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allow STBIW_CRC32 override default crc32

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This commit is contained in:
jarnoh 2018-07-26 17:10:40 +03:00
parent e6afb9cbae
commit 7a02732eb3
1 changed files with 4 additions and 0 deletions
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4
stb_image_write.h
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@ -923,6 +923,9 @@ unsigned char * stbi_zlib_compress(unsigned char *data, int data_len, int *out_l
static unsigned int stbiw__crc32(unsigned char *buffer, int len) static unsigned int stbiw__crc32(unsigned char *buffer, int len)
{ {
#ifdef STBIW_CRC32
return STBIW_CRC32(buffer, len);
#else
static unsigned int crc_table[256] = static unsigned int crc_table[256] =
{ {
0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3, 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
@ -964,6 +967,7 @@ static unsigned int stbiw__crc32(unsigned char *buffer, int len)
for (i=0; i < len; ++i) for (i=0; i < len; ++i)
crc = (crc >> 8) ^ crc_table[buffer[i] ^ (crc & 0xff)]; crc = (crc >> 8) ^ crc_table[buffer[i] ^ (crc & 0xff)];
return ~crc; return ~crc;
#endif
} }
#define stbiw__wpng4(o,a,b,c,d) ((o)[0]=STBIW_UCHAR(a),(o)[1]=STBIW_UCHAR(b),(o)[2]=STBIW_UCHAR(c),(o)[3]=STBIW_UCHAR(d),(o)+=4) #define stbiw__wpng4(o,a,b,c,d) ((o)[0]=STBIW_UCHAR(a),(o)[1]=STBIW_UCHAR(b),(o)[2]=STBIW_UCHAR(c),(o)[3]=STBIW_UCHAR(d),(o)+=4)