helimap
Version:
map heliware
1,259 lines (1,141 loc) • 38.3 kB
JavaScript
/**
* @module ol/layer/Graticule
*/
import Collection from '../Collection.js';
import EventType from '../render/EventType.js';
import Feature from '../Feature.js';
import Fill from '../style/Fill.js';
import LineString from '../geom/LineString.js';
import Point from '../geom/Point.js';
import Stroke from '../style/Stroke.js';
import Style from '../style/Style.js';
import Text from '../style/Text.js';
import VectorLayer from './Vector.js';
import VectorSource from '../source/Vector.js';
import {
applyTransform,
approximatelyEquals,
containsCoordinate,
containsExtent,
equals,
getCenter,
getIntersection,
getWidth,
intersects,
isEmpty,
wrapX as wrapExtentX,
} from '../extent.js';
import {clamp} from '../math.js';
import {degreesToStringHDMS} from '../coordinate.js';
import {
equivalent as equivalentProjection,
get as getProjection,
getTransform,
} from '../proj.js';
import {getVectorContext} from '../render.js';
import {meridian, parallel} from '../geom/flat/geodesic.js';
/**
* @type {Stroke}
* @private
* @const
*/
const DEFAULT_STROKE_STYLE = new Stroke({
color: 'rgba(0,0,0,0.2)',
});
/**
* @type {Array<number>}
* @private
*/
const INTERVALS = [
90,
45,
30,
20,
10,
5,
2,
1,
30 / 60,
20 / 60,
10 / 60,
5 / 60,
2 / 60,
1 / 60,
30 / 3600,
20 / 3600,
10 / 3600,
5 / 3600,
2 / 3600,
1 / 3600,
];
/**
* @typedef {Object} GraticuleLabelDataType
* @property {Point} geom Geometry.
* @property {string} text Text.
*/
/**
* @typedef {Object} Options
* @property {string} [className='ol-layer'] A CSS class name to set to the layer element.
* @property {number} [opacity=1] Opacity (0, 1).
* @property {boolean} [visible=true] Visibility.
* @property {import("../extent.js").Extent} [extent] The bounding extent for layer rendering. The layer will not be
* rendered outside of this extent.
* @property {number} [zIndex] The z-index for layer rendering. At rendering time, the layers
* will be ordered, first by Z-index and then by position. When `undefined`, a `zIndex` of 0 is assumed
* for layers that are added to the map's `layers` collection, or `Infinity` when the layer's `setMap()`
* method was used.
* @property {number} [minResolution] The minimum resolution (inclusive) at which this layer will be
* visible.
* @property {number} [maxResolution] The maximum resolution (exclusive) below which this layer will
* be visible.
* @property {number} [minZoom] The minimum view zoom level (exclusive) above which this layer will be
* visible.
* @property {number} [maxZoom] The maximum view zoom level (inclusive) at which this layer will
* be visible.
* @property {number} [maxLines=100] The maximum number of meridians and
* parallels from the center of the map. The default value of 100 means that at
* most 200 meridians and 200 parallels will be displayed. The default value is
* appropriate for conformal projections like Spherical Mercator. If you
* increase the value, more lines will be drawn and the drawing performance will
* decrease.
* @property {Stroke} [strokeStyle] The
* stroke style to use for drawing the graticule. If not provided, the following stroke will be used:
* ```js
* new Stroke({
* color: 'rgba(0, 0, 0, 0.2)' // a not fully opaque black
* });
* ```
* @property {number} [targetSize=100] The target size of the graticule cells,
* in pixels.
* @property {boolean} [showLabels=false] Render a label with the respective
* latitude/longitude for each graticule line.
* @property {function(number):string} [lonLabelFormatter] Label formatter for
* longitudes. This function is called with the longitude as argument, and
* should return a formatted string representing the longitude. By default,
* labels are formatted as degrees, minutes, seconds and hemisphere.
* @property {function(number):string} [latLabelFormatter] Label formatter for
* latitudes. This function is called with the latitude as argument, and
* should return a formatted string representing the latitude. By default,
* labels are formatted as degrees, minutes, seconds and hemisphere.
* @property {number} [lonLabelPosition=0] Longitude label position in fractions
* (0..1) of view extent. 0 means at the bottom of the viewport, 1 means at the
* top.
