/// <summary>
/// 两直线是否相交
/// </summary>
/// <param name="otherLine"></param>
/// <param name="intersectionPoint"></param>
/// <returns></returns>
public bool IntersectsWithLine(LineEquation otherLine, out Point intersectionPoint)
{
intersectionPoint = new Point(0, 0);
if (IsVertical && otherLine.IsVertical)
{
return(false);
}
if (IsVertical || otherLine.IsVertical)
{
intersectionPoint = GetIntersectionPointIfOneIsVertical(otherLine, this);
return(true);
}
double delta = A * otherLine.B - otherLine.A * B;
bool hasIntersection = Math.Abs(delta - 0) > 0.0001f;
if (hasIntersection)
{
double x = (otherLine.B * C - B * otherLine.C) / delta;
double y = (A * otherLine.C - otherLine.A * C) / delta;
intersectionPoint = new Point(TypeParse.StrToInt(x), TypeParse.StrToInt(y));;
}
/* float delta = A1*B2 - A2*B1;
* float x = (B2 * C1 - B1 * C2) / delta;
* float y = (A1 * C2 - A2 * C1) / delta;*/
return(hasIntersection);
}
private static Point GetIntersectionPointIfOneIsVertical(LineEquation line1, LineEquation line2)
{
LineEquation verticalLine = line2.IsVertical ? line2 : line1;
LineEquation nonVerticalLine = line2.IsVertical ? line1 : line2;
double y = (verticalLine.Start.X - nonVerticalLine.Start.X) *
(nonVerticalLine.End.Y - nonVerticalLine.Start.Y) /
((nonVerticalLine.End.X - nonVerticalLine.Start.X)) +
nonVerticalLine.Start.Y;
double x = verticalLine.Start.X;
return(new Point(TypeParse.StrToInt(x), TypeParse.StrToInt(y)));
}