private static bool IsLineVisible(LineHL line, double nearPlaneDistance, TriangleHL[] triangles)
{
var rayAxis = GetRaytracingRay(line, nearPlaneDistance);
var(success, edgeIntersection) = GetRayIntersectionWithEdge(rayAxis, line.Edge);
if (!success)
{
return(true);
}
var rayToEdgeDirection = (edgeIntersection - rayAxis.Offset);
var edgeDistanceSquared = rayToEdgeDirection.SquaredLength();
foreach (var triangle in triangles)
{
if (!IsTriangleNeighbourOfLine(triangle, line))
{
if (!IsLineInTrianglePlane(line, triangle))
{
var(hasIntersection, triangleDistanceSquared) = IntersectionMath.GetSquaredDistanceOfIntersectionOfRayAndTriangle(rayAxis.Offset, rayToEdgeDirection, triangle.P1, triangle.P2, triangle.P3);
if (hasIntersection && triangleDistanceSquared < edgeDistanceSquared)
{
return(false);
}
}
}
}
return(true);
}
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 bool IsTriangleNeighbourOfLine(TriangleHL triangle, LineHL line)
{
var firstTriangle = line.Edge.First;
var secondTriangle = line.Edge.Second;
var isNeighbour = firstTriangle == triangle || secondTriangle == triangle;
return(isNeighbour);
}
private static bool IsLineInTrianglePlane(LineHL line, TriangleHL triangle)
{
var start = line.Edge.Start;
var end = line.Edge.End;
var distStart = start.DistancePositionToPlane(triangle.P1, triangle.Normal);
var distEnd = end.DistancePositionToPlane(triangle.P1, triangle.Normal);
var isInPlane = distStart.EqualsTo(0.0) && distEnd.EqualsTo(0.0);
return(isInPlane);
}
private static LineHL ToLine2D(this EdgeHL edge, double nearPlaneDist)
{
var(x1, y1) = ViewProjection.ProjectCameraSystemToCameraPlane(edge.Start, nearPlaneDist);
var(x2, y2) = ViewProjection.ProjectCameraSystemToCameraPlane(edge.End, nearPlaneDist);
var line2d = new LineHL {
Start = new PointHL(x1, y1), End = new PointHL(x2, y2), Edge = edge
};
return(line2d);
}
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 <int> ToLineCoordinates(this LineHL line, double canvasWidth, double canvasHeight)
{
var(x1, y1) = ViewProjection.ProjectCameraPlaneToCanvas(line.Start.X, line.Start.Y, canvasWidth, canvasHeight);
var(x2, y2) = ViewProjection.ProjectCameraPlaneToCanvas(line.End.X, line.End.Y, canvasWidth, canvasHeight);
yield return(x1);
yield return(y1);
yield return(x2);
yield return(y2);
}
private static bool IsLineVisible(LineHL line) => line.Edge.First.Spin == TriangleSpin.counter_clockwise || line.Edge.Second.Spin == TriangleSpin.counter_clockwise;
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);
}
