public bool VertexOnLine(OECPVertex vtx, ref OECPVertex projVtx)
{
var lst = new List <OECPLayer>();
foreach (OECPLayer layer in Layers)
{
if (!layer.IsLine)
{
continue;
}
if (!layer.IsVisible)
{
continue;
}
lst.Add(layer);
}
return(CanvasUtil.VertexOnLine(vtx, lst, ref projVtx));
}