protected override Vector3 ToCorner(RoadSegmentEndPoint neighbor, bool atEnd)
{
var neighborNormal = GetNeighborNormal(neighbor, atEnd);
var toCornerDirection = neighbor.To switch
{
null => DirectionNormalNoZ, // if I have no neighbor, use my own normal
StraightRoadSegment _ => Vector3.Normalize(DirectionNormalNoZ + neighborNormal), // if my neighbor is also a straight road segment, meet in the middle
_ => neighborNormal, // otherwise use my unflexible neighbor's normal
};
// This shouldn't happen but sometimes does in broken maps (Heartland Shield for example).
if (toCornerDirection.LengthSquared() < 0.1f)
{
toCornerDirection = DirectionNormalNoZ;
}
// When two road segments meet in an angled curve, their meeting edge is tilted and thus longer than the width of the road
// -> divide by cosine
// For straight roads ending in a curve or crossing:
// -> the angles in the crossing texture may not well match the actual angles of the incoming roads
// (especially for X-crossings, since there's only one texture for 4-road crossings which assumes 90° everywhere)
// -> the meeting edge may become quite tilted and noticeably longer than road width,
// while the road shown in the texture of the crossing always has the fixed road width
// -> to avoid visible breaks between the road segment and the crossing texture, distort the edge so its tilted seam is 'roadwidth' long
var cosine = Vector3.Dot(DirectionNormalNoZ, toCornerDirection);
var toCornerLength = neighbor.To is StraightRoadSegment ? HalfHeight / cosine : HalfHeight;
return(toCornerDirection * toCornerLength);
}
protected override Vector3 ToCorner(RoadSegmentEndPoint neighbor, bool atEnd)
{
var neighborNormal = GetNeighborNormal(neighbor, atEnd);
var segment = (StraightRoadSegment)Segment;
var oppositeNeighbor = atEnd ? segment.Start.To : segment.End.To;
var toCornerDirection = neighbor.To switch
{
null when oppositeNeighbor is CrossingRoadSegment crossing => // special handling to reproduce (somewhat strange) behavior of the original engine
OriginalNormal(crossing.Position),
null => // if I have no neighbor, use my own normal
DirectionNormalNoZ,
StraightRoadSegment _ => // if my neighbor is also a straight road segment, meet in the middle
Vector3.Normalize(DirectionNormalNoZ + neighborNormal),
_ => neighborNormal, // otherwise use my unflexible neighbor's normal
};
Vector3 OriginalNormal(Vector3 crossingPosition)
{
var originalDirection = atEnd ?
segment.EndPosition - crossingPosition :
crossingPosition - segment.StartPosition;
var originalDirectionNoZ = Vector3.Normalize(originalDirection.WithZ(0));
return(Vector3.Cross(originalDirectionNoZ, Vector3.UnitZ));
}
// This shouldn't happen but sometimes does in broken maps (Heartland Shield for example).
var toCornerLengthSquared = toCornerDirection.LengthSquared();
if (float.IsNaN(toCornerLengthSquared) || toCornerLengthSquared < 0.1f)
{
toCornerDirection = DirectionNormalNoZ;
}
// When two road segments meet in an angled curve, their meeting edge is tilted and thus longer than the width of the road
// -> divide by cosine
// For straight roads ending in a curve or crossing:
// -> the angles in the crossing texture may not well match the actual angles of the incoming roads
// (especially for X-crossings, since there's only one texture for 4-road crossings which assumes 90° everywhere)
// -> the meeting edge may become quite tilted and noticeably longer than road width,
// while the road shown in the texture of the crossing always has the fixed road width
// -> to avoid visible breaks between the road segment and the crossing texture, distort the edge so its tilted seam is 'roadwidth' long
var cosine = Vector3.Dot(DirectionNormalNoZ, toCornerDirection);
var toCornerLength = neighbor.To is StraightRoadSegment ? HalfHeight / cosine : HalfHeight;
return(toCornerDirection * toCornerLength);
}
private static IncomingRoadData GetIncomingRoadData(RoadTopologyNode node, RoadTopologyEdge incomingEdge, StraightRoadSegment edgeSegment)
{
var isStart = incomingEdge.Start.Position == node.Position;
var fromPosition = isStart ? edgeSegment.EndPosition : edgeSegment.StartPosition;
var segmentVector = (edgeSegment.EndPosition - edgeSegment.StartPosition) * (isStart ? 1 : -1);
var direction = segmentVector.LengthSquared() < 0.01f ? Vector3.UnitX : Vector3.Normalize(segmentVector);
return(new IncomingRoadData(
incomingEdge,
fromPosition,
direction,
MathF.Atan2(direction.Y, direction.X)));
}