我与我的努力获得PointLatLng虚拟圆弧的名单GMAP-应用给出3点(中心,开始,结束)
使用GMAP.NET库,我想画一个充满弧由3个坐标给出的多边形:center_coordinate
,start_coordinate
和end_coordinate
(全部格式为DD,MM.MMM
)。
由于知道我想以适当的分辨率在地图上绘制圆弧作为多边形,我还额外定义了多个分段和顺时针/逆时针方向信息。
我通常知道如何绘制一个多边形(由列表PointLatLng
产生)到GMAP.NET地图上。这工作正常,所以我决定得到PointLatLng
列表。
我的问题是,我没有关于如何计算理想弧上每个点的具体想法。
我到目前为止已经
Public Function list_of_points_on_arc(point_center As PointLatLng, point_arc_start As PointLatLng, point_arc_end As PointLatLng, direction As String) As List(Of PointLatLng)
'direction: CW - clockwise/CC - Counter Clockwise
Const radiusEarthKilometres As Double = 6371.01
'sets the resolution of arc
Dim elements As Integer = 20
'unknown point on arc, each ...element
Dim point_on_arc As PointLatLng
'List collects all points aon arc
Dim gpollist As List(Of PointLatLng) = New List(Of PointLatLng)
For i As Integer = 0 To elements
' ?????????????????????????????????????????????????????????
'calculates new point_on_arc based on following information
' - elements, point_center, point_arc_start, point_arc_end
' ...
'
' ...
'
' point_on_arc = New PointLatLng(on_arc_lat, on_arc_lon)
' ?????????????????????????????????????????????????????????
'adds point_on_arc to list
gpollist.Add(point_on_arc)
Next
'returns list of pointsLatLon
Return gpollist
End Function
做任何有助于推动我在正确的方向是高度赞赏。谢谢。