kge/Cursor.cc

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///
/// \file Cursor.cc
/// \author kyle
/// \created 10/11/23
/// \brief
///
/// \section COPYRIGHT
/// Copyright 2023 K. Isom <kyle@imap.cc>
///
/// Permission to use, copy, modify, and/or distribute this software for
/// any purpose with or without fee is hereby granted, provided that the
/// above copyright notice and this permission notice appear in all copies.
///
/// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
/// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
/// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR
/// BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
/// OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
/// WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
/// ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
/// SOFTWARE.
///
#include "Cursor.h"
#include "Defs.h"
/// \todo kyle Can cursors be replaced with std::pair?
static std::pair<size_t, size_t>
orderedPair(size_t a, size_t b)
{
if (a > b) {
return {b, a};
}
return {a, b};
}
static size_t
isqrt(size_t n)
{
if (n < 2) {
return n;
}
size_t start = 0;
size_t end = n / 2;
size_t result = 0;
while (start <= end) {
auto middle = (start + end) >> 1;
result = middle * middle;
if (result == n) {
return middle;
}
if (result < n) {
start = middle + 1;
result = middle;
} else {
end = middle - 1;
result = middle;
}
}
return result;
}
Cursor Cursor::Update(const Cursor &c)
{
Cursor prev(this->x, this->y);
this->X(c.X());
this->Y(c.Y());
return prev;
}
size_t Cursor::Distance(const Cursor &c) const
{
auto xPair = orderedPair(this->x, c.X());
auto yPair = orderedPair(this->y, c.Y());
auto x0 = xPair.second - xPair.first;
x0 *= x0;
auto y0 = yPair.second - xPair.first;
y0 *= y0;
auto dist = x0 + y0;
return isqrt(dist);
}
std::ostream &operator<<(std::ostream &os, const Cursor &cursor)
{
os << cursor.X() << "," << cursor.Y();
return os;
}