public Vector3?Intersect(LinePathSegment other) //xy: point, z: distance along line
{
if (this.Length == 0 || other.Length == 0)
{
return(null);
}
var epsilon = 0.0001f;
Vector2 a = Direction;
Vector2 b = other.Direction;
Vector2 c = Start - other.Start;
//percent of line 1 where we intersect with line 2
float ip = 1 / (-b.X * a.Y + a.X * b.Y); //projection
float t = (b.X * c.Y - b.Y * c.X) * ip;
//percent of line 2 where we intersect line 1
float ip2 = 1 / (-a.X * b.Y + b.X * a.Y);
float s = (a.X * (-c.Y) - a.Y * (-c.X)) * ip2;
if (float.IsNaN(t) || t < -epsilon || t > 1 + epsilon || float.IsNaN(s) || s < -epsilon || s > 1 + epsilon)
{
return(null);
}
return(new Vector3(Direction * t + Start, t * Length));
}
public LinePath(List <Vector2> line)
{
for (int i = 0; i < line.Count - 1; i++)
{
var seg = new LinePathSegment(line[i], line[i + 1]);
Length += seg.Length;
Segments.Add(seg);
}
}
public void PrepareJoins()
{
LinePathSegment last = null;
foreach (var line in Segments)
{
if (last != null)
{
last.EndNormal = line.StartNormal = Vector2.Normalize(last.EndNormal + line.StartNormal);
}
last = line;
}
}
public List <LinePath> Split(float dist, float gap)
{
var result = new List <LinePath>();
var startGap = dist - gap / 2;
var endGap = dist + gap / 2;
bool before = 0 < startGap;
LinePath current = new LinePath();
if (before)
{
current.SharpStart = SharpStart;
current.SharpEnd = true;
current.StartOffset = StartOffset;
}
else
{
current.SharpStart = true;
current.SharpEnd = SharpEnd;
current.StartOffset = StartOffset + endGap;
}
current.TemplateNum = TemplateNum;
float soFar = 0;
foreach (var segment in Segments)
{
if (before)
{
if (soFar + segment.Length <= startGap)
{
//add this segment
current.Segments.Add(segment);
}
else
{
//this segment extends over the gap.
//an additional segment must be added to reach the start gap
if (soFar != startGap && segment.Length != 0)
{
var bridge = new LinePathSegment(segment.Start, Vector2.Lerp(segment.Start, segment.End, (startGap - soFar) / segment.Length));
bridge.StartNormal = segment.StartNormal;
current.Segments.Add(bridge);
}
current.Length = current.Segments.Sum(x => x.Length);
result.Add(current);
current = new LinePath();
current.SharpStart = true;
current.SharpEnd = SharpEnd;
current.StartOffset = StartOffset + endGap;
current.TemplateNum = TemplateNum;
before = false;
}
}
if (!before)
{
if (current.Segments.Count == 0)
{
//waiting to get to a segment that ends after the gap.
if (soFar + segment.Length > endGap)
{
var bridge = new LinePathSegment(Vector2.Lerp(segment.Start, segment.End, (endGap - soFar) / segment.Length), segment.End);
bridge.EndNormal = segment.EndNormal;
current.Segments.Add(bridge);
}
}
else
{
//add this segment
current.Segments.Add(segment);
}
}
soFar += segment.Length;
}
current.Length = current.Segments.Sum(x => x.Length);
result.Add(current);
return(result);
}