static Vector2[] LineBezierThicknessIntersect(BezierSegment seg, float thickness, Vector2 lineFrom, Vector2 lineTo, out float distanceToIntersection, out Vector2 intersection)
{
Vector2 tan = ShapeUtils.EvalTangent(seg, 0.0f);
Vector2 nrm = Vector2.Perpendicular(tan);
Vector2 lastPoint = seg.P0 + nrm * thickness;
distanceToIntersection = 0.0f;
intersection = new Vector2(float.PositiveInfinity, float.PositiveInfinity);
float stepT = 0.01f;
float t = 0;
while (t < 1.0f)
{
t += stepT;
var point = ShapeUtils.EvalFull(seg, t, out tan, out nrm) + nrm * thickness;
intersection = ShapeUtils.IntersectLines(lineFrom, lineTo, lastPoint, point);
if (PointOnLineIsWithinSegment(lastPoint, point, intersection))
{
distanceToIntersection += (lastPoint - intersection).magnitude;
return(new Vector2[] { lastPoint, point });
}
distanceToIntersection += (lastPoint - point).magnitude;
lastPoint = point;
}
return(null);
}
static void AddSegment(BezierSegment segment, float toT, float halfThickness, JoiningInfo[] joinInfo, float segmentLengthSoFar, List <Vector2> verts, List <UInt16> inds)
{
Vector2 tanTo, normTo;
Vector2 posTo = ShapeUtils.EvalFull(segment, toT, out tanTo, out normTo);
Vector2 posThickness = posTo + normTo * halfThickness;
Vector2 negThickness = posTo + normTo * -halfThickness;
if (joinInfo != null)
{
if ((joinInfo[0] != null) && (segmentLengthSoFar < joinInfo[0].InnerCornerDistFromStart))
{
if (joinInfo[0].RoundPosThickness)
{
negThickness = joinInfo[0].InnerCornerVertex;
}
else
{
posThickness = joinInfo[0].InnerCornerVertex;
}
}
if ((joinInfo[1] != null) && (segmentLengthSoFar > joinInfo[1].InnerCornerDistToEnd))
{
if (joinInfo[1].RoundPosThickness)
{
negThickness = joinInfo[1].InnerCornerVertex;
}
else
{
posThickness = joinInfo[1].InnerCornerVertex;
}
}
}
System.Diagnostics.Debug.Assert(verts.Count >= 2);
int indexStart = verts.Count - 2;
verts.Add(posThickness);
verts.Add(negThickness);
inds.Add((UInt16)(indexStart + 0));
inds.Add((UInt16)(indexStart + 3));
inds.Add((UInt16)(indexStart + 1));
inds.Add((UInt16)(indexStart + 0));
inds.Add((UInt16)(indexStart + 2));
inds.Add((UInt16)(indexStart + 3));
}
static void GenerateTip(BezierSegment segment, bool atStart, float t, PathEnding ending, float halfThickness, TessellationOptions tessellateOptions, List <Vector2> verts, List <UInt16> inds)
{
// The tip includes the vertices at the end itself
Vector2 tan, nrm;
var pos = ShapeUtils.EvalFull(segment, t, out tan, out nrm);
int indexStart = verts.Count;
switch (ending)
{
case PathEnding.Chop:
if (atStart)
{
verts.Add(pos + nrm * halfThickness);
verts.Add(pos - nrm * halfThickness);
}
else
{
// Not much, path segments are always expected to be generated perpendicular to the path
// at the segment point location, so we don't have to do anything for the ending
}
break;
case PathEnding.Square:
if (atStart)
{
verts.Add(pos + nrm * halfThickness - tan * halfThickness);
verts.Add(pos - nrm * halfThickness - tan * halfThickness);
verts.Add(pos + nrm * halfThickness);
verts.Add(pos - nrm * halfThickness);
inds.Add((UInt16)(indexStart + 0));
inds.Add((UInt16)(indexStart + 3));
inds.Add((UInt16)(indexStart + 1));
inds.Add((UInt16)(indexStart + 0));
inds.Add((UInt16)(indexStart + 2));
inds.Add((UInt16)(indexStart + 3));
}
else
{
// Relying on the last two vertices, and just adding two of our own here
verts.Add(pos + nrm * halfThickness + tan * halfThickness);
verts.Add(pos - nrm * halfThickness + tan * halfThickness);
inds.Add((UInt16)(indexStart + 0 - 2));
inds.Add((UInt16)(indexStart + 3 - 2));
inds.Add((UInt16)(indexStart + 1 - 2));
inds.Add((UInt16)(indexStart + 0 - 2));
inds.Add((UInt16)(indexStart + 2 - 2));
inds.Add((UInt16)(indexStart + 3 - 2));
}
break;
case PathEnding.Round:
float arcSign = atStart ? -1 : 1;
int arcSegments = CalculateArcSteps(halfThickness, 0, Mathf.PI, tessellateOptions);
for (int i = 1; i < arcSegments; i++)
{
float angle = Mathf.PI * (i / (float)arcSegments);
verts.Add(pos + Matrix2D.RotateLH(angle) * nrm * halfThickness * arcSign);
}
if (atStart)
{
// Note how we maintain the last two vertices being setup for connection by the rest of the path vertices
int indexTipStart = verts.Count;
verts.Add(pos + nrm * halfThickness);
verts.Add(pos - nrm * halfThickness);
for (int i = 1; i < arcSegments; i++)
{
inds.Add((UInt16)(indexTipStart + 1));
inds.Add((UInt16)(indexStart + i - 1));
inds.Add((UInt16)(indexStart + i));
}
}
else
{
inds.Add((UInt16)(indexStart - 1));
inds.Add((UInt16)(indexStart - 2));
inds.Add((UInt16)(indexStart + 0));
for (int i = 1; i < arcSegments - 1; i++)
{
inds.Add((UInt16)(indexStart - 1));
inds.Add((UInt16)(indexStart + i - 1));
inds.Add((UInt16)(indexStart + i));
}
}
break;
default:
System.Diagnostics.Debug.Assert(false); // Joining has its own function
break;
}
}
