/***To check whether the point is in a line segment***/
public bool InLine(CLineSegment lineSegment)
{
bool bInline = false;
double Ax, Ay, Bx, By, Cx, Cy;
Bx = lineSegment.EndPoint.X;
By = lineSegment.EndPoint.Y;
Ax = lineSegment.StartPoint.X;
Ay = lineSegment.StartPoint.Y;
Cx = this.m_dCoordinate_X;
Cy = this.m_dCoordinate_Y;
double L = lineSegment.GetLineSegmentLength();
double s = Math.Abs(((Ay - Cy) * (Bx - Ax) - (Ax - Cx) * (By - Ay)) / (L * L));
if (Math.Abs(s - 0) < ConstantValue.SmallValue)
{
if ((SamePoints(this, lineSegment.StartPoint)) ||
(SamePoints(this, lineSegment.EndPoint)))
{
bInline = true;
}
else if ((Cx < lineSegment.GetXmax()) &&
(Cx > lineSegment.GetXmin()) &&
(Cy < lineSegment.GetYmax()) &&
(Cy > lineSegment.GetYmin()))
{
bInline = true;
}
}
return(bInline);
}
/********************************************************
* To check whether 2 lines segments have an intersection
*********************************************************/
public bool IntersectedWith(CLineSegment line)
{
double x1 = this.m_startPoint.X;
double y1 = this.m_startPoint.Y;
double x2 = this.m_endPoint.X;
double y2 = this.m_endPoint.Y;
double x3 = line.m_startPoint.X;
double y3 = line.m_startPoint.Y;
double x4 = line.m_endPoint.X;
double y4 = line.m_endPoint.Y;
double de = (y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1);
//if de<>0 then //lines are not parallel
if (Math.Abs(de - 0) > ConstantValue.SmallValue) //not parallel
{
double ua = ((x4 - x3) * (y1 - y3) - (y4 - y3) * (x1 - x3)) / de;
double ub = ((x2 - x1) * (y1 - y3) - (y2 - y1) * (x1 - x3)) / de;
if ((ua > 0) && (ua < 1))
{
return(true);
}
else
{
return(false);
}
}
else //lines are parallel
{
return(false);
}
}
/***To check whether the point is in a line segment***/
public bool InLine(CLineSegment lineSegment)
{
bool bInline=false;
double Ax, Ay, Bx, By, Cx, Cy;
Bx=lineSegment.EndPoint.X;
By=lineSegment.EndPoint.Y;
Ax=lineSegment.StartPoint.X;
Ay=lineSegment.StartPoint.Y;
Cx=this.m_dCoordinate_X;
Cy=this.m_dCoordinate_Y;
double L=lineSegment.GetLineSegmentLength();
double s=Math.Abs(((Ay-Cy)*(Bx-Ax)-(Ax-Cx)*(By-Ay))/(L*L));
if (Math.Abs(s-0)<ConstantValue.SmallValue)
{
if ((SamePoints(this, lineSegment.StartPoint)) ||
(SamePoints(this, lineSegment.EndPoint)))
bInline=true;
else if ((Cx<lineSegment.GetXmax())
&& (Cx>lineSegment.GetXmin())
&&(Cy< lineSegment.GetYmax())
&& (Cy>lineSegment.GetYmin()))
bInline=true;
}
return bInline;
}
/***Check whether this line is in a longer line***/
public bool InLine(CLineSegment longerLineSegment)
{
bool bInLine = false;
if ((m_startPoint.InLine(longerLineSegment)) &&
(m_endPoint.InLine(longerLineSegment)))
{
bInLine = true;
}
return(bInLine);
}
/************************************************
* Offset the line segment to generate a new line segment
* If the offset direction is along the x-axis or y-axis,
* Parameter is true, other wise it is false
* ***********************************************/
public CLineSegment OffsetLine(double distance, bool rightOrDown)
{
//offset a line with a given distance, generate a new line
//rightOrDown=true means offset to x incress direction,
// if the line is horizontal, offset to y incress direction
CLineSegment line;
CPoint2D newStartPoint = new CPoint2D();
CPoint2D newEndPoint = new CPoint2D();
double alphaInRad = this.GetLineAngle(); // 0-PI
if (rightOrDown)
{
if (this.HorizontalLine()) //offset to y+ direction
{
newStartPoint.X = this.m_startPoint.X;
newStartPoint.Y = this.m_startPoint.Y + distance;
newEndPoint.X = this.m_endPoint.X;
newEndPoint.Y = this.m_endPoint.Y + distance;
