@deck.gl/experimental-layers
Version:
Experimental layers for deck.gl
107 lines (85 loc) • 4.09 kB
JavaScript
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.getTileIndices = getTileIndices;
var _viewportMercatorProject = require("viewport-mercator-project");
function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _nonIterableRest(); }
function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance"); }
function _iterableToArrayLimit(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }
function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }
function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
var TILE_SIZE = 512;
function getBoundingBox(viewport) {
var corners = [viewport.unproject([0, 0]), viewport.unproject([viewport.width, 0]), viewport.unproject([0, viewport.height]), viewport.unproject([viewport.width, viewport.height])];
return [corners.reduce(function (minLng, p) {
return minLng < p[0] ? minLng : p[0];
}, 180), corners.reduce(function (minLat, p) {
return minLat < p[1] ? minLat : p[1];
}, 90), corners.reduce(function (maxLng, p) {
return maxLng > p[0] ? maxLng : p[0];
}, -180), corners.reduce(function (maxLat, p) {
return maxLat > p[1] ? maxLat : p[1];
}, -90)];
}
function pixelsToTileIndex(a) {
return Math.floor(a / TILE_SIZE);
}
/**
* Returns all tile indices in the current viewport. If the current zoom level is smaller
* than minZoom, return an empty array. If the current zoom level is greater than maxZoom,
* return tiles that are on maxZoom.
*/
function getTileIndices(viewport, maxZoom, minZoom) {
var z = Math.floor(viewport.zoom);
if (minZoom && z < minZoom) {
return [];
}
viewport = new viewport.constructor(_objectSpread({}, viewport, {
zoom: z
}));
var bbox = getBoundingBox(viewport);
var _lngLatToWorld$map = (0, _viewportMercatorProject.lngLatToWorld)([bbox[0], bbox[3]], viewport.scale).map(pixelsToTileIndex),
_lngLatToWorld$map2 = _slicedToArray(_lngLatToWorld$map, 2),
minX = _lngLatToWorld$map2[0],
minY = _lngLatToWorld$map2[1];
var _lngLatToWorld$map3 = (0, _viewportMercatorProject.lngLatToWorld)([bbox[2], bbox[1]], viewport.scale).map(pixelsToTileIndex),
_lngLatToWorld$map4 = _slicedToArray(_lngLatToWorld$map3, 2),
maxX = _lngLatToWorld$map4[0],
maxY = _lngLatToWorld$map4[1];
var indices = [];
for (var x = minX; x <= maxX; x++) {
for (var y = minY; y <= maxY; y++) {
if (maxZoom && z > maxZoom) {
indices.push(getAdjustedTileIndex({
x: x,
y: y,
z: z
}, maxZoom));
} else {
indices.push({
x: x,
y: y,
z: z
});
}
}
}
return indices;
}
/**
* Calculates and returns a new tile index {x, y, z}, with z being the given adjustedZ.
*/
function getAdjustedTileIndex(_ref, adjustedZ) {
var x = _ref.x,
y = _ref.y,
z = _ref.z;
var m = Math.pow(2, z - adjustedZ);
return {
x: Math.floor(x / m),
y: Math.floor(y / m),
z: adjustedZ
};
}
//# sourceMappingURL=viewport-util.js.map
;