/// <summary>
///
/// </summary>
/// <param name="otherLine"></param>
/// <returns>Returns null to indicate lines are invalid or parralel.</returns>
public PointF?Intersection(SimpleLine otherLine)
{
float det = this.A * otherLine.B - otherLine.A * this.B;
if (det == 0)
{
return(null);
}
return(new PointF((otherLine.B * this.C - this.B * otherLine.C) / det,
(this.A * otherLine.C - otherLine.A * this.C) / det));
}
/// <summary>
/// Helper.
/// </summary>
protected bool TrySelectLine(Matrix transformationMatrix, bool allowLineSegmentOnly, PointF linePoint1, PointF linePoint2, PointF location, float absoluteSelectionMargin)
{
float lineSegmentLocation;
PointF intersectionPoint;
SimpleLine line = new SimpleLine(linePoint1, linePoint2);
float? distance = line.DistanceToPoint(location, out lineSegmentLocation, out intersectionPoint);
if (MathHelper.GetAbsoluteDistance(transformationMatrix, location, intersectionPoint) <= absoluteSelectionMargin)
{// Selection.
return(allowLineSegmentOnly == false || (lineSegmentLocation >= 0 && lineSegmentLocation <= 1));
}
return(false);
}
/// <summary>
/// Helper.
/// </summary>
protected bool TrySelectLine(Matrix transformationMatrix, bool allowLineSegmentOnly, PointF linePoint1, PointF linePoint2, PointF location, float absoluteSelectionMargin)
{
float lineSegmentLocation;
PointF intersectionPoint;
SimpleLine line = new SimpleLine(linePoint1, linePoint2);
float? distance = line.DistanceToPoint(location, out lineSegmentLocation, out intersectionPoint);
if (MathHelper.GetAbsoluteDistance(transformationMatrix, location, intersectionPoint) <= absoluteSelectionMargin)
{// Selection.
return allowLineSegmentOnly == false || (lineSegmentLocation >=0 && lineSegmentLocation <= 1);
}
return false;
}
/// <summary>
/// Helper - extends the given line segment to the ends of the drawing space.
/// </summary>
protected void StretchSegmentToDrawingSpace(ref PointF point1, ref PointF point2, RectangleF drawingSpace)
{
//if (_controlPoints.Count < 2)
//{
// return;
//}
SimpleLine thisLine = new SimpleLine(point1, point2);
PointF?[] intersectionPoints = new PointF?[4];
// The order is important, so preserve it.
intersectionPoints[0] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X, drawingSpace.Y), new PointF(drawingSpace.X, drawingSpace.Y + drawingSpace.Width)));
intersectionPoints[1] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X + drawingSpace.Width, drawingSpace.Y), new PointF(drawingSpace.X + drawingSpace.Width, drawingSpace.Y + drawingSpace.Width)));
intersectionPoints[2] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X, drawingSpace.Y), new PointF(drawingSpace.X + drawingSpace.Height, drawingSpace.Y)));
intersectionPoints[3] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X, drawingSpace.Y + drawingSpace.Height), new PointF(drawingSpace.X + drawingSpace.Height, drawingSpace.Y + drawingSpace.Height)));
if (intersectionPoints[0].HasValue == false)
{// Parallel to the 0,0 / 0, 10 line.
point1 = new PointF(point1.X, drawingSpace.Y);
point2 = new PointF(point1.X, drawingSpace.Y + drawingSpace.Height);
return;
}
else if (intersectionPoints[1].HasValue == false)
{// Parallel to the 0,0 / 10, 0 line.
point1 = new PointF(drawingSpace.X, point1.Y);
point2 = new PointF(drawingSpace.X + drawingSpace.Width, point1.Y);
return;
}
// Establish the best 2 points (shortest line = best performance).
int pointIndex1 = -1, pointIndex2 = -1;
for (int i = 0; i < intersectionPoints.Length; i++)
{
if (intersectionPoints[i].HasValue == false)
{
continue;
}
// Is the point within drawing space (Contains method does not deliver needed results).
float xCalculationErrorMargin = (drawingSpace.X + drawingSpace.Width) / 100;
float yCalculationErrorMargin = (drawingSpace.Y + drawingSpace.Height) / 100;
if (intersectionPoints[i].Value.X < drawingSpace.X - xCalculationErrorMargin
|| intersectionPoints[i].Value.X > drawingSpace.X + drawingSpace.Width + xCalculationErrorMargin
|| intersectionPoints[i].Value.Y < drawingSpace.Y - yCalculationErrorMargin
|| intersectionPoints[i].Value.Y > drawingSpace.Y + drawingSpace.Height + yCalculationErrorMargin)
{// Point outside.
