1 #ifndef _DERANDOM_H 2 #define _DERANDOM_H 3 /*------------------------------------------------------------------------- 4 * drawElements Base Portability Library 5 * ------------------------------------- 6 * 7 * Copyright 2014 The Android Open Source Project 8 * 9 * Licensed under the Apache License, Version 2.0 (the "License"); 10 * you may not use this file except in compliance with the License. 11 * You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, 17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 * 21 *//*! 22 * \file 23 * \brief Random number generation. 24 *//*--------------------------------------------------------------------*/ 25 26 #include "deDefs.h" 27 28 DE_BEGIN_EXTERN_C 29 30 /*--------------------------------------------------------------------*//*! 31 * \brief Random number generator. 32 * 33 * Uses the Xorshift algorithm for producing pseudo-random numbers. The 34 * values are generated based on an initial seed and the same seed always 35 * produces the same sequence of numbers. 36 * 37 * See: http://en.wikipedia.org/wiki/Xorshift 38 *//*--------------------------------------------------------------------*/ 39 typedef struct deRandom_s 40 { 41 uint32_t x; /*!< Current random state. */ 42 uint32_t y; 43 uint32_t z; 44 uint32_t w; 45 } deRandom; 46 47 void deRandom_init(deRandom *rnd, uint32_t seed); 48 uint32_t deRandom_getUint32(deRandom *rnd); 49 uint64_t deRandom_getUint64(deRandom *rnd); 50 float deRandom_getFloat(deRandom *rnd); 51 double deRandom_getDouble(deRandom *rnd); 52 bool deRandom_getBool(deRandom *rnd); 53 54 DE_END_EXTERN_C 55 56 #endif /* _DERANDOM_H */ 57