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CHG: some textual change to README.txt

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ADD: a prng.c to collect some different PRNG's i've ran into
ADD: some changes the tea implementation
ADD: a enhanced version - SwapEndian64ex
This commit is contained in:
iceman1001 2015-12-21 19:48:00 +01:00
commit f4d0ffd1b9
8 changed files with 86 additions and 37 deletions
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39
common/prng.c Normal file
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//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// Burtle Prng - Modified. 42iterations instead of 20.
// ref: http://burtleburtle.net/bob/rand/smallprng.html
//-----------------------------------------------------------------------------
#include "prng.h"
#define rot(x,k) (((x)<<(k))|((x)>>(32-(k))))
uint32_t burtle_get_mod( prng_ctx *x ) {
uint32_t e = x->a - rot(x->b, 21);
x->a = x->b ^ rot(x->c, 19);
x->b = x->c + rot(x->d, 6);
x->c = x->d + e;
x->d = e + x->a;
return x->d;
}
void burtle_init_mod(prng_ctx *x, uint32_t seed ) {
x->a = 0xf1ea5eed;
x->b = x->c = x->d = seed;
for (uint8_t i=0; i < 42; ++i) {
(void)burtle_get_mod(x);
}
}
void burtle_init(prng_ctx *x, uint32_t seed ) {
uint32_t i;
x->a = 0xf1ea5eed, x->b = x->c = x->d = seed;
for (i=0; i < 20; ++i) {
(void)burtle_get_mod(x);
}
}
uint32_t GetSimplePrng( uint32_t seed ){
seed *= 0x19660D;
seed += 0x3C6EF35F;
return seed;
}