* @property {number} [latLabelPosition=1] Latitude label position in fractions
* (0..1) of view extent. 0 means at the left of the viewport, 1 means at the
* right.
* @property {Text} [lonLabelStyle] Longitude label text
* style. If not provided, the following style will be used:
* ```js
* new Text({
* font: '12px Calibri,sans-serif',
* textBaseline: 'bottom',
* fill: new Fill({
* color: 'rgba(0,0,0,1)'
* }),
* stroke: new Stroke({
* color: 'rgba(255,255,255,1)',
* width: 3
* })
* });
* ```
* Note that the default's `textBaseline` configuration will not work well for
* `lonLabelPosition` configurations that position labels close to the top of
* the viewport.
* @property {Text} [latLabelStyle] Latitude label text style.
* If not provided, the following style will be used:
* ```js
* new Text({
* font: '12px Calibri,sans-serif',
* textAlign: 'end',
* fill: new Fill({
* color: 'rgba(0,0,0,1)'
* }),
* stroke: Stroke({
* color: 'rgba(255,255,255,1)',
* width: 3
* })
* });
* ```
* Note that the default's `textAlign` configuration will not work well for
* `latLabelPosition` configurations that position labels close to the left of
* the viewport.
* @property {Array<number>} [intervals=[90, 45, 30, 20, 10, 5, 2, 1, 30/60, 20/60, 10/60, 5/60, 2/60, 1/60, 30/3600, 20/3600, 10/3600, 5/3600, 2/3600, 1/3600]]
* Intervals (in degrees) for the graticule. Example to limit graticules to 30 and 10 degrees intervals:
* ```js
* [30, 10]
* ```
* @property {boolean} [wrapX=true] Whether to repeat the graticule horizontally.
* @property {Object<string, *>} [properties] Arbitrary observable properties. Can be accessed with `#get()` and `#set()`.
*/
/**
* @classdesc
* Layer that renders a grid for a coordinate system (currently only EPSG:4326 is supported).
* Note that the view projection must define both extent and worldExtent.
*
* @fires import("../render/Event.js").RenderEvent
* @extends {VectorLayer<import("../source/Vector.js").default>}
* @api
*/
class Graticule extends VectorLayer {
/**
* @param {Options} [options] Options.
*/
constructor(options) {
options = options ? options : {};
const baseOptions = Object.assign(
{
updateWhileAnimating: true,
updateWhileInteracting: true,
renderBuffer: 0,
},
options
);
delete baseOptions.maxLines;
delete baseOptions.strokeStyle;
delete baseOptions.targetSize;
delete baseOptions.showLabels;
delete baseOptions.lonLabelFormatter;
delete baseOptions.latLabelFormatter;
delete baseOptions.lonLabelPosition;
delete baseOptions.latLabelPosition;
delete baseOptions.lonLabelStyle;
delete baseOptions.latLabelStyle;
delete baseOptions.intervals;
super(baseOptions);
/**
* @type {import("../proj/Projection.js").default}
*/
this.projection_ = null;
/**
* @type {number}
* @private
*/
this.maxLat_ = Infinity;
/**
* @type {number}
* @private
*/
this.maxLon_ = Infinity;
/**
* @type {number}
* @private
*/
this.minLat_ = -Infinity;
/**
* @type {number}
* @private
*/
this.minLon_ = -Infinity;
/**
* @type {number}
* @private
*/
this.maxX_ = Infinity;
/**
* @type {number}
* @private
*/
this.maxY_ = Infinity;
/**
* @type {number}
* @private
*/
this.minX_ = -Infinity;
/**
* @type {number}
* @private
*/
this.minY_ = -Infinity;
/**
* @type {number}
* @private
*/
this.targetSize_ =
options.targetSize !== undefined ? options.targetSize : 100;
/**
* @type {number}
* @private
*/
this.maxLines_ = options.maxLines !== undefined ? options.maxLines : 100;
/**
* @type {Array<LineString>}
* @private
*/
this.meridians_ = [];
/**
* @type {Array<LineString>}
* @private
*/
this.parallels_ = [];
/**
* @type {Stroke}
* @private
*/
