diff options
author | 2016-02-27 16:28:05 +0100 | |
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committer | 2016-02-27 16:53:49 +0100 | |
commit | cf6dc7d370407914020f3e623719f09c8668c692 (patch) | |
tree | 46b3416d091b4c09b50fba7ffcbd310aed032cc8 /3rdparty/SDL2/src/test/SDL_test_random.c | |
parent | 64135e73f973d9b95beb0c60b65feb34fbfec64a (diff) |
Placed SDL2 source since we need it on some platforms (nw)
Diffstat (limited to '3rdparty/SDL2/src/test/SDL_test_random.c')
-rw-r--r-- | 3rdparty/SDL2/src/test/SDL_test_random.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/3rdparty/SDL2/src/test/SDL_test_random.c b/3rdparty/SDL2/src/test/SDL_test_random.c new file mode 100644 index 00000000000..c5baaa640f3 --- /dev/null +++ b/3rdparty/SDL2/src/test/SDL_test_random.c @@ -0,0 +1,94 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2016 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(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); +} |