line = new CLineSegment(newStartPoint, newEndPoint);
}
else //offset to x+ direction
{
if (Math.Sin(alphaInRad) > 0)
{
newStartPoint.X = m_startPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
newStartPoint.Y = m_startPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));
newEndPoint.X = m_endPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
newEndPoint.Y = m_endPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));
line = new CLineSegment(
newStartPoint, newEndPoint);
}
else //sin(FalphaInRad)<0
{
newStartPoint.X = m_startPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
newStartPoint.Y = m_startPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));
newEndPoint.X = m_endPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
newEndPoint.Y = m_endPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));
line = new CLineSegment(
newStartPoint, newEndPoint);
}
}
} //{rightOrDown}
else //leftOrUp
{
if (this.HorizontalLine()) //offset to y directin
{
newStartPoint.X = m_startPoint.X;
newStartPoint.Y = m_startPoint.Y - distance;
newEndPoint.X = m_endPoint.X;
newEndPoint.Y = m_endPoint.Y - distance;
line = new CLineSegment(
newStartPoint, newEndPoint);
}
else //offset to x directin
{
if (Math.Sin(alphaInRad) >= 0)
{
newStartPoint.X = m_startPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
newStartPoint.Y = m_startPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));
newEndPoint.X = m_endPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
newEndPoint.Y = m_endPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));
line = new CLineSegment(
newStartPoint, newEndPoint);
}
else //sin(FalphaInRad)<0
{
newStartPoint.X = m_startPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
newStartPoint.Y = m_startPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));
newEndPoint.X = m_endPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
newEndPoint.Y = m_endPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));
line = new CLineSegment(
newStartPoint, newEndPoint);
}
}
}
return(line);
}
/**********************************************************
To check the Pt is in the Triangle or not.
If the Pt is in the line or is a vertex, then return true.
If the Pt is out of the Triangle, then return false.
This method is used for triangle only.
***********************************************************/
private bool TriangleContainsPoint(CPoint2D[] trianglePts, CPoint2D pt)
{
if (trianglePts.Length!=3)
return false;
for (int i=trianglePts.GetLowerBound(0);
i<trianglePts.GetUpperBound(0); i++)
{
if (pt.EqualsPoint(trianglePts[i]))
return true;
}
bool bIn=false;
CLineSegment line0=new CLineSegment(trianglePts[0],trianglePts[1]);
CLineSegment line1=new CLineSegment(trianglePts[1],trianglePts[2]);
CLineSegment line2=new CLineSegment(trianglePts[2],trianglePts[0]);
if (pt.InLine(line0)||pt.InLine(line1)
||pt.InLine(line2))
bIn=true;
else //point is not in the lines
{
double dblArea0=CPolygon.PolygonArea(new CPoint2D[]
{trianglePts[0],trianglePts[1], pt});
double dblArea1=CPolygon.PolygonArea(new CPoint2D[]
{trianglePts[1],trianglePts[2], pt});
double dblArea2=CPolygon.PolygonArea(new CPoint2D[]
{trianglePts[2],trianglePts[0], pt});
if (dblArea0>0)
{
if ((dblArea1 >0) &&(dblArea2>0))
bIn=true;
}
else if (dblArea0<0)
{
if ((dblArea1 < 0) && (dblArea2< 0))
bIn=true;
}
}
return bIn;
}
/************************************************
* Offset the line segment to generate a new line segment
* If the offset direction is along the x-axis or y-axis,
* Parameter is true, other wise it is false
* ***********************************************/
