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Display buildings in 3DExtrude polygons for 3D indoor mappingAdd a 3D modelAdjust a layer's opacityAnimate a lineAnimate a series of imagesAnimate a pointChange building color based on zoom levelChange the case of labelsDisplay HTML clusters with custom propertiesCreate and style clustersChange a layer's color with buttonsAdd a custom style layerStyle circles with a data-driven propertyStyle lines with a data-driven propertyDisplay and style rich text labelsAdd a pattern to a polygonAdd a new layer below labelsAdd a GeoJSON lineDraw GeoJSON pointsAdd a GeoJSON polygonCreate a heatmap layerCreate a gradient line using an expressionAdd multiple geometries from one GeoJSON sourceStyle ocean depth dataShow and hide layersChange worldview of administrative boundariesUpdate a choropleth layer by zoom levelVariable label placementVisualize population densityAdd hillshading

Generate and add a missing icon to the map

Dynamically generate a missing icon at runtime and add it to the map.

<!DOCTYPE html>
<html>
<head>
<meta charset='utf-8' />
<title>Generate and add a missing icon to the map</title>
<meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
<script src='https://api.tiles.mapbox.com/mapbox-gl-js/v1.2.1/mapbox-gl.js'></script>
<link href='https://api.tiles.mapbox.com/mapbox-gl-js/v1.2.1/mapbox-gl.css' rel='stylesheet' />
<style>
body { margin:0; padding:0; }
#map { position:absolute; top:0; bottom:0; width:100%; }
</style>
</head>
<body>
<div id='map'></div>
<script>
mapboxgl.accessToken = '<your access token here>';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/streets-v9'
});
map.on('styleimagemissing', function(e) {
var id = e.id; // id of the missing image
// check if this missing icon is one this function can generate
var prefix = 'square-rgb-';
if (id.indexOf(prefix) !== 0) return;
// extract the color from the id
var rgb = id.replace(prefix, '').split(',').map(Number);
var width = 64; // The image will be 64 pixels square
var bytesPerPixel = 4; // Each pixel is represented by 4 bytes: red, green, blue, and alpha.
var data = new Uint8Array(width * width * bytesPerPixel);
for (var x = 0; x < width; x++) {
for (var y = 0; y < width; y++) {
var offset = (y * width + x) * bytesPerPixel;
data[offset + 0] = rgb[0]; // red
data[offset + 1] = rgb[1]; // green
data[offset + 2] = rgb[2]; // blue
data[offset + 3] = 255; // alpha
}
}
map.addImage(id, {width: width, height: width, data: data});
});
map.on('load', function () {
map.addLayer({
"id": "points",
"type": "symbol",
"source": {
"type": "geojson",
"data": {
"type": "FeatureCollection",
"features": [{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [0, 0]
},
"properties": {
"color": "255,0,0"
}
}, {
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [50, 0]
},
"properties": {
"color": "255,209,28"
}
}, {
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [-50, 0]
},
"properties": {
"color": "242,127,32"
}
}]
}
},
"layout": {
"icon-image": ["concat", "square-rgb-", ["get", "color"]]
}
});
});
</script>
</body>
</html>
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