122 lines
3.5 KiB
C++
122 lines
3.5 KiB
C++
/*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* Copyright 2010-2020 Danny Robson <danny@nerdcruft.net>
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*/
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#pragma once
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#include <cstdint>
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#include <limits>
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#include <type_traits>
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#include <iosfwd>
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namespace cruft {
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/**
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* Represents a continuous range of values. Contains convenience functions
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* and debugging checks.
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*/
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template <typename T>
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struct range {
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T lo;
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T hi;
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range (T _min, T _max);
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T magnitude (void) const;
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/// Check whether value falls within this range (inclusive)
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bool contains (T val) const;
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/// Check whether a range falls completely within (inclusive) this range
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bool contains (const range <T> &r) const;
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/// Check whether a range falls partially within (inclusive) this range
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//bool includes (const range <T> &r) const;
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/// interpolate between min-max using the unit position
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T at (float) const;
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/// Return the closest number that falls within the range.
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T clamp (T val) const;
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/// Expand the range to include this value if necessary
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void expand (T val);
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/// Normalise a number to [0, 1] within the range. Does not check
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/// bounds, it is the caller's responsibility to clamp the result if
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/// needed.
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template <typename U>
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U
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normalise (T val) const
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{
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static_assert (std::is_floating_point<U>::value,
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"normalise isn't implemented for integer types");
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return static_cast<U> (val - lo) /
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static_cast<U> ( hi - lo);
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}
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range& operator*= (T);
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range operator* (T) const;
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range& operator/= (T);
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range operator/ (T) const;
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range& operator+= (T);
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range operator+ (T) const;
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range& operator-= (T);
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range operator- (T) const;
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/// Return a pseudo-random uniformly distributed value within the range.
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/// There are no statistical randomness guarantees whatsoever.
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T random (void) const;
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bool operator ==(const range<T>& rhs) const;
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bool operator !=(const range<T>& rhs) const
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{ return !(*this == rhs); }
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/// A range which is guaranteed to contain all elements type T
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static constexpr range<T> unlimited (void)
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{
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return {
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std::numeric_limits<T>::has_infinity ? -std::numeric_limits<T>::infinity () :
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std::numeric_limits<T>::lowest (),
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std::numeric_limits<T>::has_infinity ? std::numeric_limits<T>::infinity () :
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std::numeric_limits<T>::max ()
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};
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}
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static constexpr range<T> max (void)
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{
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return {
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std::numeric_limits<T>::lowest (),
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std::numeric_limits<T>::max ()
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};
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}
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/// A range which only contains elements between 0 and 1 inclusive
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static constexpr range<T> unit (void)
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{
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return {
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T {0}, T {1}
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};
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}
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void sanity (void) const;
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};
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// convenience typedefs
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typedef cruft::range<float> rangef;
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typedef cruft::range<uintmax_t> rangeu;
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typedef cruft::range<intmax_t> rangei;
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// ostream operators
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template <typename T>
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std::ostream&
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operator <<(std::ostream &os, const range<T> &);
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}
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