private static IEnumerable <LineHL> ClippAtBottom(this IEnumerable <LineHL> lines, double bottom)
{
foreach (var line in lines)
{
var start = line.Start;
var end = line.End;
if ((start.Y >= bottom) || (end.Y >= bottom))
{
if ((start.Y >= bottom) && (end.Y >= bottom))
{
yield return(line);
}
else
{
if (start.Y > end.Y)
{
var help = start;
start = end;
end = help;
}
double qy = (bottom - start.Y) / (end.Y - start.Y);
double deltax = qy * (end.X - start.X);
var clippedStart = new PointHL(start.X + deltax, bottom);
yield return(new LineHL {
Start = clippedStart, End = end, Edge = line.Edge
});
}
}
}
}
private static (bool, LineHL) ClippAtLeft(this LineHL line, double left)
{
var start = line.Start;
var end = line.End;
if ((start.X < left) && (end.X < left))
{
return(false, null);
}
if ((start.X >= left) && (end.X >= left))
{
return(true, line);
}
else
{
if (start.X > end.X)
{
var help = start;
start = end;
end = help;
}
double qx = (left - start.X) / (end.X - start.X);
double deltay = qx * (end.Y - start.Y);
var clippedStart = new PointHL(left, start.Y + deltay);
return(true, new LineHL {
Start = clippedStart, End = end, Edge = line.Edge
});
}
}
private static IEnumerable <LineHL> ClippAtRight(this IEnumerable <LineHL> lines, double right)
{
foreach (var line in lines)
{
var start = line.Start;
var end = line.End;
if ((start.X <= right) || (end.X <= right))
{
if ((start.X <= right) && (end.X <= right))
{
yield return(line);
}
else
{
if (start.X > end.X)
{
var help = start;
start = end;
end = help;
}
double qx = (right - start.X) / (end.X - start.X);
double deltay = qx * (end.Y - start.Y);
var clippedEnd = new PointHL(right, start.Y + deltay);
yield return(new LineHL {
Start = start, End = clippedEnd, Edge = line.Edge
});
}
}
}
}
private static Axis3D GetRaytracingRay(LineHL line, double nearPlaneDistance)
{
var start = line.Start;
var end = line.End;
var centerViewLine = new PointHL((start.X + end.X) / 2.0, (start.Y + end.Y) / 2.0);
var centerCameraPlaneLine = ViewProjection.ProjectCameraPlaneToCameraSystem(centerViewLine.X, centerViewLine.Y, nearPlaneDistance);
var rayOffset = new Position3D(0.0, 0.0, 0.0);
var rayDirection = centerCameraPlaneLine - rayOffset;
return(new Axis3D(rayOffset, rayDirection));
}
public static IEnumerable <LineHL> CutLines(this IEnumerable <LineHL> lines)
{
var source = new Stack <LineHL>(lines);
var target = new Stack <LineHL>();
var cutLines = new Stack <LineHL>();
while (source.Count > 0)
{
var first = source.Pop();
// Testcode
while (source.Count > 0)
{
var second = source.Pop();
var x1 = first.Start.X;
var y1 = first.Start.Y;
var x2 = first.End.X;
var y2 = first.End.Y;
var x3 = second.Start.X;
var y3 = second.Start.Y;
var x4 = second.End.X;
var y4 = second.End.Y;
if (IntersectionMath.AreLinesBoundedBoxesOverlapped(x1, y1, x2, y2, x3, y3, x4, y4))
{
var(hasIntersection, x, y) = IntersectionMath.Check2DLineWithLine(x1, y1, x2, y2, x3, y3, x4, y4);
if (hasIntersection)
{
var intersection = new PointHL(x, y);
var first1 = new LineHL {
Start = first.Start, End = intersection, Edge = first.Edge
};
var first2 = new LineHL {
Start = intersection, End = first.End, Edge = first.Edge
};
var second1 = new LineHL {
Start = second.Start, End = intersection, Edge = second.Edge
};
var second2 = new LineHL {
Start = intersection, End = second.End, Edge = second.Edge
};
if (!first2.Length.EqualsTo(0.0))
{
if (!first1.Length.EqualsTo(0.0))
{
target.Push(first2);
first = first1;
}
else
{
first = first2;
}
}
else
{
first = first1;
}
if (!second1.Length.EqualsTo(0.0))
{
target.Push(second1);
}
if (!second2.Length.EqualsTo(0.0))
{
target.Push(second2);
}
}
else
{
target.Push(second);
}
}
else
{
target.Push(second);
}
}
cutLines.Push(first);
var help = source;
source = target;
target = help;
}
return(cutLines);
}
