added random number generation algorithms

2022-10-24 03:29:42 +06:00
parent 0e6a0f6482
commit f33804f5b8
20 changed files with 810 additions and 3 deletions
--- a/src/random/krandom.h
+++ b/src/random/krandom.h
@@ -0,0 +1,91 @@
+#pragma once
+
+#if __cplusplus
+extern "C" {
+#endif
+
+#include "../base/std.h"
+
+/*
+You can choose any algorithm that has required functions:
+
+    some_alg64_state some_alg64_init(uint64 seed);
+    uint64 some_alg64_next(some_alg64_state);
+
+    #define KRAND_ALG64 some_alg64
+    #include "kerep/random/krandom.h"
+
+The same way it works for 32-bit RNGs:
+
+    some_alg64_state some_alg32_init(uint32 seed);
+    uint32 some_alg32_next(some_alg64_state);
+
+    #define KRAND_ALG32 some_alg32
+    #include "kerep/random/krandom.h"
+*/
+
+// default rng_next function
+#ifndef KRAND_ALG32
+    #define KRAND_ALG32 xoroshiro128plus
+#endif
+#ifndef KRAND_ALG64
+    #define KRAND_ALG64 xoshiro128plus
+#endif
+
+typedef void* KRAND_ALG32_state;
+typedef void* KRAND_ALG64_state;
+#define KRAND_ALG32_next(STATE)    xoshiro128plus##_next(STATE)
+#define KRAND_ALG32_init(SEED)     xoshiro128plus##_init(SEED)
+#define KRAND_ALG32_initFromTime() xoshiro128plus##_initFromTime()
+#define KRAND_ALG64_next(STATE)    xoshiro256plus##_next(STATE)
+#define KRAND_ALG64_init(SEED)     xoshiro256plus##_init(SEED)
+#define KRAND_ALG64_initFromTime() xoshiro256plus##_initFromTime()
+
+
+#define __krand_declare_alg(ALG, VALUE_SIZE)\
+    typedef void* ALG##_state;\
+    ALG##_state ALG##_init(uint64 seed);\
+    static inline ALG##_state  ALG##_initFromTime(void) { return ALG##_init(time(NULL)); }\
+    uint##VALUE_SIZE ALG##_next(ALG##_state);
+
+// different algorithm declarations
+// for ALG32
+    // xoroshiro64
+__krand_declare_alg(xoroshiro64star,      32)
+__krand_declare_alg(xoroshiro64starstar,  32)
+    // xoshiro128
+__krand_declare_alg(xoshiro128plus,       32)
+__krand_declare_alg(xoshiro128plusplus,   32)
+__krand_declare_alg(xoshiro128starstar,   32)
+// for ALG64
+    // xoroshiro128
+__krand_declare_alg(xoroshiro128plus,     64)
+__krand_declare_alg(xoroshiro128plusplus, 64)
+__krand_declare_alg(xoroshiro128starstar, 64)
+    // xoshiro256
+__krand_declare_alg(xoshiro256plus,       64)
+__krand_declare_alg(xoshiro256plusplus,   64)
+__krand_declare_alg(xoshiro256starstar,         64)
+    // splitmix64
+__krand_declare_alg(splitmix64, 64)
+
+
+#define __krand_next_definition(VALUE_SIZE) { return from+KRAND_ALG##VALUE_SIZE##_next(state)%(to-from); }
+
+// ready-to-use functions
+static inline int8  krand_next8 (KRAND_ALG32_state state, int8  from, int8  to) __krand_next_definition(32)
+static inline int16 krand_next16(KRAND_ALG32_state state, int16 from, int16 to) __krand_next_definition(32)
+static inline int32 krand_next32(KRAND_ALG32_state state, int32 from, int32 to) __krand_next_definition(32)
+static inline int64 krand_next64(KRAND_ALG64_state state, int64 from, int64 to) __krand_next_definition(64)
+
+// divides random number by 2^64 to return a value between 0 and 1
+static inline float32 krand_nextFloat32(KRAND_ALG32_state state) {return (uint32)KRAND_ALG32_next(state)/0xffffffff; }
+static inline float64 krand_nextFloat64(KRAND_ALG64_state state) {return KRAND_ALG64_next(state)/0xffffffff; }
+
+
+///@param chance (0-1.0) is probability of success
+bool fate(float chance);
+
+#if __cplusplus
+}
+#endif