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Support non-modifying chunked_map::at

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This commit is contained in:
Nikita Lisitsa 2021-03-10 14:12:29 +03:00
parent 8284ea51bd
commit 7b84cb0b1f
1 changed files with 21 additions and 1 deletions
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22
libs/pcg/include/psemek/pcg/chunked_map.hpp
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@ -5,6 +5,7 @@
#include <psemek/geom/box.hpp>
#include <unordered_map>
#include <optional>
namespace psemek::pcg
{
@ -19,7 +20,7 @@ namespace psemek::pcg
, generator_(std::move(generator))
{}
T const & operator()(geom::vector<int, N> p)
T & operator()(geom::point<int, N> p)
{
geom::vector<int, N> ip;
for (std::size_t i = 0; i < N; ++i)
@ -45,6 +46,25 @@ namespace psemek::pcg
return it->second(t);
}
std::optional<T> at(geom::point<int, N> p) const
{
geom::vector<int, N> ip;
for (std::size_t i = 0; i < N; ++i)
{
ip[i] = (p[i] >= 0) ? (p[i] / chunk_size_) : -((- p[i] + chunk_size_ - 1) / chunk_size_);
}
auto it = chunks_.find(ip);
if (it == chunks_.end())
return std::nullopt;
std::array<std::size_t, N> t;
for (std::size_t i = 0; i < N; ++i)
t[i] = p[i] - ip[i] * chunk_size_;
return it->second(t);
}
private:
int const chunk_size_;
generator_func generator_;