source-terrain.yaml

sources:
    mapzen:
        type: MVT
        url: https://tile.nextzen.org/tilezen/vector/v1/512/all/{z}/{x}/{y}.mvt
        tile_size: 512
        max_zoom: 16
        rasters: [normals]
        scripts: ['https://api.tiles.mapbox.com/mapbox.js/plugins/turf/v2.0.0/turf.min.js']
        transform: |
            function(data, extra_data) {
                var points = [];
                
                if (data.earth &&
                    data.earth.features) {
                    var earth_points = turf.explode(data.earth);
                    points = points.concat(earth_points.features);
                    
                    //var units = 'miles';
                    //var cellWidth = .1;
                    
                    //var buffed = turf.buffer(earth_points, cellWidth*.5, units)
                    //var bbox = turf.extent(buffed);
                    //var grid = turf.pointGrid(bbox, cellWidth, units);
                    //points = points.concat(grid.features);
                    
                    if (data.roads && data.roads.features) {
                        var roads_points = turf.explode(data.roads);
                        points = points.concat(roads_points.features);
                    }
                    if (data.landuse && data.landuse.features) {
                        var landuse_points = turf.explode(data.landuse);
                        points = points.concat(landuse_points.features);
                    }
                    if (data.buildings && data.buildings.features) {
                        var buildings_points = turf.explode(data.buildings);
                        points = points.concat(buildings_points.features);
                    }
                    if (data.water && data.water.features) {
                        var water_points = turf.explode(data.water);
                        points = points.concat(water_points.features);
                    }
                } else if (data.water && data.water.features) {
                    var water_points = turf.explode(data.water);
                    points = points.concat(water_points.features);
                }
                
                if (!data.terrain) {
                    data.terrain = {};
                    data.terrain = turf.tin(turf.featurecollection(points));
                }
                
                return data;
            }
    normals:
        type: Raster
        url: https://tile.nextzen.org/tilezen/terrain/v1/512/normal/{z}/{x}/{y}.png
        max_zoom: 14
        tile_size: 512
        url_params:
            api_key: NaqqS33fTUmyQcvbuIUCKA