kopia lustrzana https://github.com/rastapasta/mapscii
134 wiersze
3.9 KiB
JavaScript
134 wiersze
3.9 KiB
JavaScript
/*
|
|
termap - Terminal Map Viewer
|
|
by Michael Strassburger <codepoet@cpan.org>
|
|
|
|
Minimalistic parser and compiler for Mapbox (Studio) Map Style files
|
|
See: https://www.mapbox.com/mapbox-gl-style-spec/
|
|
|
|
Compiles layer filter instructions into a chain of true/false returning
|
|
anonymous functions to improve rendering speed compared to realtime parsing.
|
|
*/
|
|
'use strict';
|
|
|
|
class Styler {
|
|
constructor(style) {
|
|
this.styleById = {};
|
|
this.styleByLayer = {};
|
|
var base, name;
|
|
this.styleName = style.name;
|
|
if (style.constants) {
|
|
this._replaceConstants(style.constants, style.layers);
|
|
}
|
|
|
|
for (const layer of style.layers) {
|
|
if (layer.ref && this.styleById[layer.ref]) {
|
|
for (const ref of ['type', 'source-layer', 'minzoom', 'maxzoom', 'filter']) {
|
|
if (this.styleById[layer.ref][ref] && !layer[ref]) {
|
|
layer[ref] = this.styleById[layer.ref][ref];
|
|
}
|
|
}
|
|
}
|
|
|
|
layer.appliesTo = this._compileFilter(layer.filter);
|
|
|
|
//TODO Better translation of: @styleByLayer[style['source-layer']] ?= []
|
|
if ((base = this.styleByLayer)[name = layer['source-layer']] == null) {
|
|
base[name] = [];
|
|
}
|
|
this.styleByLayer[layer['source-layer']].push(layer);
|
|
this.styleById[layer.id] = layer;
|
|
}
|
|
}
|
|
|
|
getStyleFor(layer, feature) {
|
|
if (!this.styleByLayer[layer]) {
|
|
return false;
|
|
}
|
|
|
|
for (const style of this.styleByLayer[layer]) {
|
|
if (style.appliesTo(feature)) {
|
|
return style;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
_replaceConstants(constants, tree) {
|
|
for (const id in tree) {
|
|
const node = tree[id];
|
|
switch (typeof node) {
|
|
case 'object':
|
|
if (node.constructor.name.match(/Stream/)) {
|
|
continue;
|
|
}
|
|
this._replaceConstants(constants, node);
|
|
break;
|
|
case 'string':
|
|
if (node.charAt(0) === '@') {
|
|
tree[id] = constants[node];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//TODO Better translation of the long cases.
|
|
_compileFilter(filter) {
|
|
let filters;
|
|
switch (filter != null ? filter[0] : void 0) {
|
|
case 'all':
|
|
filter = filter.slice(1);
|
|
filters = (() => {
|
|
return filter.map((sub) => this._compileFilter(sub));
|
|
}).call(this);
|
|
return (feature) => !!filters.find((appliesTo) => {
|
|
return !appliesTo(feature);
|
|
});
|
|
case 'any':
|
|
filter = filter.slice(1);
|
|
filters = (() => {
|
|
return filter.map((sub) => this._compileFilter(sub));
|
|
}).call(this);
|
|
return (feature) => !!filters.find((appliesTo) => {
|
|
return appliesTo(feature);
|
|
});
|
|
case 'none':
|
|
filter = filter.slice(1);
|
|
filters = (() => {
|
|
return filter.map((sub) => this._compileFilter(sub));
|
|
}).call(this);
|
|
return (feature) => !filters.find((appliesTo) => {
|
|
return !appliesTo(feature);
|
|
});
|
|
case '==':
|
|
return (feature) => feature.properties[filter[1]] === filter[2];
|
|
case '!=':
|
|
return (feature) => feature.properties[filter[1]] !== filter[2];
|
|
case 'in':
|
|
return (feature) => !!filter.slice(2).find((value) => {
|
|
return feature.properties[filter[1]] === value;
|
|
});
|
|
case '!in':
|
|
return (feature) => !filter.slice(2).find((value) => {
|
|
return feature.properties[filter[1]] === value;
|
|
});
|
|
case 'has':
|
|
return (feature) => !!feature.properties[filter[1]];
|
|
case '!has':
|
|
return (feature) => !feature.properties[filter[1]];
|
|
case '>':
|
|
return (feature) => feature.properties[filter[1]] > filter[2];
|
|
case '>=':
|
|
return (feature) => feature.properties[filter[1]] >= filter[2];
|
|
case '<':
|
|
return (feature) => feature.properties[filter[1]] < filter[2];
|
|
case '<=':
|
|
return (feature) => feature.properties[filter[1]] <= filter[2];
|
|
default:
|
|
return () => true;
|
|
}
|
|
}
|
|
}
|
|
|
|
module.exports = Styler;
|