public CLineSegment OffsetLine(double distance, bool rightOrDown)
{
//offset a line with a given distance, generate a new line
//rightOrDown=true means offset to x incress direction,
// if the line is horizontal, offset to y incress direction
CLineSegment line;
CPoint2D newStartPoint=new CPoint2D();
CPoint2D newEndPoint=new CPoint2D();
double alphaInRad= this.GetLineAngle(); // 0-PI
if (rightOrDown)
{
if (this.HorizontalLine()) //offset to y+ direction
{
newStartPoint.X =this.m_startPoint.X;
newStartPoint.Y=this.m_startPoint.Y + distance;
newEndPoint.X =this.m_endPoint.X;
newEndPoint.Y=this.m_endPoint.Y + distance;
line=new CLineSegment(newStartPoint,newEndPoint);
}
else //offset to x+ direction
{
if (Math.Sin(alphaInRad)>0)
{
newStartPoint.X=m_startPoint.X + Math.Abs(distance*Math.Sin(alphaInRad));
newStartPoint.Y=m_startPoint.Y - Math.Abs(distance* Math.Cos(alphaInRad)) ;
newEndPoint.X=m_endPoint.X + Math.Abs(distance*Math.Sin(alphaInRad));
newEndPoint.Y=m_endPoint.Y - Math.Abs(distance* Math.Cos(alphaInRad)) ;
line= new CLineSegment(
newStartPoint, newEndPoint);
}
else //sin(FalphaInRad)<0
{
newStartPoint.X=m_startPoint.X + Math.Abs(distance*Math.Sin(alphaInRad));
newStartPoint.Y=m_startPoint.Y + Math.Abs(distance* Math.Cos(alphaInRad)) ;
newEndPoint.X=m_endPoint.X + Math.Abs(distance*Math.Sin(alphaInRad));
newEndPoint.Y=m_endPoint.Y + Math.Abs(distance* Math.Cos(alphaInRad)) ;
line=new CLineSegment(
newStartPoint, newEndPoint);
}
}
}//{rightOrDown}
else //leftOrUp
{
if (this.HorizontalLine()) //offset to y directin
{
newStartPoint.X=m_startPoint.X;
newStartPoint.Y=m_startPoint.Y - distance;
newEndPoint.X=m_endPoint.X;
newEndPoint.Y=m_endPoint.Y - distance;
line=new CLineSegment(
newStartPoint, newEndPoint);
}
else //offset to x directin
{
if (Math.Sin(alphaInRad)>=0)
{
newStartPoint.X=m_startPoint.X - Math.Abs(distance*Math.Sin(alphaInRad));
newStartPoint.Y=m_startPoint.Y + Math.Abs(distance* Math.Cos(alphaInRad)) ;
newEndPoint.X=m_endPoint.X - Math.Abs(distance*Math.Sin(alphaInRad));
newEndPoint.Y=m_endPoint.Y + Math.Abs(distance* Math.Cos(alphaInRad)) ;
line=new CLineSegment(
newStartPoint, newEndPoint);
}
else //sin(FalphaInRad)<0
{
newStartPoint.X=m_startPoint.X - Math.Abs(distance*Math.Sin(alphaInRad));
newStartPoint.Y=m_startPoint.Y - Math.Abs(distance* Math.Cos(alphaInRad)) ;
newEndPoint.X=m_endPoint.X - Math.Abs(distance*Math.Sin(alphaInRad));
newEndPoint.Y=m_endPoint.Y - Math.Abs(distance* Math.Cos(alphaInRad)) ;
line=new CLineSegment(
newStartPoint, newEndPoint);
}
}
}
return line;
}
/********************************************************
To check whether 2 lines segments have an intersection
*********************************************************/
public bool IntersectedWith(CLineSegment line)
{
double x1=this.m_startPoint.X;
double y1=this.m_startPoint.Y;
double x2=this.m_endPoint.X;
double y2=this.m_endPoint.Y;
double x3=line.m_startPoint.X;
double y3=line.m_startPoint.Y;
double x4=line.m_endPoint.X;
double y4=line.m_endPoint.Y;
double de=(y4-y3)*(x2-x1)-(x4-x3)*(y2-y1);
//if de<>0 then //lines are not parallel
if (Math.Abs(de-0)<ConstantValue.SmallValue) //not parallel
{
double ua=((x4-x3)*(y1-y3)-(y4-y3)*(x1-x3))/de;
double ub=((x2-x1)*(y1-y3)-(y2-y1)*(x1-x3))/de;
if ((ub> 0) && (ub<1))
return true;
else
return false;
}
else //lines are parallel
return false;
}
/***Check whether this line is in a longer line***/
public bool InLine(CLineSegment longerLineSegment)
{
bool bInLine=false;
if ((m_startPoint.InLine(longerLineSegment)) &&
(m_endPoint.InLine(longerLineSegment)))
bInLine=true;
return bInLine;
}
