private static (bool, EdgeHL) ClippEdgeAtNearPlane(EdgeHL edge, double nearPlaneDist)
{
var start = edge.Start;
var end = edge.End;
if ((start.Y < nearPlaneDist) || (end.Y < nearPlaneDist))
{
if ((start.Y < nearPlaneDist) && (end.Y < nearPlaneDist))
{
return(false, null);
}
var direction = end - start;
var intersection = start;
if (direction.Y != 0.0)
{
double lamda = Math.Abs((start.Y - nearPlaneDist) / direction.Y);
intersection += direction * lamda;
}
if (start.Y < nearPlaneDist)
{
start = intersection;
}
else
{
end = intersection;
}
}
return(true, new EdgeHL {
Start = start, End = end, First = edge.First, Second = edge.Second, Edge = edge.Edge
});
}
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 (bool, Position3D) GetRayIntersectionWithEdge(Axis3D rayAxis, EdgeHL edge)
{
var edgeEnd = edge.End;
var edgeOffset = edge.Start;
var edgeDirection = edgeEnd - edgeOffset;
var edgeAxis = new Axis3D(edgeOffset, edgeDirection);
var(success, intersection) = edgeAxis.CalculatePerpendicularPoint(rayAxis);
return(success, intersection);
}
private static EdgeHL ConvertToEdgeHL(Edge edge, Dictionary <Triangle, TriangleHL> dict, Matrix44D cameraAndBodyFrame)
{
var edgeHL = new EdgeHL()
{
Start = cameraAndBodyFrame * edge.Start.Position,
End = cameraAndBodyFrame * edge.End.Position,
First = dict.ContainsKey(edge.First.ParentTriangle) ? dict[edge.First.ParentTriangle] : null,
Second = dict.ContainsKey(edge.Second.ParentTriangle) ? dict[edge.Second.ParentTriangle] : null,
Edge = edge
};
return(edgeHL);
}
private static bool IsLineBorderEdge(EdgeHL edge)
{
var firstTriangle = edge.First;
var secondTriangle = edge.Second;
var isFirstTriangleVisible = IsTriangleVisible(firstTriangle);
var isSecondTriangleVisible = IsTriangleVisible(secondTriangle);
if (isFirstTriangleVisible != isSecondTriangleVisible)
{
return(true);
}
if (((firstTriangle.Face.HasBorder || secondTriangle.Face.HasBorder) && (firstTriangle.Face != secondTriangle.Face || firstTriangle == secondTriangle)) ||
(firstTriangle.Face.HasFacets || secondTriangle.Face.HasFacets))
{
return(true);
}
return(false);
}