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Removed SDL_rand_r()

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John Kaniarz 2024-06-19 13:21:28 -04:00 • committed by Sam Lantinga
parent 86b06f74dc
commit 16e69cb4c9
4 changed files with 15 additions and 51 deletions
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36
src/stdlib/SDL_random.c
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@ -39,26 +39,6 @@ Uint32 SDL_rand(void)
if(!SDL_rand_initialized) {
SDL_srand(0);
}
return SDL_rand_r(&SDL_rand_state);
}
Uint32 SDL_rand_n(Uint32 n)
{
// On 32-bit arch, the compiler will optimize to a single 32-bit multiply
Uint64 val = (Uint64)SDL_rand() * n;
return (Uint32)(val >> 32);
}
float SDL_rand_float(void)
{
return (SDL_rand() >> (32-24)) * 0x1p-24f;
}
Uint32 SDL_rand_r(Uint64 *state)
{
if (!state) {
return 0;
}
// The C and A parameters of this LCG have been chosen based on hundreds
// of core-hours of testing with PractRand and TestU01's Crush.
@ -75,8 +55,20 @@ Uint32 SDL_rand_r(Uint64 *state)
// Softw Pract Exper. 2022;52(2):443-458. doi: 10.1002/spe.3030
// https://arxiv.org/abs/2001.05304v2
*state = *state * 0xff1cd035ul + 0x05;
SDL_rand_state = SDL_rand_state * 0xff1cd035ul + 0x05;
// Only return top 32 bits because they have a longer period
return (Uint32)(*state >> 32);
return (Uint32)(SDL_rand_state >> 32);
}
Uint32 SDL_rand_n(Uint32 n)
{
// On 32-bit arch, the compiler will optimize to a single 32-bit multiply
Uint64 val = (Uint64)SDL_rand() * n;
return (Uint32)(val >> 32);
}
float SDL_rand_float(void)
{
return (SDL_rand() >> (32-24)) * 0x1p-24f;
}