//Вычисление пробной функции
//(для всех точек окна знак должен быть одинаков для каждой стороны многоугольника)
public bool probn(Window wnd, Figure f)
{
List <Line> lines = f.lines;
double m, b;
int lt = 0, ld = 0, rt = 0, rd = 0;
for (int i = 0; i < lines.Count; i++)
{
if (lines[i].first.y > wnd.yUp && lines[i].second.y > wnd.yUp ||
lines[i].first.y < wnd.yDown && lines[i].second.y < wnd.yDown)
{
continue;
}
if ((lines[i].second.x - lines[i].first.x) != 0)
{
if (lines[i].first.x > wnd.xRight && lines[i].second.x > wnd.xRight ||
lines[i].first.x < wnd.xLeft && lines[i].second.x < wnd.xLeft)
{
continue;
}
m = (lines[i].second.y - lines[i].first.y) / (lines[i].second.x - lines[i].first.x);
b = lines[i].second.y - m * lines[i].second.x;
lt = 0; ld = 0; rt = 0; rd = 0;
if ((wnd.yUp - m * wnd.xLeft - b) >= 0)
{
lt = 1;
}
else
{
lt = -1;
}
if ((wnd.yDown - m * wnd.xLeft - b) >= 0)
{
ld = 1;
}
else
{
ld = -1;
}
if ((wnd.yUp - m * wnd.xRight - b) >= 0)
{
rt = 1;
}
else
{
rt = -1;
}
if ((wnd.yDown - m * wnd.xRight - b) >= 0)
{
rd = 1;
}
else
{
rd = -1;
}
if (Math.Abs(lt + ld + rt + rd) != 4)
{
return(false);
}
}
else
{
//если x1=x2, то в знаменателе 0
m = -lines[i].first.x;
lt = 0; ld = 0; rt = 0; rd = 0;
if ((wnd.xRight + m) >= 0)
{
lt = 1;
}
else
{
lt = -1;
}
if ((wnd.xLeft + m) >= 0)
{
ld = 1;
}
else
{
ld = -1;
}
if (Math.Abs(lt + ld) != 2)
{
return(false);
}
}
}
return(true);
}
private void getBorderFigure(ref double x_max, ref double x_min, ref double y_max, ref double y_min, Figure figure)
{
x_max = -max_coord; x_min = max_coord; y_max = -max_coord; y_min = max_coord;
foreach (var line in figure.lines)
{
if (line.first.x > x_max)
{
x_max = line.first.x;
}
if (line.first.x < x_min)
{
x_min = line.first.x;
}
if (line.second.x > x_max)
{
x_max = line.second.x;
}
if (line.second.x < x_min)
{
x_min = line.second.x;
}
if (line.first.y > y_max)
{
y_max = line.first.y;
}
if (line.first.y < y_min)
{
y_min = line.first.y;
}
if (line.second.y > y_max)
{
y_max = line.second.y;
}
if (line.second.y < y_min)
{
y_min = line.second.y;
}
}
}
