diff options
author | Brecht Van Lommel <brecht@blender.org> | 2021-10-24 15:19:19 +0300 |
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committer | Brecht Van Lommel <brecht@blender.org> | 2021-10-26 16:37:04 +0300 |
commit | fd25e883e2807a151f673b87c152a59701a0df80 (patch) | |
tree | 9441933f32ba2672ca71c58842342a9c525e123e /intern/cycles/util/murmurhash.cpp | |
parent | d7d40745fa09061a3117bd3669c5a46bbf611eae (diff) |
Cycles: remove prefix from source code file names
Remove prefix of filenames that is the same as the folder name. This used
to help when #includes were using individual files, but now they are always
relative to the cycles root directory and so the prefixes are redundant.
For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
Diffstat (limited to 'intern/cycles/util/murmurhash.cpp')
-rw-r--r-- | intern/cycles/util/murmurhash.cpp | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/intern/cycles/util/murmurhash.cpp b/intern/cycles/util/murmurhash.cpp new file mode 100644 index 00000000000..9ba0a282cc2 --- /dev/null +++ b/intern/cycles/util/murmurhash.cpp @@ -0,0 +1,126 @@ +/* + * Copyright 2018 Blender Foundation + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* This is taken from alShaders/Cryptomatte/MurmurHash3.h: + * + * MurmurHash3 was written by Austin Appleby, and is placed in the public + * domain. The author hereby disclaims copyright to this source code. + */ + +#include <stdlib.h> +#include <string.h> + +#include "util/algorithm.h" +#include "util/murmurhash.h" + +#if defined(_MSC_VER) +# define ROTL32(x, y) _rotl(x, y) +# define ROTL64(x, y) _rotl64(x, y) +# define BIG_CONSTANT(x) (x) +#else +ccl_device_inline uint32_t rotl32(uint32_t x, int8_t r) +{ + return (x << r) | (x >> (32 - r)); +} +# define ROTL32(x, y) rotl32(x, y) +# define BIG_CONSTANT(x) (x##LLU) +#endif + +CCL_NAMESPACE_BEGIN + +/* Block read - if your platform needs to do endian-swapping or can only + * handle aligned reads, do the conversion here. */ +ccl_device_inline uint32_t mm_hash_getblock32(const uint32_t *p, int i) +{ + return p[i]; +} + +/* Finalization mix - force all bits of a hash block to avalanche */ +ccl_device_inline uint32_t mm_hash_fmix32(uint32_t h) +{ + h ^= h >> 16; + h *= 0x85ebca6b; + h ^= h >> 13; + h *= 0xc2b2ae35; + h ^= h >> 16; + return h; +} + +uint32_t util_murmur_hash3(const void *key, int len, uint32_t seed) +{ + const uint8_t *data = (const uint8_t *)key; + const int nblocks = len / 4; + + uint32_t h1 = seed; + + const uint32_t c1 = 0xcc9e2d51; + const uint32_t c2 = 0x1b873593; + + const uint32_t *blocks = (const uint32_t *)(data + nblocks * 4); + + for (int i = -nblocks; i; i++) { + uint32_t k1 = mm_hash_getblock32(blocks, i); + + k1 *= c1; + k1 = ROTL32(k1, 15); + k1 *= c2; + + h1 ^= k1; + h1 = ROTL32(h1, 13); + h1 = h1 * 5 + 0xe6546b64; + } + + const uint8_t *tail = (const uint8_t *)(data + nblocks * 4); + + uint32_t k1 = 0; + + switch (len & 3) { + case 3: + k1 ^= tail[2] << 16; + ATTR_FALLTHROUGH; + case 2: + k1 ^= tail[1] << 8; + ATTR_FALLTHROUGH; + case 1: + k1 ^= tail[0]; + k1 *= c1; + k1 = ROTL32(k1, 15); + k1 *= c2; + h1 ^= k1; + } + + h1 ^= len; + h1 = mm_hash_fmix32(h1); + return h1; +} + +/* This is taken from the cryptomatte specification 1.0 */ +float util_hash_to_float(uint32_t hash) +{ + uint32_t mantissa = hash & ((1 << 23) - 1); + uint32_t exponent = (hash >> 23) & ((1 << 8) - 1); + exponent = max(exponent, (uint32_t)1); + exponent = min(exponent, (uint32_t)254); + exponent = exponent << 23; + uint32_t sign = (hash >> 31); + sign = sign << 31; + uint32_t float_bits = sign | exponent | mantissa; + float f; + memcpy(&f, &float_bits, sizeof(uint32_t)); + return f; +} + +CCL_NAMESPACE_END |