SDL
2.0
SDL_test_random.c
Go to the documentation of this file.
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/*
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Simple DirectMedia Layer
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Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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/*
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A portable "32-bit Multiply with carry" random number generator.
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Used by the fuzzer component.
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Original source code contributed by A. Schiffler for GSOC project.
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*/
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#include "SDL_config.h"
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#include <stdlib.h>
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#include <stdio.h>
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#include <time.h>
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#include "
SDL_test.h
"
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/* Initialize random number generator with two integer variables */
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void
SDLTest_RandomInit
(
SDLTest_RandomContext
*
rndContext
,
unsigned
int
xi,
unsigned
int
ci)
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{
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if
(
rndContext
==
NULL
)
return
;
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/*
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* Choose a value for 'a' from this list
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* 1791398085 1929682203 1683268614 1965537969 1675393560
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* 1967773755 1517746329 1447497129 1655692410 1606218150
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* 2051013963 1075433238 1557985959 1781943330 1893513180
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* 1631296680 2131995753 2083801278 1873196400 1554115554
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*/
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rndContext
->
a
= 1655692410;
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rndContext
->
x
= 30903;
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rndContext
->
c
= 0;
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if
(xi != 0) {
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rndContext
->
x
= xi;
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}
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rndContext
->
c
= ci;
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rndContext
->
ah
=
rndContext
->
a
>> 16;
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rndContext
->
al
=
rndContext
->
a
& 65535;
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}
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/* Initialize random number generator from system time */
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void
SDLTest_RandomInitTime
(
SDLTest_RandomContext
*
rndContext
)
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{
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int
a
,
b
;
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if
(
rndContext
==
NULL
)
return
;
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srand((
unsigned
int
)
time
(
NULL
));
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a
=rand();
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srand((
unsigned
int
)clock());
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b
=rand();
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SDLTest_RandomInit
(
rndContext
,
a
,
b
);
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}
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/* Returns random numbers */
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unsigned
int
SDLTest_Random
(
SDLTest_RandomContext
*
rndContext
)
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{
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unsigned
int
xh, xl;
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if
(
rndContext
==
NULL
)
return
-1;
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xh =
rndContext
->
x
>> 16, xl =
rndContext
->
x
& 65535;
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rndContext
->
x
=
rndContext
->
x
*
rndContext
->
a
+
rndContext
->
c
;
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rndContext
->
c
=
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xh *
rndContext
->
ah
+ ((xh *
rndContext
->
al
) >> 16) +
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((xl *
rndContext
->
ah
) >> 16);
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if
(xl *
rndContext
->
al
>= (~
rndContext
->
c
+ 1))
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rndContext
->
c
++;
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return (
rndContext
->
x
);
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}
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/* vi: set ts=4 sw=4 expandtab: */
SDLTest_RandomContext::al
unsigned int al
Definition:
SDL_test_random.h:64
time
EGLSurface EGLnsecsANDROID time
Definition:
eglext.h:518
SDL_test.h
NULL
#define NULL
Definition:
begin_code.h:167
b
GLboolean GLboolean GLboolean b
Definition:
SDL_opengl_glext.h:1112
rndContext
static SDLTest_RandomContext rndContext
Definition:
SDL_test_fuzzer.c:56
SDLTest_RandomContext
Definition:
SDL_test_random.h:59
a
GLboolean GLboolean GLboolean GLboolean a
Definition:
SDL_opengl_glext.h:1112
SDLTest_RandomInitTime
void SDLTest_RandomInitTime(SDLTest_RandomContext *rndContext)
Initialize random number generator based on current system time.
Definition:
SDL_test_random.c:65
SDLTest_Random
unsigned int SDLTest_Random(SDLTest_RandomContext *rndContext)
Initialize random number generator based on current system time.
Definition:
SDL_test_random.c:80
SDLTest_RandomContext::x
unsigned int x
Definition:
SDL_test_random.h:61
SDLTest_RandomInit
void SDLTest_RandomInit(SDLTest_RandomContext *rndContext, unsigned int xi, unsigned int ci)
Initialize random number generator with two integers.
Definition:
SDL_test_random.c:41
SDLTest_RandomContext::c
unsigned int c
Definition:
SDL_test_random.h:62
SDLTest_RandomContext::ah
unsigned int ah
Definition:
SDL_test_random.h:63
SDLTest_RandomContext::a
unsigned int a
Definition:
SDL_test_random.h:60
src
test
SDL_test_random.c
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