continue;
}
// Point approved.
if (pointIndex1 < 0)
{
pointIndex1 = i;
}
else
{
pointIndex2 = i;
break;
}
}
if (pointIndex1 < 0 || pointIndex2 < 0)
{
// SystemMonitor.Error("This scenario should not happen.");
pointIndex1 = 0;
pointIndex2 = 1;
}
point1 = intersectionPoints[pointIndex1].Value;
point2 = intersectionPoints[pointIndex2].Value;
}
/// <summary>
///
/// </summary>
/// <param name="otherLine"></param>
/// <returns>Returns null to indicate lines are invalid or parralel.</returns>
public PointF? Intersection(SimpleLine otherLine)
{
float det = this.A * otherLine.B - otherLine.A * this.B;
if(det == 0)
{
return null;
}
return new PointF( (otherLine.B * this.C - this.B * otherLine.C) / det,
(this.A * otherLine.C - otherLine.A * this.C) / det);
}
/// <summary>
/// Helper - extends the given line segment to the ends of the drawing space.
/// </summary>
protected void StretchSegmentToDrawingSpace(ref PointF point1, ref PointF point2, RectangleF drawingSpace)
{
//if (_controlPoints.Count < 2)
//{
// return;
//}
SimpleLine thisLine = new SimpleLine(point1, point2);
PointF?[] intersectionPoints = new PointF?[4];
// The order is important, so preserve it.
intersectionPoints[0] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X, drawingSpace.Y), new PointF(drawingSpace.X, drawingSpace.Y + drawingSpace.Width)));
intersectionPoints[1] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X + drawingSpace.Width, drawingSpace.Y), new PointF(drawingSpace.X + drawingSpace.Width, drawingSpace.Y + drawingSpace.Width)));
intersectionPoints[2] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X, drawingSpace.Y), new PointF(drawingSpace.X + drawingSpace.Height, drawingSpace.Y)));
intersectionPoints[3] = thisLine.Intersection(new SimpleLine(new PointF(drawingSpace.X, drawingSpace.Y + drawingSpace.Height), new PointF(drawingSpace.X + drawingSpace.Height, drawingSpace.Y + drawingSpace.Height)));
if (intersectionPoints[0].HasValue == false)
{// Parallel to the 0,0 / 0, 10 line.
point1 = new PointF(point1.X, drawingSpace.Y);
point2 = new PointF(point1.X, drawingSpace.Y + drawingSpace.Height);
return;
}
else if (intersectionPoints[1].HasValue == false)
{// Parallel to the 0,0 / 10, 0 line.
point1 = new PointF(drawingSpace.X, point1.Y);
point2 = new PointF(drawingSpace.X + drawingSpace.Width, point1.Y);
return;
}
// Establish the best 2 points (shortest line = best performance).
int pointIndex1 = -1, pointIndex2 = -1;
for (int i = 0; i < intersectionPoints.Length; i++)
{
if (intersectionPoints[i].HasValue == false)
{
continue;
}
// Is the point within drawing space (Contains method does not deliver needed results).
float xCalculationErrorMargin = (drawingSpace.X + drawingSpace.Width) / 100;
float yCalculationErrorMargin = (drawingSpace.Y + drawingSpace.Height) / 100;
if (intersectionPoints[i].Value.X <drawingSpace.X - xCalculationErrorMargin ||
intersectionPoints[i].Value.X> drawingSpace.X + drawingSpace.Width + xCalculationErrorMargin ||
intersectionPoints[i].Value.Y <drawingSpace.Y - yCalculationErrorMargin ||
intersectionPoints[i].Value.Y> drawingSpace.Y + drawingSpace.Height + yCalculationErrorMargin)
{// Point outside.
continue;
}
// Point approved.
if (pointIndex1 < 0)
{
pointIndex1 = i;
}
else
{
pointIndex2 = i;
break;
}
}
if (pointIndex1 < 0 || pointIndex2 < 0)
{
// SystemMonitor.Error("This scenario should not happen.");
pointIndex1 = 0;
pointIndex2 = 1;
}
point1 = intersectionPoints[pointIndex1].Value;
point2 = intersectionPoints[pointIndex2].Value;
}
