Leaflet.Canvas-Markers

Leaflet plugin for displaying markers on canvas instead of DOM. Working with Leaflet 1.0.0 and above. Feel free to contribute.

This fork contains a fix for zoom animations, which came from a branch of Oleg Podchashynskyi's (corg) fork https://github.com/corg/Leaflet.Canvas-Markers In addition, it adds a setEnforceZIndex() function that can be used to support maintaining the marker zIndexOffset during rendering. As the markers returned by the Rbush search results were not being sorted by zIndexOffset.

Demo

There's a demo for 10000 points, running on Canvas

Installation and basic usage

Just download leaflet.canvas-markers.js from the dist folder and attach it to your project.

<script src="leaflet.canvas-markers.js"></script>

Now attach layer to map and some markers.

// Adds a layer
var ciLayer = L.canvasIconLayer({}).addTo(map);

// Marker definition
var marker =  L.marker([58.5578, 29.0087], {icon: icon});

// Adding marker to layer
ciLayer.addMarker(marker);

// Ensure zIndexOffset is respected during rendering.
ciLayer.setEnforceZIndex(true);

Benchmark

Plugin was tested in Google Chrome v66 & IE11. There is results for 100000 markers:

Parameter	Default Leaflet Markers	Leaflet.Canvas-Markers
Memory used	up to 2.8 Gb	about 300 Mb
First load time	160-200 seconds	<1 seconds
Zoom and move time	more than 3 minutes	0.5 seconds

As you can see DOM operations are slow, so you should use canvas for a large number of markers.

You can also use L.circleMarker for your points with similar performance, but then you're limited to icon design.

Methods

• addMarker(marker): Adds a marker to the layer.
• addMarkers(markers): Adds a markers to the layer.
• removeMarker(marker, redraw): Removes a marker from the layer. Set redraw to true if you want to redraw layer after marker remove
• redraw(): Redraws the layer
• addOnClickListener(eventHandler): Adds common click listener for all markers
• addOnHoverListener(eventHandler): Adds a hover over listener for all markers
• setEnforceZIndex(enforce): Markers will be rendered maintaining their zIndexOffset ordering.
• initializeCanvas: Sets the size and position of the canvas. Required to ensure all markers are rendered at the correct location if the map will be immediately moved/zoomed programmatically, or is manually moved before the first canvas redraw() occurs.

I also implemented binds for default addLayer, addLayers and removeLayer (equal to removeMarker(marker, true) methods.

Contributors

crzo, Spaction