💿🐜 Antkeeper source code
https://antkeeper.com
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85 lines
2.2 KiB
85 lines
2.2 KiB
/*
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* Copyright (C) 2020 Christopher J. Howard
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*
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* This file is part of Antkeeper source code.
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*
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* Antkeeper source code is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Antkeeper source code is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "morton.hpp"
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namespace morton {
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std::uint32_t encode_2d(std::uint32_t x, std::uint32_t y)
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{
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auto interleave = [](std::uint32_t x) -> std::uint32_t
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{
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x &= 0x0000ffff;
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x = (x ^ (x << 8)) & 0x00ff00ff;
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x = (x ^ (x << 4)) & 0x0f0f0f0f;
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x = (x ^ (x << 2)) & 0x33333333;
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x = (x ^ (x << 1)) & 0x55555555;
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return x;
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};
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return (interleave(y) << 1) + interleave(x);
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}
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std::uint32_t encode_3d(std::uint32_t x, std::uint32_t y, std::uint32_t z)
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{
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auto interleave = [](std::uint32_t x) -> std::uint32_t
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{
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x &= 0x000003ff;
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x = (x ^ (x << 16)) & 0xff0000ff;
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x = (x ^ (x << 8)) & 0x0300f00f;
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x = (x ^ (x << 4)) & 0x030c30c3;
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x = (x ^ (x << 2)) & 0x09249249;
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return x;
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};
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return interleave(x) | (interleave(y) << 1) | (interleave(z) << 2);
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}
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std::array<uint32_t, 2> decode_2d(std::uint32_t code)
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{
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auto unravel = [](std::uint32_t x) -> std::uint32_t
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{
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x &= 0x55555555;
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x = (x ^ (x >> 1)) & 0x33333333;
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x = (x ^ (x >> 2)) & 0x0f0f0f0f;
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x = (x ^ (x >> 4)) & 0x00ff00ff;
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x = (x ^ (x >> 8)) & 0x0000ffff;
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return x;
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};
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return {unravel(code >> 0), unravel(code >> 1)};
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}
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std::array<uint32_t, 3> decode_3d(std::uint32_t code)
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{
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auto unravel = [](std::uint32_t x) -> std::uint32_t
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{
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x &= 0x09249249;
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x = (x ^ (x >> 2)) & 0x030c30c3;
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x = (x ^ (x >> 4)) & 0x0300f00f;
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x = (x ^ (x >> 8)) & 0xff0000ff;
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x = (x ^ (x >> 16)) & 0x000003ff;
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return x;
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};
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return {unravel(code >> 0), unravel(code >> 1), unravel(code >> 2)};
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}
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} // namespace morton
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