I'm working website which uses a lot of markers. And for performance reasons I'm going to render only visible markers after each move.
I'm using mapbox js library via react-mapbox-gl react library.
Any advice how to get visible coordinates from map? Top left and bottom right visible coordinates is enough.
You can use map.getBounds() or map.getBounds().toArray().
Related
When zooming into the map, do the tiles ever get unloaded? Or do they just stack on top of each other? For example - if I zoom in from zoom level 4 to zoom level 6, do the new set of tiles replace the old ones? Or do they simply cover them?
The reason I am asking is that I am loading a 3D terrain mesh on top of each tile that loads, but I have found that I am getting multiple terrains stacking on top of each other (refer to my aforementioned zoom level example).
Ideally I would like to simply unload the terrain cover whenever the corresponding tile unloads, but the mapbox-gl library does not seem to expose that event...
Any info on this subject would help me figure out a working solution. Thanks!
I'm starting research to add a user feature to an existing map built in Mapbox GL JS (wrapped in an Angular 2+ application). What I need to do, is allow a user to be able to draw and rotate ellipses and text labels over the top of a map, and be able to save screen captures of the result.
I'm coming into this with no experience in Mapbox or Leaflet, so I have a lot to figure out. My first goal is to determine if I can do this in Mapbox directly (with a plugin?), of if I will need to render a canvas over the top of my map with some third-part drawing library (I have a lot of experience with those).
The obvious advantage to doing this in Mapbox directly would be that we might still be able zoom and pan.
The Mapbox-gl-draw library lets the user author features in a map, but probably not to the extent you need.
If the features the user creates don't need to live "in map space" (ie, the map is static, and the labels are statically positioned over the top, for printing), working directly on a canvas will give you much more flexibility. You'll also have access to a much wider variety of libraries.
Using leaflet mobile maps, you can easily get "lost" if you zoom in too far or pan in the wrong direction, so I'd like to display some kind of dynamic hint arrows(?) around the edge of the map which point to those offscreen markers. Something like the illustration below which I stumbled on here while trying to find a solution.
You would probably be interested in Leaflet EdgeMarker plugin (demo):
[…] allows you to indicate Markers, Circles and CircleMarkers that are outside of the current view by displaying [a chosen icon (like an arrow)] at the edges of the map.
I try to repeat a marker at the same coordinates when I am moving the map to infinity, in the same way that layers.
example : https://www.mapbox.com/mapbox-gl-js/example/geojson-polygon/
Has anyone found how to do that please?
If it's not possible, conversely is it possible to not repeat layers when you moving the map ?
Thank you
The Link example you provided is not using Markers to render the shaded area. It is using a feature, in this case a polygon, included in a layer (a layer can have many features).
In MapBox the rendered map is made up of any number of layers (including the tile data) which is rendered whenever you scroll or drag to a particular area of the map. For example as you keep dragging to the right in the map it will just keep rendering in the relevant layers and tiles.
The Marker functionality has a different purpose which is as a one off selected point which is useful for a user click or hover interaction.
I want to use leaflet as Map library and use Cytoscape.js to display nodes as overlay. Also node locations are updated with zoom in and zoom out. What are the challenges on the way. Any suggestions?
I have list can anyone support :
Use canvas element as overlay on leaflet.
how to translate geo location to canvas location
relocating nodes on zoom in and zoom out.
What are the challenges on the way?
A lot. You'll have to be more specific when asking.
Use canvas element as overlay on leaflet.
See the documentation for L.Canvas (and its source code if you want to implement something similar).
how to translate geo location to canvas location relocating nodes on zoom in and zoom out.
See the L.Map.LatLngToContainerPoint() method. Zoom animations are handled via CSS and screen coordinates of map layers are not recalculated during zoom animation frames.