mirror of
https://github.com/Relintai/sdl2_frt.git
synced 2024-12-29 20:27:12 +01:00
97 lines
2.7 KiB
C
97 lines
2.7 KiB
C
/*
|
|
Simple DirectMedia Layer
|
|
Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
|
|
|
|
This software is provided 'as-is', without any express or implied
|
|
warranty. In no event will the authors be held liable for any damages
|
|
arising from the use of this software.
|
|
|
|
Permission is granted to anyone to use this software for any purpose,
|
|
including commercial applications, and to alter it and redistribute it
|
|
freely, subject to the following restrictions:
|
|
|
|
1. The origin of this software must not be misrepresented; you must not
|
|
claim that you wrote the original software. If you use this software
|
|
in a product, an acknowledgment in the product documentation would be
|
|
appreciated but is not required.
|
|
2. Altered source versions must be plainly marked as such, and must not be
|
|
misrepresented as being the original software.
|
|
3. This notice may not be removed or altered from any source distribution.
|
|
*/
|
|
|
|
/*
|
|
|
|
A portable "32-bit Multiply with carry" random number generator.
|
|
|
|
Used by the fuzzer component.
|
|
Original source code contributed by A. Schiffler for GSOC project.
|
|
|
|
*/
|
|
|
|
#include "SDL_config.h"
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <time.h>
|
|
|
|
#include "SDL_test.h"
|
|
|
|
/* Initialize random number generator with two integer variables */
|
|
|
|
void SDLTest_RandomInit(SDLTest_RandomContext * rndContext, unsigned int xi, unsigned int ci)
|
|
{
|
|
if (rndContext==NULL) return;
|
|
|
|
/*
|
|
* Choose a value for 'a' from this list
|
|
* 1791398085 1929682203 1683268614 1965537969 1675393560
|
|
* 1967773755 1517746329 1447497129 1655692410 1606218150
|
|
* 2051013963 1075433238 1557985959 1781943330 1893513180
|
|
* 1631296680 2131995753 2083801278 1873196400 1554115554
|
|
*/
|
|
rndContext->a = 1655692410;
|
|
rndContext->x = 30903;
|
|
rndContext->c = 0;
|
|
if (xi != 0) {
|
|
rndContext->x = xi;
|
|
}
|
|
rndContext->c = ci;
|
|
rndContext->ah = rndContext->a >> 16;
|
|
rndContext->al = rndContext->a & 65535;
|
|
}
|
|
|
|
/* Initialize random number generator from system time */
|
|
|
|
void SDLTest_RandomInitTime(SDLTest_RandomContext * rndContext)
|
|
{
|
|
int a, b;
|
|
|
|
if (rndContext==NULL) return;
|
|
|
|
srand((unsigned int)time(NULL));
|
|
a=rand();
|
|
srand((unsigned int)clock());
|
|
b=rand();
|
|
SDLTest_RandomInit(rndContext, a, b);
|
|
}
|
|
|
|
/* Returns random numbers */
|
|
|
|
unsigned int SDLTest_Random(SDLTest_RandomContext * rndContext)
|
|
{
|
|
unsigned int xh, xl;
|
|
|
|
if (rndContext==NULL) return -1;
|
|
|
|
xh = rndContext->x >> 16, xl = rndContext->x & 65535;
|
|
rndContext->x = rndContext->x * rndContext->a + rndContext->c;
|
|
rndContext->c =
|
|
xh * rndContext->ah + ((xh * rndContext->al) >> 16) +
|
|
((xl * rndContext->ah) >> 16);
|
|
if (xl * rndContext->al >= (~rndContext->c + 1))
|
|
rndContext->c++;
|
|
return (rndContext->x);
|
|
}
|
|
|
|
/* vi: set ts=4 sw=4 expandtab: */
|