113 lines
3.1 KiB
C
113 lines
3.1 KiB
C
|
/*
|
||
|
|
Simple DirectMedia Layer
|
||
|
|
Copyright (C) 1997-2024 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* \file SDL_test_random.h
|
||
|
|
*
|
||
|
|
* Random number generator related function of SDL test framework.
|
||
|
|
*
|
||
|
|
* This code is a part of the SDL test library, not the main SDL library.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
|
||
|
|
A "32-bit Multiply with carry random number generator. Very fast.
|
||
|
|
Includes a list of recommended multipliers.
|
||
|
|
|
||
|
|
multiply-with-carry generator: x(n) = a*x(n-1) + carry mod 2^32.
|
||
|
|
period: (a*2^31)-1
|
||
|
|
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef SDL_test_random_h_
|
||
|
|
#define SDL_test_random_h_
|
||
|
|
|
||
|
|
#include <SDL3/SDL_begin_code.h>
|
||
|
|
/* Set up for C function definitions, even when using C++ */
|
||
|
|
#ifdef __cplusplus
|
||
|
|
extern "C" {
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* --- Definitions */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Macros that return a random number in a specific format.
|
||
|
|
*/
|
||
|
|
#define SDLTest_RandomInt(c) ((int)SDLTest_Random(c))
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Context structure for the random number generator state.
|
||
|
|
*/
|
||
|
|
typedef struct SDLTest_RandomContext {
|
||
|
|
unsigned int a;
|
||
|
|
unsigned int x;
|
||
|
|
unsigned int c;
|
||
|
|
unsigned int ah;
|
||
|
|
unsigned int al;
|
||
|
|
} SDLTest_RandomContext;
|
||
|
|
|
||
|
|
|
||
|
|
/* --- Function prototypes */
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Initialize random number generator with two integers.
|
||
|
|
*
|
||
|
|
* Note: The random sequence of numbers returned by ...Random() is the
|
||
|
|
* same for the same two integers and has a period of 2^31.
|
||
|
|
*
|
||
|
|
* \param rndContext pointer to context structure
|
||
|
|
* \param xi integer that defines the random sequence
|
||
|
|
* \param ci integer that defines the random sequence
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
void SDLTest_RandomInit(SDLTest_RandomContext *rndContext, unsigned int xi, unsigned int ci);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Initialize random number generator based on current system time.
|
||
|
|
*
|
||
|
|
* \param rndContext pointer to context structure
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
void SDLTest_RandomInitTime(SDLTest_RandomContext *rndContext);
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Initialize random number generator based on current system time.
|
||
|
|
*
|
||
|
|
* Note: ...RandomInit() or ...RandomInitTime() must have been called
|
||
|
|
* before using this function.
|
||
|
|
*
|
||
|
|
* \param rndContext pointer to context structure
|
||
|
|
*
|
||
|
|
* \returns a random number (32bit unsigned integer)
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
unsigned int SDLTest_Random(SDLTest_RandomContext *rndContext);
|
||
|
|
|
||
|
|
|
||
|
|
/* Ends C function definitions when using C++ */
|
||
|
|
#ifdef __cplusplus
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
#include <SDL3/SDL_close_code.h>
|
||
|
|
|
||
|
|
#endif /* SDL_test_random_h_ */
|