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