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#pragma once
#include <nall/stdint.hpp>
namespace nall {
template<uint bits> inline auto uclamp(const uintmax x) -> uintmax {
enum : uintmax { b = 1ull << (bits - 1), y = b * 2 - 1 };
return y + ((x - y) & -(x < y)); //min(x, y);
}
template<uint bits> inline auto uclip(const uintmax x) -> uintmax {
enum : uintmax { b = 1ull << (bits - 1), m = b * 2 - 1 };
return (x & m);
}
template<uint bits> inline auto sclamp(const intmax x) -> intmax {
enum : intmax { b = 1ull << (bits - 1), m = b - 1 };
return (x > m) ? m : (x < -b) ? -b : x;
}
template<uint bits> inline auto sclip(const intmax x) -> intmax {
enum : uintmax { b = 1ull << (bits - 1), m = b * 2 - 1 };
return ((x & m) ^ b) - b;
}
namespace bit {
constexpr inline auto mask(const char* s, uintmax sum = 0) -> uintmax {
return (
*s == '0' || *s == '1' ? mask(s + 1, (sum << 1) | 1) :
*s == ' ' || *s == '_' ? mask(s + 1, sum) :
*s ? mask(s + 1, sum << 1) :
sum
);
}
constexpr inline auto test(const char* s, uintmax sum = 0) -> uintmax {
return (
*s == '0' || *s == '1' ? test(s + 1, (sum << 1) | (*s - '0')) :
*s == ' ' || *s == '_' ? test(s + 1, sum) :
*s ? test(s + 1, sum << 1) :
sum
);
}
//lowest(0b1110) == 0b0010
constexpr inline auto lowest(const uintmax x) -> uintmax {
return x & -x;
}
//clear_lowest(0b1110) == 0b1100
constexpr inline auto clearLowest(const uintmax x) -> uintmax {
return x & (x - 1);
}
//set_lowest(0b0101) == 0b0111
constexpr inline auto setLowest(const uintmax x) -> uintmax {
return x | (x + 1);
}
//count number of bits set in a byte
inline auto count(uintmax x) -> uint {
uint count = 0;
do count += x & 1; while(x >>= 1);
return count;
}
//return index of the first bit set (or zero of no bits are set)
//first(0b1000) == 3
inline auto first(uintmax x) -> uint {
uint first = 0;
while(x) { if(x & 1) break; x >>= 1; first++; }
return first;
}
//round up to next highest single bit:
//round(15) == 16, round(16) == 16, round(17) == 32
inline auto round(uintmax x) -> uintmax {
if((x & (x - 1)) == 0) return x;
while(x & (x - 1)) x &= x - 1;
return x << 1;
}
}
}
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