Flutter_map: Getting screen position from latlng values

[aytunch]

I have several markers in the map and of course I know the LatLng values. However I want to know their coordinates in terms of screen dimensions.

Is there a method which returns a screen position in pixels(x,y) from latlng? Of course I assume current zoom factor must be taken into consideration.

If I there is a solution, I will use this info to implement marker clustering by checking how close are the markers in the actual screen.

[aytunch]

@RaimundWege I am sure you got this:) I know you worked on clustering before. Thanks and sorry for the mention if it is any inconvenience.

[RaimundWege]

@aytunch right now I prepare a marker layer for each supported zoom level and switch the layer when the zoom level did change. To decide if a marker is to close to another marker I calculate the map tile size for the current zoom level with:

double mapTileLength = 360 / pow(2, zoomLevel);

and then I calculate the min distance two marker should have with:

double minDistanceBetweenMarker = 8 * (mapTileLength / pow(2, zoomLevel));

The values are always in degree.

There are some assumptions but currently it fits my needs:

[aytunch]

@RaimundWege I will try to implement this solution asap. thanks for the detailed info and the beautiful gif:)

One thing I noticed in your gif while I checked the frames one by one is that your markers seems to stay in screen even when more than half of them is out of the screen. There is no unwanted disappearing effect. I opened up an issue here: Issue:230 When the anchor point is out of bounds, the whole marker widget disappears

Do you have a solution for that? Or I am deceived by the Gif?

[RaimundWege]

@aytunch the gif is missleading. The markers are still disappearing to early.

[guediagael]

Guys can you please share the solution? Like a gist please ? Any code snippet will be very useful. Thanks in advance

[lpongetti]

https://github.com/lpongetti/flutter_map_marker_cluster

[aytunch]

I found a solution:

CustomPoint<num> screenPosition =
            Epsg3857().latLngToPoint(mapPosition.center, mapPosition.zoom);

This should give you the center x,y for your screen so something like x:250, y:450 according to the device of course.