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| Rev | Author | Line No. | Line | 
|---|---|---|---|
| 11 | pmbaty | 1 | /* | 
| 2 |   Simple DirectMedia Layer | ||
| 3 |   Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org> | ||
| 4 | |||
| 5 |   This software is provided 'as-is', without any express or implied | ||
| 6 |   warranty.  In no event will the authors be held liable for any damages | ||
| 7 |   arising from the use of this software. | ||
| 8 | |||
| 9 |   Permission is granted to anyone to use this software for any purpose, | ||
| 10 |   including commercial applications, and to alter it and redistribute it | ||
| 11 |   freely, subject to the following restrictions: | ||
| 12 | |||
| 13 |   1. The origin of this software must not be misrepresented; you must not | ||
| 14 |      claim that you wrote the original software. If you use this software | ||
| 15 |      in a product, an acknowledgment in the product documentation would be | ||
| 16 |      appreciated but is not required. | ||
| 17 |   2. Altered source versions must be plainly marked as such, and must not be | ||
| 18 |      misrepresented as being the original software. | ||
| 19 |   3. This notice may not be removed or altered from any source distribution. | ||
| 20 | */ | ||
| 21 | |||
| 22 | /** | ||
| 23 |  *  \file SDL_test_random.h | ||
| 24 |  * | ||
| 25 |  *  Include file for SDL test framework. | ||
| 26 |  * | ||
| 27 |  *  This code is a part of the SDL2_test library, not the main SDL library. | ||
| 28 |  */ | ||
| 29 | |||
| 30 | /* | ||
| 31 | |||
| 32 |  A "32-bit Multiply with carry random number generator. Very fast. | ||
| 33 |  Includes a list of recommended multipliers. | ||
| 34 | |||
| 35 |  multiply-with-carry generator: x(n) = a*x(n-1) + carry mod 2^32. | ||
| 36 |  period: (a*2^31)-1 | ||
| 37 | |||
| 38 | */ | ||
| 39 | |||
| 40 | #ifndef SDL_test_random_h_ | ||
| 41 | #define SDL_test_random_h_ | ||
| 42 | |||
| 43 | #include "begin_code.h" | ||
| 44 | /* Set up for C function definitions, even when using C++ */ | ||
| 45 | #ifdef __cplusplus | ||
| 46 | extern "C" { | ||
| 47 | #endif | ||
| 48 | |||
| 49 | /* --- Definitions */ | ||
| 50 | |||
| 51 | /* | ||
| 52 |  * Macros that return a random number in a specific format. | ||
| 53 |  */ | ||
| 54 | #define SDLTest_RandomInt(c)        ((int)SDLTest_Random(c)) | ||
| 55 | |||
| 56 | /* | ||
| 57 |  * Context structure for the random number generator state. | ||
| 58 |  */ | ||
| 59 | typedef struct { | ||
| 60 | unsigned int a; | ||
| 61 | unsigned int x; | ||
| 62 | unsigned int c; | ||
| 63 | unsigned int ah; | ||
| 64 | unsigned int al; | ||
| 65 | } SDLTest_RandomContext; | ||
| 66 | |||
| 67 | |||
| 68 | /* --- Function prototypes */ | ||
| 69 | |||
| 70 | /** | ||
| 71 |  *  \brief Initialize random number generator with two integers. | ||
| 72 |  * | ||
| 73 |  *  Note: The random sequence of numbers returned by ...Random() is the | ||
| 74 |  *  same for the same two integers and has a period of 2^31. | ||
| 75 |  * | ||
| 76 |  *  \param rndContext     pointer to context structure | ||
| 77 |  *  \param xi         integer that defines the random sequence | ||
| 78 |  *  \param ci         integer that defines the random sequence | ||
| 79 |  * | ||
| 80 |  */ | ||
| 81 | void SDLTest_RandomInit(SDLTest_RandomContext * rndContext, unsigned int xi, | ||
| 82 | unsigned int ci); | ||
| 83 | |||
| 84 | /** | ||
| 85 |  *  \brief Initialize random number generator based on current system time. | ||
| 86 |  * | ||
| 87 |  *  \param rndContext     pointer to context structure | ||
| 88 |  * | ||
| 89 |  */ | ||
| 90 | void SDLTest_RandomInitTime(SDLTest_RandomContext *rndContext); | ||
| 91 | |||
| 92 | |||
| 93 | /** | ||
| 94 |  *  \brief Initialize random number generator based on current system time. | ||
| 95 |  * | ||
| 96 |  *  Note: ...RandomInit() or ...RandomInitTime() must have been called | ||
| 97 |  *  before using this function. | ||
| 98 |  * | ||
| 99 |  *  \param rndContext     pointer to context structure | ||
| 100 |  * | ||
| 101 |  *  \returns a random number (32bit unsigned integer) | ||
| 102 |  * | ||
| 103 |  */ | ||
| 104 | unsigned int SDLTest_Random(SDLTest_RandomContext *rndContext); | ||
| 105 | |||
| 106 | |||
| 107 | /* Ends C function definitions when using C++ */ | ||
| 108 | #ifdef __cplusplus | ||
| 109 | } | ||
| 110 | #endif | ||
| 111 | #include "close_code.h" | ||
| 112 | |||
| 113 | #endif /* SDL_test_random_h_ */ | ||
| 114 | |||
| 115 | /* vi: set ts=4 sw=4 expandtab: */ |