/// <summary>
/// Determines if the given Point is near any of the lines in
/// Lines.LinesList. Sets HitLine to the first found or null if
/// none found.
/// </summary>
/// <param name="point">The input point in PictureBox coordinates.</param>
/// <returns>If found.</returns>
public bool hitTestLine(Point point)
{
if (ActiveMode != Mode.EDIT)
{
return(false);
}
Point imgPoint = imagePoint(point);
bool res;
HitLine = null;
HitPoint = null;
Debug.WriteLine("hitTestLine: ActiveMode=" + ActiveMode
+ " ZoomFactor=" + ZoomFactor + NL
+ " point=" + point + " imgPoint=" + imgPoint + NL
+ " LINE_WIDTH=" + LINE_WIDTH + " HIT_TOLERANCE=" + HIT_TOLERANCE);
foreach (Line line in Lines.LinesList)
{
// First check the points
// (Tolerance does not extend past the ends as it does transverse.)
Region region;
foreach (Point point1 in line.Points)
{
region = new Region(centeredSquare(point1, HIT_TOLERANCE));
res = region.IsVisible(imgPoint);
if (res)
{
HitPoint = new HitPoint(line, line.Points.IndexOf(point1));
HitLine = line;
return(true);
}
}
// Then check the lines.
using (var path = new GraphicsPath())
using (var pen = new Pen(Color.Black, HIT_TOLERANCE)) {
for (int i = 1; i < line.NPoints; i++)
{
path.AddLine(line.Points[i - 1], line.Points[i]);
}
res = path.IsOutlineVisible(imgPoint, pen);
if (res)
{
HitLine = line;
return(true);
}
}
}
return(false);
}
/// <summary>
/// Adds a point to the HitLine after the point corresponding to the
/// given Point and located between it and the next point at a distance
/// depending on the ratio of the distances between those points and
/// the diven point. If there is only one point in the line nothing will be done.
/// </summary>
/// <param name="point"></param>
public void addPoint(Point point)
{
if (HitLine == null)
{
return;
}
Point imgPoint = imagePoint(point);
List <Point> points = HitLine.Points;
int count = points.Count;
// Be sure there is more than one point
if (count <= 1)
{
return;
}
Point lineStart = INVALID_POINT;
bool res;
// First check the points
// (Tolerance does not extend past the ends as it does transverse.)
Region region;
foreach (Point point1 in points)
{
region = new Region(centeredSquare(point1, HIT_TOLERANCE));
res = region.IsVisible(imgPoint);
if (res)
{
lineStart = point1;
break;
}
}
// Then check the lines.
if (lineStart == INVALID_POINT)
{
for (int i = 1; i < HitLine.NPoints; i++)
{
using (var path = new GraphicsPath())
using (var pen = new Pen(Color.Black, HIT_TOLERANCE)) {
path.AddLine(points[i - 1], points[i]);
res = path.IsOutlineVisible(imgPoint, pen);
if (res)
{
lineStart = HitLine.Points[i - 1];
break;
}
}
}
}
if (lineStart == INVALID_POINT)
{
return;
}
int indexStart = points.IndexOf(lineStart);
if (indexStart == count - 1)
{
indexStart--;
}
if (points.IndexOf(lineStart) == count - 1)
{
lineStart = points[count - 2];
}
Point lineEnd = points[indexStart + 1];
double distance12 = lineLength(lineStart, lineEnd);
double distance01 = lineLength(lineStart, imgPoint);
double distance02 = lineLength(imgPoint, lineEnd);
double ratio;
if (distance01 == 0 && distance02 == 0)
{
ratio = 0;
}
else
{
ratio = distance01 / (distance01 + distance02);
}
int x2 = (int)Math.Round(lineStart.X + ratio * (lineEnd.X - lineStart.X));
int y2 = (int)Math.Round(lineStart.Y + ratio * (lineEnd.Y - lineStart.Y));
Point newPoint = new Point(x2, y2);
int newIndex = indexStart + 1;
points.Insert(indexStart + 1, newPoint);
HitPoint = new HitPoint(HitLine, newIndex);
}