include/SDL_test_random.h
author Ryan C. Gordon <icculus@icculus.org>
Fri, 20 Mar 2015 21:57:15 -0400
changeset 9414 669bf9fb901e
parent 8149 681eb46b8ac4
child 9619 b94b6d0bff0f
permissions -rw-r--r--
Several corrections to the CMake project files (thanks, Ozkan!).

Fixes Bugzilla #2732.
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/*
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  Simple DirectMedia Layer
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  Copyright (C) 1997-2014 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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 *  \file SDL_test_random.h
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 *
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 *  Include file for SDL test framework.
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 *
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 *  This code is a part of the SDL2_test library, not the main SDL library.
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 */
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/*
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 A "32-bit Multiply with carry random number generator. Very fast.
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 Includes a list of recommended multipliers.
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 multiply-with-carry generator: x(n) = a*x(n-1) + carry mod 2^32.
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 period: (a*2^31)-1
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*/
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#ifndef _SDL_test_random_h
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#define _SDL_test_random_h
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#include "begin_code.h"
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/* Set up for C function definitions, even when using C++ */
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* --- Definitions */
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/*
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 * Macros that return a random number in a specific format.
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 */
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#define SDLTest_RandomInt(c)        ((int)SDLTest_Random(c))
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/*
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 * Context structure for the random number generator state.
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 */
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  typedef struct {
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    unsigned int a;
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    unsigned int x;
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    unsigned int c;
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    unsigned int ah;
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    unsigned int al;
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  } SDLTest_RandomContext;
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/* --- Function prototypes */
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/**
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 *  \brief Initialize random number generator with two integers.
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 *
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 *  Note: The random sequence of numbers returned by ...Random() is the
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 *  same for the same two integers and has a period of 2^31.
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 *
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 *  \param rndContext     pointer to context structure
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 *  \param xi         integer that defines the random sequence
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 *  \param ci         integer that defines the random sequence
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 *
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 */
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 void SDLTest_RandomInit(SDLTest_RandomContext * rndContext, unsigned int xi,
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                  unsigned int ci);
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/**
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 *  \brief Initialize random number generator based on current system time.
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 *
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 *  \param rndContext     pointer to context structure
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 *
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 */
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 void SDLTest_RandomInitTime(SDLTest_RandomContext *rndContext);
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/**
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 *  \brief Initialize random number generator based on current system time.
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 *
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 *  Note: ...RandomInit() or ...RandomInitTime() must have been called
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 *  before using this function.
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 *
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 *  \param rndContext     pointer to context structure
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 *
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 *  \returns A random number (32bit unsigned integer)
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 *
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 */
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 unsigned int SDLTest_Random(SDLTest_RandomContext *rndContext);
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/* Ends C function definitions when using C++ */
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#ifdef __cplusplus
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}
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#endif
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#include "close_code.h"
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#endif /* _SDL_test_random_h */
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