jabyengine/include/PSX/Auxiliary/bits.hpp

#ifndef __JABYENGINE_BITS_HPP__
#define __JABYENGINE_BITS_HPP__
#include "../jabyengine_defines.h"
#include "types.hpp"

namespace JabyEngine {
    namespace bit {
        namespace value {
            template<typename T>
            static constexpr T set_normalized(T raw_value, T value, size_t start_bit, size_t length);
        }
    }

    struct ClearBit {
        uint16_t pos;

        constexpr ClearBit(uint16_t bit_pos) : pos(bit_pos) {
        }
    };

    struct Bit {
        uint16_t pos;

        constexpr Bit(uint16_t bit_pos) : pos(bit_pos) {
        }

        constexpr ClearBit operator!() const {
            return ClearBit(this->pos);
        }
    };

    struct BitRange {
        template<typename T>
        using RangeValuePair = pair<BitRange, T>;

        uint16_t pos;
        uint16_t length;

        constexpr BitRange(uint16_t pos, uint16_t length) : pos(pos), length(length) {
        }

        static constexpr BitRange from_to(uint16_t first_bit, uint16_t last_bit) {
            return BitRange(first_bit, (last_bit - first_bit) + 1);
        }

        template<typename T>
        constexpr RangeValuePair<T> with(T value) const {
            return {*this, value};
        }

        template<typename T>
        constexpr T as_value(T value) const {
            return bit::value::set_normalized(static_cast<T>(0), value, this->pos, this->length);
        }

        template<typename T>
        constexpr RangeValuePair<T> range_max() const {
            return BitRange::with<T>((1 << this->length) - 1);
        }
    };

    namespace bit {
        template<typename T>
        static constexpr T clear(T raw_value, size_t bit) {
            return (raw_value & ~(1 << bit));
        }

        template<typename T>
        static constexpr T clear(T raw_value, Bit bit) {
            return clear(raw_value, bit.pos);
        }

        template<typename T>
        static constexpr T set(T raw_value, size_t bit) {
            return (raw_value | (1 << bit));
        }

        template<typename T>
        static constexpr T set(T raw_value, Bit bit) {
            return set(raw_value, bit.pos);
        }

        template<typename T>
        static constexpr T set(T raw_value, ClearBit bit) {
            return clear(raw_value, bit.pos);
        }

        template<typename T>
        static constexpr bool is_set(T raw_value, size_t bit) {
            return static_cast<bool>(raw_value & (1 << bit));
        }

        template<typename T>
        static constexpr bool is_set(T raw_value, Bit bit) {
            return is_set(raw_value, bit.pos);
        }

        namespace value {
            namespace helper {
                template<typename T>
                static constexpr T crop_value(T raw_value, size_t length) {
                    return (raw_value & ((1 << length) - 1));
                }

                template<typename T>
                static constexpr T range_mask(size_t start_bit, size_t length) {
                    return (((1 << length) - 1) << start_bit);
                }
            }

            template<typename T>
            static constexpr T clear_normalized(T raw_value, size_t start_bit, size_t length) {
                return (raw_value & ~helper::range_mask<T>(start_bit, length));
            }

            template<typename T>
            static constexpr T set_normalized(T raw_value, T value, size_t start_bit, size_t length) {
                return (clear_normalized(raw_value, start_bit, length) | (helper::crop_value(value, length) << start_bit));
            }

            template<typename T>
            static constexpr T set_normalized(T raw_value, BitRange bits, T value) {
                return set_normalized(raw_value, value, bits.pos, bits.length);
            }

            template<typename T, typename S>
            static constexpr T set_normalized(T raw_value, const BitRange::RangeValuePair<S> &value_pair) {
                return set_normalized(raw_value, value_pair.first, static_cast<T>(value_pair.second));
            }

            template<typename T>
            static constexpr T get_normalized(T raw_value, size_t start_bit, size_t length) {
                return helper::crop_value((raw_value & helper::range_mask<T>(start_bit, length)) >> start_bit, length);
            }

            template<typename T>
            static constexpr T get_normalized(T raw_value, BitRange range) {
                return get_normalized(raw_value, range.pos, range.length);
            }
        }

        template<typename S, typename T>
        static constexpr S cast(T value) {
            return *reinterpret_cast<S*>(&value);
        }
    }
}

#define __start_end_bit2_start_length(start_bit, end_bit) start_bit, (end_bit - start_bit + 1)
#endif //!__JABYENGINE_BITS_HPP__