Working util::range type and bounded range-scale API!

Fortune for cpprng's current commit: Future blessing − 末吉
lib
Avril 3 years ago
parent 5d69550fff
commit a9bc96294a
Signed by: flanchan
GPG Key ID: 284488987C31F630

@ -1,10 +1,94 @@
#pragma once #pragma once
#include <utility> #include <utility>
#include <tuple>
#include <common.h> #include <common.h>
namespace util {
enum class bound
{
Inclusive = 0,
Exclusive
};
struct bounds
{
bound low, high;
};
constexpr inline const bounds default_bounds { bound::Inclusive, bound::Exclusive };
template<typename T, bounds B = default_bounds>
struct range
{
constexpr static inline const bounds Bounds = B;
using type = T;
//constexpr inline range(T start, T end) : start(start), end(end){}
constexpr inline range(T&& start, T&& end) : start(std::move(start)), end(std::move(end)){}
constexpr inline range(const T& start, const T& end) : start(start), end(end){}
constexpr inline range(range<T>&& move) : start(std::move(move.start)), end(std::move(move.end)) {}
constexpr inline range(const range<T>& copy) : start(copy.start), end(copy.end){}
constexpr inline ~range() {}
constexpr inline auto length() const { return end-start; }
constexpr inline auto length(const T& from) const { return from - start; }
constexpr inline bool negative() const { return length() < 0; }
constexpr inline range<T>& normalise() {
if(negative()) std::swap(start, end);
return *this;
}
template<usize I>
requires (I < 2)
constexpr inline T& get() { return I ? end : start; }
template<usize I>
requires (I < 2)
constexpr inline const T& get() const { return I ? end : start; }
constexpr inline bool contains(const T& value) const
{
return (Bounds.low == bound::Exclusive
? value > start
: value >= start) &&
(Bounds.high == bound::Exclusive
? value < end
: value <= end);
}
constexpr inline void clamp(T& value) const
{
if constexpr(Bounds.low == bound::Exclusive) {
if (value <= start) value = start + 1;
} else if (value < start) value = start;
if constexpr(Bounds.high == bound::Exclusive) {
if (value >= end) value = end - 1;
} else if (value > end) value = end;
}
// Scale the `value` from this range to another one (of a compatable type).
template<typename U>
constexpr inline auto scale(const range<U>& to, T value)
{
clamp(value);
const auto diff = length(value);
const f64 fract = f64(diff) / f64(length());
const auto diff2 = typename range<U>::type(fract * f64(to.length()));
return to.start + diff2;
}
constexpr inline auto scale(const range<T>& to, T value) { return scale<T>(to, value); }
T start, end;
};
}
// -- old
#if 0
namespace util{ namespace util{
enum class bound enum class bound
{ {
@ -89,3 +173,4 @@ struct range final
constexpr static inline const bounds default_bounds() { return { bound::Inclusive, bound::Exclusive }; } constexpr static inline const bounds default_bounds() { return { bound::Inclusive, bound::Exclusive }; }
} }
#endif

@ -53,5 +53,7 @@ N_INTS
void __() void __()
{ {
util::range<int> test(-10, 20); util::range<int> test(-10, 20);
test.scale({ 100, 200 }, 5); util::range<long> test2(-1000, 2000);
test.scale(test2, 5);
} }

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