internal static IEnumerable <GeoLine> GetLines(IEnumerable <Point> points, double distance, bool isClosed)
{
var firstLine = default(GeoLine?);
var lastPoint = default(Point);
var isFirst = true;
foreach (var point in points)
{
if (isFirst)
{
isFirst = false;
}
else
{
var start = lastPoint;
var end = point;
var vec = GetVector(end - start) * distance;
start += vec;
end += vec;
var line = new GeoLine(start, end);
if (isClosed && firstLine == null)
{
firstLine = line;
}
yield return(line);
}
lastPoint = point;
}
if (firstLine.HasValue)
{
yield return(firstLine.Value);
}
}
public Point?Cross(GeoLine line)
{
var crossPoint = default(Point?);
var d = A * line.B - B * line.A;
if (!Utilities.IsZero(d))
{
var p = new Point();
p.X = (line.C * B - C * line.B) / d;
p.Y = -(line.C * A - C * line.A) / d;
crossPoint = p;
}
return(crossPoint);
}
public double AngleTo(GeoLine line)
{
return(Vector.AngleBetween(_direction, line._direction));
}
internal static IGraphic Extend(IList <Point> points, double distance, JointType jointType, IEnumerable <Segment> segments, bool isClosed)
{
var tuples = new List <Tuple <IGraphic, GeoLine?> >();
var lastLine = default(GeoLine?);
var lastOrigin = default(GeoLine?);
var index = 0;
foreach (var line in GetLines(points, distance, isClosed))
{
if (lastLine.HasValue)
{
var beforeOrigin = lastOrigin.Value;
var before = lastLine.Value;
var after = line;
var angle = before.AngleTo(after);
if (Utilities.IsZero(Math.Abs(angle)))
{
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicLine(before.P1, before.P2), beforeOrigin));
}
else
{
var flag = Utilities.IsClose(Math.Abs(angle), 180);
if (angle < 0 ^ distance > 0)
{
switch (jointType)
{
case JointType.Flat:
{
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicLine(before.P1, before.P2), beforeOrigin));
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicLine(before.P2, after.P1), null));
}
break;
case JointType.Sharp:
{
if (flag)
{
return(null);
}
var cp = before.Cross(after);
if (!cp.HasValue)
{
return(null);
}
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicLine(before.P1, cp.Value), beforeOrigin));
after = new GeoLine(cp.Value, after.P2);
}
break;
case JointType.Rounded:
{
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicLine(before.P1, before.P2), beforeOrigin));
var center = points[index];
var radius = Math.Abs(distance);
var startV = before.P2 - center;
var endV = after.P1 - center;
var startAngle = Vector.AngleBetween(new Vector(1, 0), startV);
var endAngle = startAngle + Vector.AngleBetween(startV, endV);
if (endAngle > startAngle)
{
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicArc(center, radius, startAngle, endAngle), null));
}
else
{
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicArc(center, radius, endAngle, startAngle, true), null));
}
}
break;
}
}
else
{
if (flag)
{
return(null);
}
var cp = before.Cross(after);
if (cp.HasValue && before.IsOnLine(cp.Value) && after.IsOnLine(cp.Value))
{
before = new GeoLine(before.P1, cp.Value);
after = new GeoLine(cp.Value, after.P2);
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicLine(before.P1, before.P2), beforeOrigin));
}
else
{
return(null);
}
}
}
lastLine = after;
}
else
{
lastLine = line;
}
lastOrigin = line;
index++;
}
if (lastLine.HasValue)
{
if (!isClosed)
{
tuples.Add(new Tuple <IGraphic, GeoLine?>(new GraphicLine(lastLine.Value.P1, lastLine.Value.P2), lastOrigin));
}
else
{
var tuple = tuples[0];
var firstLine = (GraphicLine)tuple.Item1;
var p1 = lastLine.Value.P1;
var p2 = firstLine.P2;
var vec1 = p2 - firstLine.P1;
var vec2 = p2 - p1;
if (Utilities.IsSameDirection(vec1, vec2))
{
firstLine = new GraphicLine(p1, p2);
tuples[0] = new Tuple <IGraphic, GeoLine?>(firstLine, tuple.Item2);
}
else
{
return(null);
}
}
}
if (tuples.Count > 0)
{
if (segments != null)
{
var graphics = new List <IGraphic>();
foreach (var segment in segments)
{
var started = false;
var subGraphics = new List <IGraphic>();
var currentOffset = 0d;
var startOffset = segment.StartOffset;
var endOffset = segment.EndOffset;
foreach (var tuple in tuples)
{
var item = tuple.Item2;
if (item.HasValue)
{
var line = item.Value;
var offset = currentOffset + line.Length;
if (currentOffset < endOffset && offset > startOffset)
{
if (currentOffset >= startOffset && offset <= endOffset)
{
subGraphics.Add(tuple.Item1);
started = true;
}
else
{
var brk = false;
var newLine = (GraphicLine)tuple.Item1;
var sp = newLine.Start;
var ep = newLine.End;
if (startOffset > currentOffset)
{
var p = line.GetPoint(startOffset - currentOffset);
if (newLine.IsOnLine(p))
{
sp = p;
started = true;
}
else
{
var vec1 = newLine.End - p;
var vec2 = newLine.End - newLine.Start;
started = Utilities.IsSameDirection(vec1, vec2);
}
}
else
{
started = true;
}
if (endOffset < offset)
{
var p = line.GetPoint(endOffset - currentOffset);
if (newLine.IsOnLine(p))
{
ep = p;
}
else
{
var vec1 = p - newLine.Start;
var vec2 = newLine.End - newLine.Start;
started = Utilities.IsSameDirection(vec1, vec2);
}
brk = true;
}
if (started)
{
subGraphics.Add(new GraphicLine(sp, ep));
}
if (brk)
{
break;
}
}
}
else if (currentOffset >= endOffset)
{
if (subGraphics.Count > 0)
{
graphics.Add(new GraphicCompositeCurve(subGraphics, true));
}
break;
}
currentOffset = offset;
}
else if (started)
{
subGraphics.Add(tuple.Item1);
}
}
if (subGraphics.Count > 0)
{
graphics.Add(new GraphicCompositeCurve(subGraphics, true));
}
}
if (graphics.Count > 0)
{
return(new GraphicCompositeCurve(graphics, false));
}
}
else
{
return(new GraphicCompositeCurve(tuples.Select(graphic => graphic.Item1), true));
}
}
return(null);
}