| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2023 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)SDL_GetPerformanceCounter()); |
| 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: */ |