libcruft-util/region.hpp

237 lines
6.9 KiB
C++
Raw Normal View History

2011-05-23 17:18:52 +10:00
/*
2015-04-13 18:05:28 +10:00
* 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
2011-05-23 17:18:52 +10:00
*
2015-04-13 18:05:28 +10:00
* http://www.apache.org/licenses/LICENSE-2.0
2011-05-23 17:18:52 +10:00
*
2015-04-13 18:05:28 +10:00
* 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.
2011-05-23 17:18:52 +10:00
*
* Copyright 2010-2017 Danny Robson <danny@nerdcruft.net>
2011-05-23 17:18:52 +10:00
*/
#ifndef CRUFT_UTIL_REGION_HPP
#define CRUFT_UTIL_REGION_HPP
2011-05-23 17:18:52 +10:00
#include "./extent.hpp"
#include "./point.hpp"
#include "./vector.hpp"
#include "./types/traits.hpp"
2018-03-22 16:10:06 +11:00
#include <iosfwd>
2011-08-15 20:10:43 +10:00
namespace util {
/**
* A two-dimensional rectangle, with size and position.
*/
template <size_t S, typename T>
2011-08-29 14:40:05 +10:00
struct region {
using extent_t = util::extent<S,T>;
using point_t = util::point<S,T>;
2015-03-02 18:48:09 +11:00
using value_type = T;
//---------------------------------------------------------------------
static constexpr size_t dimension = S;
static constexpr size_t elements = extent_t::elements + point_t::elements;
point_t p;
extent_t e;
//---------------------------------------------------------------------
region () = default;
explicit region (extent_t);
region (point_t, extent_t);
region (point_t, point_t);
2011-05-23 17:18:52 +10:00
2015-09-21 15:33:58 +10:00
//---------------------------------------------------------------------
template <typename U>
constexpr region<S,U>
cast (void) const
{
return {
p.template cast<U> (),
e.template cast<U> ()
};
}
2015-09-21 15:33:58 +10:00
//---------------------------------------------------------------------
T area (void) const;
T diameter (void) const;
2015-03-02 18:48:09 +11:00
extent_t magnitude (void) const;
extent_t magnitude (extent_t);
2015-02-17 16:24:16 +11:00
2011-08-15 20:10:43 +10:00
bool empty (void) const;
//---------------------------------------------------------------------
point_t base (void) const;
point_t away (void) const;
point_t centre (void) const;
point_t closest (point_t) const;
//---------------------------------------------------------------------
// exclusive of borders
bool intersects (region<S,T>) const;
2015-01-21 23:33:35 +11:00
// Compute binary region combinations
region intersection (region<S,T>) const;
// Test if a region lies completely within our space
bool covers (region<S,T>) const noexcept;
/// Test if a point lies within our space. Inclusive of borders
constexpr
bool
inclusive (point<S,T> q) const noexcept
{
return all (p <= q && p + e >= q);
}
/// test if a point lies within our space, exclusive of the
/// bottom-right border
constexpr bool
exclusive (point<S,T> q) const noexcept
{
return all (p <= q && p + e > q);
}
// Move a point to be within the region bounds
point_t constrain (point_t) const noexcept;
//---------------------------------------------------------------------
2015-01-21 23:37:00 +11:00
// Compute a region `mag` units into the region
region inset (T mag) const;
region inset (vector<S,T> mag) const;
2015-02-04 15:44:51 +11:00
region expand (T mag) const;
region expand (vector<S,T>) const;
2015-01-21 23:37:00 +11:00
2015-02-20 15:26:59 +11:00
// arithmetic operators
region operator+ (vector<S,T>) const;
region operator- (vector<S,T>) const;
2015-02-20 15:26:59 +11:00
2015-01-21 23:33:35 +11:00
// Logical comparison operators
bool operator ==(region<S,T> rhs) const;
bool operator !=(region<S,T> rhs) const
2011-08-15 20:10:43 +10:00
{ return !(*this == rhs); }
2011-05-23 17:18:52 +10:00
2015-01-21 23:33:35 +11:00
// Utility constants
static constexpr region<S,T> max (void)
{
return {
util::point <S,T> {std::numeric_limits<T>::lowest () / 2},
util::extent<S,T> {std::numeric_limits<T>::max ()}
};
}
static constexpr region<S,T> unit (void)
{
return {
point_t::origin (),
extent_t {1}
};
}
2012-06-15 16:38:57 +10:00
static constexpr region<S,T> zero (void)
{ return { point_t {0}, extent_t {0} }; }
2017-07-31 15:42:05 +10:00
class iterator {
public:
using iterator_category = std::forward_iterator_tag;
using difference_type = std::size_t;
using value_type = point_t;
using pointer = value_type*;
using reference = value_type&;
iterator (point_t _lo, point_t _hi):
cursor (_lo),
lo (_lo),
hi (_hi)
{ ; }
const point_t& operator* (void) const& { return cursor; }
iterator&
operator++ (void)
{
cursor[0] += 1;
for (size_t s = 0; s < S-1; ++s) {
if (cursor[s] <= hi[s])
return *this;
cursor[s] = lo[s];
cursor[s+1]++;
}
return *this;
}
bool operator== (const iterator &rhs) const { return cursor == rhs.cursor; }
bool operator!= (const iterator &rhs) const { return cursor != rhs.cursor; }
private:
point_t cursor, lo, hi;
};
auto step (void) const
{
point_t last = p;
last[S-1] = (p + e)[S-1] + 1;
return util::view {
iterator { p, p + e },
iterator { last, p + e }
};
};
void sanity (void) const;
};
///////////////////////////////////////////////////////////////////////////
/// constructs the minimal region that encompasses a region and a point.
template <typename T, size_t S>
region<S,T>
make_union (region<S,T> r, point<S,T> p)
{
const auto p0 = select (r.p < p, r.p, p);
const auto p1 = select (r.away () > p, r.away (), p);
return { p0, p1 };
}
2018-05-30 14:35:03 +10:00
template <size_t S, typename T, typename GeneratorT>
util::point<S,T>
sample (region<S,T> shape, GeneratorT &&gen)
{
return shape.p + sample (shape.e, std::forward<GeneratorT> (gen)).template as<util::vector> ();
}
///////////////////////////////////////////////////////////////////////////
2016-10-25 20:02:19 +11:00
template <typename T> using region2 = region<2,T>;
template <typename T> using region3 = region<3,T>;
2016-10-25 20:02:19 +11:00
using region2u = region2<unsigned>;
using region2i = region2<int>;
using region2f = region2<float>;
using region2d = region2<double>;
///////////////////////////////////////////////////////////////////////////
template <size_t S, typename T>
std::ostream& operator<< (std::ostream&, const util::region<S,T>&);
2011-08-15 20:10:43 +10:00
}
2011-05-23 17:18:52 +10:00
2015-01-16 14:42:56 +11:00
#endif