libcruft-util/region.hpp
Danny Robson 72f631ab4b region: remove `expanded' function
we're trying to move away from mutating operators.

also, we do the bad thing of just renaming the non-mutating operator
given it appears no one is using the mutating operator in our code bases
anyway...
2017-08-09 17:28:53 +10:00

138 lines
4.3 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_REGION_HPP
#define __UTIL_REGION_HPP
#include "extent.hpp"
#include "point.hpp"
#include "vector.hpp"
#include "types/traits.hpp"
#include <ostream>
namespace util {
/**
* A two-dimensional rectangle, with size and position.
*/
template <size_t S, typename T>
struct region {
using extent_t = util::extent<S,T>;
using point_t = util::point<S,T>;
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);
//---------------------------------------------------------------------
template <typename U>
constexpr region<S,U> cast (void) const;
//---------------------------------------------------------------------
T area (void) const;
T diameter (void) const;
extent_t magnitude (void) const;
extent_t magnitude (extent_t);
void scale (T factor);
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;
//---------------------------------------------------------------------
// Point and region relation queries
bool includes (point_t) const; // inclusive of borders
bool contains (point_t) const; // exclusive of borders
bool intersects (region<S,T>) const; // exclusive of borders
bool has (point_t) const noexcept; // inclusive of top and left borders
// Move a point to be within the region bounds
void constrain (point_t&) const;
point_t constrained (point_t) const;
// Compute binary region combinations
region intersection (region<S,T>) const;
//---------------------------------------------------------------------
// Compute a region `mag` units into the region
region inset (T mag) const;
region inset (vector<S,T> mag) const;
region expand (T mag) const;
region expand (vector<S,T>) const;
// arithmetic operators
region operator+ (vector<S,T>) const;
region operator- (vector<S,T>) const;
// Logical comparison operators
bool operator ==(region<S,T> rhs) const;
bool operator !=(region<S,T> rhs) const
{ return !(*this == rhs); }
// Utility constants
static constexpr region<S,T> max (void);
static constexpr region<S,T> unit (void);
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 };
}
template <typename T> using region2 = region<2,T>;
template <typename T> using region3 = region<3,T>;
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>&);
}
#include "region.ipp"
#endif