diff options
Diffstat (limited to 'src/port/rand.c')
| -rw-r--r-- | src/port/rand.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/src/port/rand.c b/src/port/rand.c new file mode 100644 index 0000000000..faeec88b28 --- /dev/null +++ b/src/port/rand.c @@ -0,0 +1,78 @@ +/*------------------------------------------------------------------------- + * + * rand.c + * Missing rand implementations for Win32 + * + *------------------------------------------------------------------------- + */ + +/* + * Copyright (c) 1993 Martin Birgmeier + * All rights reserved. + * + * You may redistribute unmodified or modified versions of this source + * code provided that the above copyright notice and this and the + * following conditions are retained. + * + * This software is provided ``as is'', and comes with no warranties + * of any kind. I shall in no event be liable for anything that happens + * to anyone/anything when using this software. + */ +#define RAND48_SEED_0 (0x330e) +#define RAND48_SEED_1 (0xabcd) +#define RAND48_SEED_2 (0x1234) +#define RAND48_MULT_0 (0xe66d) +#define RAND48_MULT_1 (0xdeec) +#define RAND48_MULT_2 (0x0005) +#define RAND48_ADD (0x000b) + +unsigned short _rand48_seed[3] = { + RAND48_SEED_0, + RAND48_SEED_1, + RAND48_SEED_2 +}; +unsigned short _rand48_mult[3] = { + RAND48_MULT_0, + RAND48_MULT_1, + RAND48_MULT_2 +}; +unsigned short _rand48_add = RAND48_ADD; + +void +_dorand48(unsigned short xseed[3]) +{ + unsigned long accu; + unsigned short temp[2]; + + accu = (unsigned long) _rand48_mult[0] * (unsigned long) xseed[0] + + (unsigned long) _rand48_add; + temp[0] = (unsigned short) accu; /* lower 16 bits */ + accu >>= sizeof(unsigned short) * 8; + accu += (unsigned long) _rand48_mult[0] * (unsigned long) xseed[1] + + (unsigned long) _rand48_mult[1] * (unsigned long) xseed[0]; + temp[1] = (unsigned short) accu; /* middle 16 bits */ + accu >>= sizeof(unsigned short) * 8; + accu += _rand48_mult[0] * xseed[2] + _rand48_mult[1] * xseed[1] + _rand48_mult[2] * xseed[0]; + xseed[0] = temp[0]; + xseed[1] = temp[1]; + xseed[2] = (unsigned short) accu; +} + +long +lrand48(void) +{ + _dorand48(_rand48_seed); + return ((long) _rand48_seed[2] << 15) + ((long) _rand48_seed[1] >1); +} + +void +srand48(long seed) +{ + _rand48_seed[0] = RAND48_SEED_0; + _rand48_seed[1] = (unsigned short) seed; + _rand48_seed[2] = (unsigned short) (seed >16); + _rand48_mult[0] = RAND48_MULT_0; + _rand48_mult[1] = RAND48_MULT_1; + _rand48_mult[2] = RAND48_MULT_2; + _rand48_add = RAND48_ADD; +} |
