private static Vector3?Intersects(Ray3 ray, BuildingWallSegment wallSegment)
{
var height = ray.Point.Y;
if (height < wallSegment.Basement.Point1.Y ||
height > wallSegment.Basement.Point1.Y + wallSegment.Height)
{
return(null);
}
var ray2D = new Ray2(ray.Point.Xz, ray.Direction.Xz.Normalize());
var wallSeg2D = new LineSegment2(wallSegment.Basement.Point1.Xz, wallSegment.Basement.Point2.Xz);
var inter2D = wallSeg2D.Intersect(ray2D);
if (!inter2D.HasValue)
{
return(null);
}
return(new Vector3(inter2D.Value.X, ray.Point.Y, inter2D.Value.Y));
}
private static void GetExternalPart(LineSegment3 segment, BuildingPrimitive primitive, List <LineSegment3> results)
{
var invTransform = primitive.Transform.Invert();
var transformedSeg = new LineSegment3(segment.Point1 * invTransform, segment.Point2 * invTransform);
var seg = new LineSegment2(transformedSeg.Point1.Xz, transformedSeg.Point2.Xz);
if (primitive.Type == BuildingPrimitiveType.Rectangle)
{
var rect = new AaRectangle2(Vector2.Zero, primitive.Scale.X, primitive.Scale.Z);
var conains1 = rect.ContainsPoint(seg.Point1);
var conains2 = rect.ContainsPoint(seg.Point2);
if (conains1 && conains2)
{
return;
}
if (!conains1 && !conains2)
{
var p = Vector2.Zero;
int c = 0;
foreach (var rectSegment in rect.GetSegments())
{
var rsi = rectSegment.Intersect(seg);
if (rsi.HasValue)
{
p += rsi.Value;
c++;
}
}
if (c > 0)
{
var t = ((p / c) - seg.Point1).Length() / (seg.Point2 - seg.Point1).Length();
var m = segment.Point1 + (segment.Point2 - segment.Point1) * t;
GetExternalPart(new LineSegment3(segment.Point1, m), primitive, results);
GetExternalPart(new LineSegment3(m, segment.Point2), primitive, results);
return;
}
results.Add(segment);
return;
}
var swap = conains1;
if (swap)
{
CodingHelper.Swap(ref seg.Point1, ref seg.Point2);
}
var inter = seg.Intersect(new LineSegment2(
new Vector2(-primitive.Scale.X, -primitive.Scale.Z),
new Vector2(-primitive.Scale.X, primitive.Scale.Z)));
if (inter.HasValue)
{
var rs1 = To3(seg.Point1, inter.Value, primitive.Transform, swap);
results.Add(rs1);
return;
}
inter = seg.Intersect(new LineSegment2(
new Vector2(primitive.Scale.X, -primitive.Scale.Z),
new Vector2(primitive.Scale.X, primitive.Scale.Z)));
if (inter.HasValue)
{
var rs1 = To3(seg.Point1, inter.Value, primitive.Transform, swap);
results.Add(rs1);
return;
}
inter = seg.Intersect(new LineSegment2(
new Vector2(-primitive.Scale.X, primitive.Scale.Z),
new Vector2(primitive.Scale.X, primitive.Scale.Z)));
if (inter.HasValue)
{
var rs1 = To3(seg.Point1, inter.Value, primitive.Transform, swap);
results.Add(rs1);
return;
}
inter = seg.Intersect(new LineSegment2(
new Vector2(-primitive.Scale.X, -primitive.Scale.Z),
new Vector2(primitive.Scale.X, -primitive.Scale.Z)));
if (inter.HasValue)
{
var rs1 = To3(seg.Point1, inter.Value, primitive.Transform, swap);
results.Add(rs1);
return;
}
var rs2 = segment;
results.Add(rs2);
return;
}
else
{
var circle = new Circle2(Vector2.Zero, primitive.Scale.X);
var conains1 = circle.Contains(seg.Point1);
var conains2 = circle.Contains(seg.Point2);
if (conains1 && conains2)
{
return;
}
if (!conains1 && !conains2)
{
var rs1 = segment;
results.Add(rs1);
return;
}
var swap = conains1;
if (swap)
{
CodingHelper.Swap(ref seg.Point1, ref seg.Point2);
}
var dpp = seg.Point2 - seg.Point1;
var dpc = seg.Point1;
var a = dpp.LengthSquared();
var b = Vector2.Dot(dpp, dpc);
var c = dpc.LengthSquared() - circle.Radius.Sq();
var discr = b * b - a * c;
if (discr < 0)
{
results.Add(segment);
return;
}
if (discr < MathHelper.Eps5)
{
results.Add(segment);
return;
//var l = -b / a;
//if (0 <= l && l <= 1)
}
{
var sqrdscr = MathHelper.Sqrt(discr);
var l1 = (-b + sqrdscr) / a;
var l2 = (-b - sqrdscr) / a;
if (0 <= l1 && l1 <= 1)
{
var rs1 = To3(seg.Point1, Vector2.Lerp(seg.Point1, seg.Point2, l1), primitive.Transform, swap);
results.Add(rs1);
}
if (0 <= l2 && l2 <= 1)
{
var rs1 = To3(seg.Point1, Vector2.Lerp(seg.Point1, seg.Point2, l2), primitive.Transform, swap);
results.Add(rs1);
}
}
}
}