libcruft-util/range.hpp
Danny Robson 0e3fa05f05 build: migrate from ipp files to pure hpp files
ipp files weren't a great way of keeping things clean, and IDEs have a
little trouble dealing with the split configuration. this simplifies
debugging a great deal.
2018-02-28 11:49:13 +11:00

137 lines
4.0 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2010-2015 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_RANGE_HPP
#define __UTIL_RANGE_HPP
#include <cstdint>
#include <ostream>
#include <limits>
#include <type_traits>
namespace util {
/**
* Represents a continuous range of values. Contains convenience functions
* and debugging checks.
*/
template <typename T>
struct range {
T lo;
T hi;
range (T _min, T _max);
T magnitude (void) const;
/// Check whether value falls within this range (inclusive)
bool contains (T val) const;
/// Check whether a range falls completely within (inclusive) this range
bool contains (const range <T> &r) const;
/// Check whether a range falls partially within (inclusive) this range
//bool includes (const range <T> &r) const;
/// interpolate between min-max using the unit position
T at (float) const;
/// Return the closest number that falls within the range.
T clamp (T val) const;
/// Expand the range to include this value if necessary
void expand (T val);
/// Normalise a number to [0, 1] within the range. Does not check
/// bounds, it is the caller's responsibility to clamp the result if
/// needed.
template <typename U>
U
normalise (T val) const
{
static_assert (std::is_floating_point<U>::value,
"normalise isn't implemented for integer types");
return static_cast<U> (val - lo) /
static_cast<U> ( hi - lo);
}
range& operator*= (T);
range operator* (T) const;
range& operator/= (T);
range operator/ (T) const;
range& operator+= (T);
range operator+ (T) const;
range& operator-= (T);
range operator- (T) const;
/// Return a pseudo-random uniformly distributed value within the range.
/// There are no statistical randomness guarantees whatsoever.
T random (void) const;
bool operator ==(const range<T>& rhs) const;
bool operator !=(const range<T>& rhs) const
{ return !(*this == rhs); }
/// A range which is guaranteed to contain all elements type T
static constexpr range<T> unlimited (void)
{
return {
std::numeric_limits<T>::has_infinity ? -std::numeric_limits<T>::infinity () :
std::numeric_limits<T>::lowest (),
std::numeric_limits<T>::has_infinity ? std::numeric_limits<T>::infinity () :
std::numeric_limits<T>::max ()
};
}
static constexpr range<T> max (void)
{
return {
std::numeric_limits<T>::lowest (),
std::numeric_limits<T>::max ()
};
}
/// A range which only contains elements between 0 and 1 inclusive
static constexpr range<T> unit (void)
{
return {
T {0}, T {1}
};
}
void sanity (void) const;
};
// convenience typedefs
typedef util::range<float> rangef;
typedef util::range<uintmax_t> rangeu;
typedef util::range<intmax_t> rangei;
// ostream operators
template <typename T>
std::ostream&
operator <<(std::ostream &os, const range<T> &rhs) {
os << '[' << rhs.min << ", " << rhs.max << ']';
return os;
}
}
#endif