src/common_types/prng.cpp - main - SneakBug8/Project-Alice

src/common_types/prng.cpp
80 строк3 KB
Katy
Update prng.cpp
24 ноя 2024, 09:04
24 ноя 2024, 09:04ce520a3
#include "prng.hpp"
#include "system_state.hpp"

#include "random123/philox.h"

namespace rng {

uint64_t get_random(sys::state const& state, uint32_t value_in) { // try to populate as many bits of value_in as you can
	r123::Philox4x32 rng;
	r123::Philox4x32::ctr_type c = {state.current_date.value, value_in, 0, 0 };
	r123::Philox4x32::key_type k = {state.game_seed, 0x3918CA23};

	r123::Philox4x32::ctr_type r = rng(c, k);

	return (uint64_t(r[0]) << 32) | uint64_t(r[1]);
}
uint64_t get_random(sys::state const& state, uint32_t value_in_hi, uint32_t value_in_lo) {
	r123::Philox4x32 rng;
	r123::Philox4x32::ctr_type c = {value_in_hi, value_in_lo, 0, 0};
	r123::Philox4x32::key_type k = {state.game_seed, 0x3918CA23 };

	r123::Philox4x32::ctr_type r = rng(c, k);

	return (uint64_t(r[0]) << 32) | uint64_t(r[1]);
}
random_pair get_random_pair(sys::state const& state, uint32_t value_in) { // each call natively generates 128 random bits anyways

	r123::Philox4x32 rng;
	r123::Philox4x32::ctr_type c = {state.current_date.value, value_in, 0, 0 };
	r123::Philox4x32::key_type k = {state.game_seed, 0x3918CA23 };

	r123::Philox4x32::ctr_type r = rng(c, k);

	return random_pair{(uint64_t(r[0]) << 32) | uint64_t(r[1]), (uint64_t(r[2]) << 32) | uint64_t(r[3])};
}
random_pair get_random_pair(sys::state const& state, uint32_t value_in_hi, uint32_t value_in_lo) { // each call natively generates 128 random bits anyways

	r123::Philox4x32 rng;
	r123::Philox4x32::ctr_type c = {value_in_hi, value_in_lo, 0, 0 };
	r123::Philox4x32::key_type k = {state.game_seed, 0x3918CA23 };

	r123::Philox4x32::ctr_type r = rng(c, k);

	return random_pair{(uint64_t(r[0]) << 32) | uint64_t(r[1]), (uint64_t(r[2]) << 32) | uint64_t(r[3])};
}
uint32_t reduce(uint32_t value_in, uint32_t upper_bound) {
	return uint32_t((uint64_t(value_in) * uint64_t(upper_bound)) >> 32);
}

float get_random_float(sys::state const& state, uint32_t value_in) {
	r123::Philox4x32 rng;
	r123::Philox4x32::ctr_type c = {state.current_date.value, value_in, 0, 0 };
	r123::Philox4x32::key_type k = {state.game_seed, 0x3918CA23};
	r123::Philox4x32::ctr_type r = rng(c, k);
	//
	union {
		uint32_t u;
		float f;
	} pattern;
	pattern.u = 0x3f800000;
	pattern.u |= 0x7fffff & r[1];
	return pattern.f - 1.0f;
}

float get_random_float(sys::state const& state, uint32_t value_in_hi, uint32_t value_in_lo) {
	r123::Philox4x32 rng;
	r123::Philox4x32::ctr_type c = {value_in_hi, value_in_lo, 0, 0 };
	r123::Philox4x32::key_type k = {state.game_seed, 0x3918CA23};
	r123::Philox4x32::ctr_type r = rng(c, k);
	//
	union {
		uint32_t u;
		float f;
	} pattern;
	pattern.u = 0x3f800000;
	pattern.u |= 0x7fffff & r[1];
	return pattern.f - 1.0f;
}

} // namespace rng