mapbox-gl
Version:
A WebGL interactive maps library
177 lines (156 loc) • 6.56 kB
JavaScript
'use strict';
var util = require('../util/util');
var TileCoord = require('./tile_coord');
var LngLat = require('../geo/lng_lat');
var Point = require('point-geometry');
var Evented = require('../util/evented');
var ajax = require('../util/ajax');
var EXTENT = require('../data/bucket').EXTENT;
var RasterBoundsArray = require('../render/draw_raster').RasterBoundsArray;
var Buffer = require('../data/buffer');
var VertexArrayObject = require('../render/vertex_array_object');
module.exports = ImageSource;
/**
* A data source containing an image.
* (See the [Style Specification](https://www.mapbox.com/mapbox-gl-style-spec/#sources-image) for detailed documentation of options.)
*
* @interface ImageSource
* @example
* // add to map
* map.addSource('some id', {
* type: 'image',
* url: 'https://www.mapbox.com/images/foo.png',
* coordinates: [
* [-76.54, 39.18],
* [-76.52, 39.18],
* [-76.52, 39.17],
* [-76.54, 39.17]
* ]
* });
*
* // update
* var mySource = map.getSource('some id');
* mySource.setCoordinates([
* [-76.54335737228394, 39.18579907229748],
* [-76.52803659439087, 39.1838364847587],
* [-76.5295386314392, 39.17683392507606],
* [-76.54520273208618, 39.17876344106642]
* ]);
*
* map.removeSource('some id'); // remove
* @see [Add an image](https://www.mapbox.com/mapbox-gl-js/example/image-on-a-map/)
*/
function ImageSource(id, options, dispatcher, eventedParent) {
this.id = id;
this.dispatcher = dispatcher;
this.url = options.url;
this.coordinates = options.coordinates;
this.setEventedParent(eventedParent);
this.fire('dataloading', {dataType: 'source'});
ajax.getImage(options.url, function(err, image) {
if (err) return this.fire('error', {error: err});
this.image = image;
this._loaded = true;
this.fire('data', {dataType: 'source'});
this.fire('source.load');
if (this.map) {
this.setCoordinates(options.coordinates);
}
}.bind(this));
}
ImageSource.prototype = util.inherit(Evented, /** @lends ImageSource.prototype */ {
minzoom: 0,
maxzoom: 22,
tileSize: 512,
onAdd: function(map) {
this.map = map;
if (this.image) {
this.setCoordinates(this.coordinates);
}
},
/**
* Sets the image's coordinates and re-renders the map.
*
* @param {Array<Array<number>>} coordinates Four geographical coordinates,
* represented as arrays of longitude and latitude numbers, which define the corners of the image.
* The coordinates start at the top left corner of the image and proceed in clockwise order.
* They do not have to represent a rectangle.
* @returns {ImageSource} this
*/
setCoordinates: function(coordinates) {
this.coordinates = coordinates;
// Calculate which mercator tile is suitable for rendering the video in
// and create a buffer with the corner coordinates. These coordinates
// may be outside the tile, because raster tiles aren't clipped when rendering.
var map = this.map;
var cornerZ0Coords = coordinates.map(function(coord) {
return map.transform.locationCoordinate(LngLat.convert(coord)).zoomTo(0);
});
var centerCoord = this.centerCoord = util.getCoordinatesCenter(cornerZ0Coords);
centerCoord.column = Math.round(centerCoord.column);
centerCoord.row = Math.round(centerCoord.row);
this.minzoom = this.maxzoom = centerCoord.zoom;
this.coord = new TileCoord(centerCoord.zoom, centerCoord.column, centerCoord.row);
this._tileCoords = cornerZ0Coords.map(function(coord) {
var zoomedCoord = coord.zoomTo(centerCoord.zoom);
return new Point(
Math.round((zoomedCoord.column - centerCoord.column) * EXTENT),
Math.round((zoomedCoord.row - centerCoord.row) * EXTENT));
});
this.fire('data', {dataType: 'source'});
return this;
},
_setTile: function (tile) {
this._prepared = false;
this.tile = tile;
var maxInt16 = 32767;
var array = new RasterBoundsArray();
array.emplaceBack(this._tileCoords[0].x, this._tileCoords[0].y, 0, 0);
array.emplaceBack(this._tileCoords[1].x, this._tileCoords[1].y, maxInt16, 0);
array.emplaceBack(this._tileCoords[3].x, this._tileCoords[3].y, 0, maxInt16);
array.emplaceBack(this._tileCoords[2].x, this._tileCoords[2].y, maxInt16, maxInt16);
this.tile.buckets = {};
this.tile.boundsBuffer = new Buffer(array.serialize(), RasterBoundsArray.serialize(), Buffer.BufferType.VERTEX);
this.tile.boundsVAO = new VertexArrayObject();
this.tile.state = 'loaded';
},
prepare: function() {
if (!this.tile || !this._loaded || !this.image || !this.image.complete) return;
this._prepareImage(this.map.painter.gl, this.image);
},
_prepareImage: function (gl, image) {
if (!this._prepared) {
this._prepared = true;
this.tile.texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.tile.texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
} else {
gl.bindTexture(gl.TEXTURE_2D, this.tile.texture);
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, image);
}
},
loadTile: function(tile, callback) {
// We have a single tile -- whoose coordinates are this.coord -- that
// covers the image we want to render. If that's the one being
// requested, set it up with the image; otherwise, mark the tile as
// `errored` to indicate that we have no data for it.
if (this.coord && this.coord.toString() === tile.coord.toString()) {
this._setTile(tile);
callback(null);
} else {
tile.state = 'errored';
callback(null);
}
},
serialize: function() {
return {
type: 'image',
urls: this.url,
coordinates: this.coordinates
};
}
});