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#pragma once
#include "point2d.hpp"
#include "robust_orientation.hpp"
#include "triangle2d.hpp"
#include "base/assert.hpp"
#include "base/base.hpp"
#include "base/buffer_vector.hpp"
#include "base/logging.hpp"
#include "base/math.hpp"
#include "std/algorithm.hpp"
namespace covering
{
// Result of an intersection between object and cell.
enum CellObjectIntersection
{
// No intersection. It is important, that its value is 0, so one can do if (intersection) ... .
CELL_OBJECT_NO_INTERSECTION = 0,
CELL_OBJECT_INTERSECT = 1,
CELL_INSIDE_OBJECT = 2,
OBJECT_INSIDE_CELL = 3
};
template <class CellIdT>
inline CellObjectIntersection IntersectCellWithLine(CellIdT const cell,
m2::PointD const & a,
m2::PointD const & b)
{
pair<uint32_t, uint32_t> const xy = cell.XY();
uint32_t const r = cell.Radius();
m2::PointD const cellCorners[4] =
{
m2::PointD(xy.first - r, xy.second - r),
m2::PointD(xy.first - r, xy.second + r),
m2::PointD(xy.first + r, xy.second + r),
m2::PointD(xy.first + r, xy.second - r)
};
for (int i = 0; i < 4; ++i)
if (m2::robust::SegmentsIntersect(a, b, cellCorners[i], cellCorners[i == 0 ? 3 : i - 1]))
return CELL_OBJECT_INTERSECT;
if (xy.first - r <= a.x && a.x <= xy.first + r && xy.second - r <= a.y && a.y <= xy.second + r)
return OBJECT_INSIDE_CELL;
return CELL_OBJECT_NO_INTERSECTION;
}
template <class CellIdT>
CellObjectIntersection IntersectCellWithTriangle(
CellIdT const cell, m2::PointD const & a, m2::PointD const & b, m2::PointD const & c)
{
CellObjectIntersection const i1 = IntersectCellWithLine(cell, a, b);
if (i1 == CELL_OBJECT_INTERSECT)
return CELL_OBJECT_INTERSECT;
CellObjectIntersection const i2 = IntersectCellWithLine(cell, b, c);
if (i2 == CELL_OBJECT_INTERSECT)
return CELL_OBJECT_INTERSECT;
CellObjectIntersection const i3 = IntersectCellWithLine(cell, c, a);
if (i3 == CELL_OBJECT_INTERSECT)
return CELL_OBJECT_INTERSECT;
// At this point either:
// 1. Triangle is inside cell.
// 2. Cell is inside triangle.
// 3. Cell and triangle do not intersect.
ASSERT_EQUAL(i1, i2, (cell, a, b, c));
ASSERT_EQUAL(i2, i3, (cell, a, b, c));
ASSERT_EQUAL(i3, i1, (cell, a, b, c));
if (i1 == OBJECT_INSIDE_CELL || i2 == OBJECT_INSIDE_CELL || i3 == OBJECT_INSIDE_CELL)
return OBJECT_INSIDE_CELL;
pair<uint32_t, uint32_t> const xy = cell.XY();
if (m2::IsPointStrictlyInsideTriangle(m2::PointD(xy.first, xy.second), a, b, c))
return CELL_INSIDE_OBJECT;
return CELL_OBJECT_NO_INTERSECTION;
}
template <class CellIdT, class CellIdContainerT, typename IntersectF>
void CoverObject(IntersectF const & intersect, uint64_t cellPenaltyArea, CellIdContainerT & out,
int cellDepth, CellIdT cell)
{
if (cell.Level() == cellDepth - 1)
{
out.push_back(cell);
return;
}
uint64_t const cellArea = my::sq(uint64_t(1 << (cellDepth - 1 - cell.Level())));
CellObjectIntersection const intersection = intersect(cell);
if (intersection == CELL_OBJECT_NO_INTERSECTION)
return;
if (intersection == CELL_INSIDE_OBJECT || cellPenaltyArea >= cellArea)
{
out.push_back(cell);
return;
}
buffer_vector<CellIdT, 32> subdiv;
for (uint8_t i = 0; i < 4; ++i)
CoverObject(intersect, cellPenaltyArea, subdiv, cellDepth, cell.Child(i));
uint64_t subdivArea = 0;
for (size_t i = 0; i < subdiv.size(); ++i)
subdivArea += my::sq(uint64_t(1 << (CellIdT::DEPTH_LEVELS - 1 - subdiv[i].Level())));
ASSERT(!subdiv.empty(), (cellPenaltyArea, out, cell));
if (subdiv.empty() || cellPenaltyArea * (int(subdiv.size()) - 1) >= cellArea - subdivArea)
out.push_back(cell);
else
for (size_t i = 0; i < subdiv.size(); ++i)
out.push_back(subdiv[i]);
}
} // namespace covering
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