109 lines
2.0 KiB
C++
109 lines
2.0 KiB
C++
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
|
|
#pragma once
|
|
|
|
#include "BLI_span.hh"
|
|
|
|
namespace blender {
|
|
|
|
/**
|
|
* An #OffsetSpan is a #Span with a constant offset that is added to every value when accessed.
|
|
* This allows e.g. storing multiple `int64_t` indices as an array of `int16_t` with an additional
|
|
* `int64_t` offset.
|
|
*/
|
|
template<typename T, typename BaseT> class OffsetSpan {
|
|
private:
|
|
/** Value that is added to every element in #data_ when accessed. */
|
|
T offset_ = 0;
|
|
/** Original span where each element is offset by #offset_. */
|
|
Span<BaseT> data_;
|
|
|
|
public:
|
|
OffsetSpan() = default;
|
|
OffsetSpan(const T offset, const Span<BaseT> data) : offset_(offset), data_(data) {}
|
|
|
|
/** \return Underlying span containing the values that are not offset. */
|
|
Span<BaseT> base_span() const
|
|
{
|
|
return data_;
|
|
}
|
|
|
|
T offset() const
|
|
{
|
|
return offset_;
|
|
}
|
|
|
|
bool is_empty() const
|
|
{
|
|
return data_.is_empty();
|
|
}
|
|
|
|
int64_t size() const
|
|
{
|
|
return data_.size();
|
|
}
|
|
|
|
T last(const int64_t n = 0) const
|
|
{
|
|
return offset_ + data_.last(n);
|
|
}
|
|
|
|
IndexRange index_range() const
|
|
{
|
|
return data_.index_range();
|
|
}
|
|
|
|
T operator[](const int64_t i) const
|
|
{
|
|
return T(data_[i]) + offset_;
|
|
}
|
|
|
|
OffsetSpan slice(const IndexRange &range) const
|
|
{
|
|
return {offset_, data_.slice(range)};
|
|
}
|
|
|
|
OffsetSpan slice(const int64_t start, const int64_t size) const
|
|
{
|
|
return {offset_, data_.slice(start, size)};
|
|
}
|
|
|
|
class Iterator {
|
|
private:
|
|
T offset_;
|
|
const BaseT *data_;
|
|
|
|
public:
|
|
Iterator(const T offset, const BaseT *data) : offset_(offset), data_(data) {}
|
|
|
|
Iterator &operator++()
|
|
{
|
|
data_++;
|
|
return *this;
|
|
}
|
|
|
|
T operator*() const
|
|
{
|
|
return T(*data_) + offset_;
|
|
}
|
|
|
|
friend bool operator!=(const Iterator &a, const Iterator &b)
|
|
{
|
|
BLI_assert(a.offset_ == b.offset_);
|
|
return a.data_ != b.data_;
|
|
}
|
|
};
|
|
|
|
Iterator begin() const
|
|
{
|
|
return {offset_, data_.begin()};
|
|
}
|
|
|
|
Iterator end() const
|
|
{
|
|
return {offset_, data_.end()};
|
|
}
|
|
};
|
|
|
|
} // namespace blender
|