.
*
* \a src must be larger than \a dst,
* \a dst defines the number of iterations, their values are evenly spaced.
*
* The following pairs represent (src, dst) arguments and the values they loop over.
* <pre>
* (19, 4) -> [2, 7, 11. 16]
* (100, 5) -> [9, 29, 49, 69, 89]
* (100, 3) -> [16, 49, 83]
* (100, 100) -> [0..99]
* </pre>
* \note this is mainly useful for numbers that might not divide evenly into eachother.
*/
#define BLI_FOREACH_SPARSE_RANGE(src, dst, i) \
for (int _src = (src), _src2 = _src * 2, _dst2 = (dst)*2, _error = _dst2 - _src, i = 0, _delta; \
((void)(_delta = divide_floor_i(_error, _dst2)), (void)(i -= _delta), (i < _src)); \
_error -= (_delta * _dst2) + _src2)
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