PrusaSlicer-NonPlainar/src/libslic3r/MTUtils.hpp

170 lines
4.9 KiB
C++

#ifndef MTUTILS_HPP
#define MTUTILS_HPP
#include <atomic> // for std::atomic_flag and memory orders
#include <mutex> // for std::lock_guard
#include <functional> // for std::function
#include <utility> // for std::forward
#include <vector>
#include <algorithm>
#include <cmath>
#include "libslic3r.h"
namespace Slic3r {
/// Handy little spin mutex for the cached meshes.
/// Implements the "Lockable" concept
class SpinMutex
{
std::atomic_flag m_flg;
static const /*constexpr*/ auto MO_ACQ = std::memory_order_acquire;
static const /*constexpr*/ auto MO_REL = std::memory_order_release;
public:
inline SpinMutex() { m_flg.clear(MO_REL); }
inline void lock() { while (m_flg.test_and_set(MO_ACQ)) ; }
inline bool try_lock() { return !m_flg.test_and_set(MO_ACQ); }
inline void unlock() { m_flg.clear(MO_REL); }
};
/// A wrapper class around arbitrary object that needs thread safe caching.
template<class T> class CachedObject
{
public:
// Method type which refreshes the object when it has been invalidated
using Setter = std::function<void(T &)>;
private:
T m_obj; // the object itself
bool m_valid; // invalidation flag
SpinMutex m_lck; // to make the caching thread safe
// the setter will be called just before the object's const value is
// about to be retrieved.
std::function<void(T &)> m_setter;
public:
// Forwarded constructor
template<class... Args>
inline CachedObject(Setter fn, Args &&... args)
: m_obj(std::forward<Args>(args)...), m_valid(false), m_setter(fn)
{}
// invalidate the value of the object. The object will be refreshed at
// the next retrieval (Setter will be called). The data that is used in
// the setter function should be guarded as well during modification so
// the modification has to take place in fn.
inline void invalidate(std::function<void()> fn)
{
std::lock_guard<SpinMutex> lck(m_lck);
fn();
m_valid = false;
}
// Get the const object properly updated.
inline const T &get()
{
std::lock_guard<SpinMutex> lck(m_lck);
if (!m_valid) {
m_setter(m_obj);
m_valid = true;
}
return m_obj;
}
};
/// A very simple range concept implementation with iterator-like objects.
template<class It> class Range
{
It from, to;
public:
// The class is ready for range based for loops.
It begin() const { return from; }
It end() const { return to; }
// The iterator type can be obtained this way.
using Type = It;
Range() = default;
Range(It &&b, It &&e)
: from(std::forward<It>(b)), to(std::forward<It>(e))
{}
// Some useful container-like methods...
inline size_t size() const { return end() - begin(); }
inline bool empty() const { return size() == 0; }
};
template<class C> bool all_of(const C &container)
{
return std::all_of(container.begin(),
container.end(),
[](const typename C::value_type &v) {
return static_cast<bool>(v);
});
}
template<class T> struct remove_cvref
{
using type =
typename std::remove_cv<typename std::remove_reference<T>::type>::type;
};
template<class T> using remove_cvref_t = typename remove_cvref<T>::type;
/// Exactly like Matlab https://www.mathworks.com/help/matlab/ref/linspace.html
template<class T, class I, class = IntegerOnly<I>>
inline std::vector<T> linspace_vector(const ArithmeticOnly<T> &start,
const T &stop,
const I &n)
{
std::vector<T> vals(n, T());
T stride = (stop - start) / n;
size_t i = 0;
std::generate(vals.begin(), vals.end(), [&i, start, stride] {
return start + i++ * stride;
});
return vals;
}
template<size_t N, class T>
inline std::array<ArithmeticOnly<T>, N> linspace_array(const T &start, const T &stop)
{
std::array<T, N> vals = {T()};
T stride = (stop - start) / N;
size_t i = 0;
std::generate(vals.begin(), vals.end(), [&i, start, stride] {
return start + i++ * stride;
});
return vals;
}
/// A set of equidistant values starting from 'start' (inclusive), ending
/// in the closest multiple of 'stride' less than or equal to 'end' and
/// leaving 'stride' space between each value.
/// Very similar to Matlab [start:stride:end] notation.
template<class T>
inline std::vector<ArithmeticOnly<T>> grid(const T &start,
const T &stop,
const T &stride)
{
std::vector<T> vals(size_t(std::ceil((stop - start) / stride)), T());
int i = 0;
std::generate(vals.begin(), vals.end(), [&i, start, stride] {
return start + i++ * stride;
});
return vals;
}
} // namespace Slic3r
#endif // MTUTILS_HPP