Panda3DS/include/helpers.hpp

#pragma once
#include <iostream>
#include <vector>
#include <cstdarg>
#include <fstream>
#include "termcolor.hpp"

using u8 = std::uint8_t;
using u16 = std::uint16_t;
using u32 = std::uint32_t;
using u64 = std::uint64_t;
using usize = std::size_t;
using uint = unsigned int;

using s8 = std::int8_t;
using s16 = std::int16_t;
using s32 = std::int32_t;
using s64 = std::int64_t;

class Helpers {
public:
    [[noreturn]] static void panic(const char* fmt, ...) {
        std::va_list args;
        va_start(args, fmt);
        std::cout << termcolor::on_red << "[FATAL] ";
        std::vprintf (fmt, args);
        std::cout << termcolor::reset;
        std::cout << std::endl;
        va_end(args);

        exit(1);
    }

    static void warn(const char* fmt, ...) {
        return;
        std::va_list args;
        va_start(args, fmt);
        std::cout << termcolor::on_red << "[Warning] ";
        std::vprintf (fmt, args);
        std::cout << termcolor::reset;
        std::cout << "\n";
        va_end(args);
    }

    static std::vector <u8> loadROM(std::string directory) {
        std::ifstream file (directory, std::ios::binary);
        if (file.fail())
            panic("Couldn't read %s", directory.c_str());

        std::vector<u8> ROM;

        file.unsetf(std::ios::skipws);
        ROM.insert(ROM.begin(),
                  std::istream_iterator<uint8_t>(file),
                   std::istream_iterator<uint8_t>());

        file.close();

        printf ("%s loaded successfully\n", directory.c_str());
        return ROM;
    }

    static constexpr bool buildingInDebugMode() {
        #ifdef NDEBUG
            return false;
         #endif

         return true;
    }
    
    static void debug_printf (const char* fmt, ...) {
        if constexpr (buildingInDebugMode()) {
            std::va_list args;
            va_start(args, fmt);
            std::vprintf (fmt, args);
            va_end(args);
        }
    }

    /// Sign extend an arbitrary-size value to 32 bits
    static constexpr u32 inline signExtend32 (u32 value, u32 startingSize) {
        auto temp = (s32) value;
        auto bitsToShift = 32 - startingSize;
        return (u32) (temp << bitsToShift >> bitsToShift);
    }

    /// Sign extend an arbitrary-size value to 16 bits
    static constexpr u16 signExtend16 (u16 value, u32 startingSize) {
        auto temp = (s16) value;
        auto bitsToShift = 16 - startingSize;
        return (u16) (temp << bitsToShift >> bitsToShift);
    }

    /// Check if a bit "bit" of value is set
    static constexpr bool isBitSet (u32 value, int bit) {
        return (value >> bit) & 1;
    }

    /// rotate number right
    template <typename T>
    static constexpr T rotr (T value, int bits) {
        constexpr auto bitWidth = sizeof(T) * 8;
        bits &= bitWidth - 1;
        return (value >> bits) | (value << (bitWidth - bits));
    }

    // rotate number left
    template <typename T>
    static constexpr T rotl (T value, int bits) {
        constexpr auto bitWidth = sizeof(T) * 8;
        bits &= bitWidth - 1;
        return (value << bits) | (value >> (bitWidth - bits));
    }

    /// Used to make the compiler evaluate beeg loops at compile time for the tablegen
    template <typename T, T Begin,  class Func, T ...Is>
    static constexpr void static_for_impl( Func&& f, std::integer_sequence<T, Is...> ) {
    ( f( std::integral_constant<T, Begin + Is>{ } ),... );
    }

    template <typename T, T Begin, T End, class Func>
    static constexpr void static_for(Func&& f) {
        static_for_impl<T, Begin>( std::forward<Func>(f), std::make_integer_sequence<T, End - Begin>{ } );
    }

    static constexpr inline u8 get8BitColor (u8 colorRGB555) {
        return (colorRGB555 << 3) | (colorRGB555 >> 2);
    }

    // For values < 0x99
    static constexpr inline u8 incBCDByte(u8 value) {
        return ((value & 0xf) == 0x9) ? value + 7 : value + 1;
    }
};

// useful macros
// likely/unlikely
#ifdef __GNUC__
    #define likely(x)       __builtin_expect((x),1)
    #define unlikely(x)     __builtin_expect((x),0)
#else 
    #define likely(x)       (x)
    #define unlikely(x)     (x)
#endif