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78 lines
2.3 KiB
78 lines
2.3 KiB
/* Copyright 2014-2017 Alex 'AdUser' Z (ad_user@runbox.com) |
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* |
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* This file is part of libsimdb |
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* |
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* This program 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 2 of the License, or |
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* (at your option) any later version. |
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*/ |
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/** |
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* @file |
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* @brief Functions for work with image bitmaps |
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*/ |
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#include "common.h" |
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#include "bitmap.h" |
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/** bictionary for speedup bitmap comparing */ |
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static unsigned char dict[256] = { |
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/* 0x00 _0 _1 _2 _3 _4 _5 _6 _7 _8 _9 _A _B _C _D _E _F */ |
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/* ---------------------------------------------------- */ |
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/* 0_ */ 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, |
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/* 1_ */ 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
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/* 2_ */ 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
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/* 3_ */ 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
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/* 4_ */ 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
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/* 5_ */ 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
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/* 6_ */ 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
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/* 7_ */ 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
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/* 8_ */ 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, |
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/* 9_ */ 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
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/* A_ */ 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
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/* B_ */ 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
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/* C_ */ 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, |
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/* D_ */ 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
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/* E_ */ 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, |
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/* F_ */ 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8, |
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}; |
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int |
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simdb_bitmap_compare(const unsigned char *a, const unsigned char *b) { |
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unsigned char diff = 0; |
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size_t i = 0; |
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size_t cnt = 0; |
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for (i = 0; i < SIMDB_BITMAP_SIZE; i++, a++, b++) { |
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diff = *a ^ *b; |
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cnt += dict[diff]; |
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} |
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return cnt; |
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} |
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size_t |
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simdb_bitmap_unpack(const unsigned char *map, char **buf) { |
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size_t buf_size = SIMDB_BITMAP_BITS; |
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uint16_t *p, row, mask; |
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char *q = NULL; |
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assert(map != NULL); |
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assert(buf != NULL); |
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if ((*buf = calloc(buf_size, sizeof(char))) == NULL) |
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return 0; |
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p = (uint16_t *) map; |
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q = *buf; |
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for (size_t i = 0; i < SIMDB_BITMAP_SIDE; i++, p++) { |
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row = *p; mask = 0x1; |
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for (size_t j = 0; j < SIMDB_BITMAP_SIDE; j++, q++) { |
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*q = (row & mask) ? 0x1 : 0x0; |
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mask <<= 1; |
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} |
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} |
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return buf_size; |
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}
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