this.strokeStyle_ =
options.strokeStyle !== undefined
? options.strokeStyle
: DEFAULT_STROKE_STYLE;
/**
* @type {import("../proj.js").TransformFunction|undefined}
* @private
*/
this.fromLonLatTransform_ = undefined;
/**
* @type {import("../proj.js").TransformFunction|undefined}
* @private
*/
this.toLonLatTransform_ = undefined;
/**
* @type {import("../coordinate.js").Coordinate}
* @private
*/
this.projectionCenterLonLat_ = null;
/**
* @type {import("../coordinate.js").Coordinate}
* @private
*/
this.bottomLeft_ = null;
/**
* @type {import("../coordinate.js").Coordinate}
* @private
*/
this.bottomRight_ = null;
/**
* @type {import("../coordinate.js").Coordinate}
* @private
*/
this.topLeft_ = null;
/**
* @type {import("../coordinate.js").Coordinate}
* @private
*/
this.topRight_ = null;
/**
* @type {Array<GraticuleLabelDataType>}
* @private
*/
this.meridiansLabels_ = null;
/**
* @type {Array<GraticuleLabelDataType>}
* @private
*/
this.parallelsLabels_ = null;
if (options.showLabels) {
/**
* @type {null|function(number):string}
* @private
*/
this.lonLabelFormatter_ =
options.lonLabelFormatter == undefined
? degreesToStringHDMS.bind(this, 'EW')
: options.lonLabelFormatter;
/**
* @type {function(number):string}
* @private
*/
this.latLabelFormatter_ =
options.latLabelFormatter == undefined
? degreesToStringHDMS.bind(this, 'NS')
: options.latLabelFormatter;
/**
* Longitude label position in fractions (0..1) of view extent. 0 means
* bottom, 1 means top.
* @type {number}
* @private
*/
this.lonLabelPosition_ =
options.lonLabelPosition == undefined ? 0 : options.lonLabelPosition;
/**
* Latitude Label position in fractions (0..1) of view extent. 0 means left, 1
* means right.
* @type {number}
* @private
*/
this.latLabelPosition_ =
options.latLabelPosition == undefined ? 1 : options.latLabelPosition;
/**
* @type {Style}
* @private
*/
this.lonLabelStyleBase_ = new Style({
text:
options.lonLabelStyle !== undefined
? options.lonLabelStyle.clone()
: new Text({
font: '12px Calibri,sans-serif',
textBaseline: 'bottom',
fill: new Fill({
color: 'rgba(0,0,0,1)',
}),
stroke: new Stroke({
color: 'rgba(255,255,255,1)',
width: 3,
}),
}),
});
/**
* @private
* @param {import("../Feature").default} feature Feature
* @return {Style} style
*/
this.lonLabelStyle_ = (feature) => {
const label = feature.get('graticule_label');
this.lonLabelStyleBase_.getText().setText(label);
return this.lonLabelStyleBase_;
};
/**
* @type {Style}
* @private
*/
this.latLabelStyleBase_ = new Style({
text:
options.latLabelStyle !== undefined
? options.latLabelStyle.clone()
: new Text({
font: '12px Calibri,sans-serif',
textAlign: 'right',
fill: new Fill({
color: 'rgba(0,0,0,1)',
}),
stroke: new Stroke({
color: 'rgba(255,255,255,1)',
width: 3,
}),
}),
});
/**
* @private
* @param {import("../Feature").default} feature Feature
* @return {Style} style
*/
this.latLabelStyle_ = (feature) => {
const label = feature.get('graticule_label');
this.latLabelStyleBase_.getText().setText(label);
return this.latLabelStyleBase_;
};
this.meridiansLabels_ = [];
this.parallelsLabels_ = [];
this.addEventListener(EventType.POSTRENDER, this.drawLabels_.bind(this));
}
/**
* @type {Array<number>}
* @private
*/
this.intervals_ =
options.intervals !== undefined ? options.intervals : INTERVALS;
// use a source with a custom loader for lines & text
this.setSource(
new VectorSource({
loader: this.loaderFunction.bind(this),
strategy: this.strategyFunction.bind(this),
features: new Collection(),
overlaps: false,
useSpatialIndex: false,
wrapX: options.wrapX,
})
);
/**
* feature pool to use when updating graticule
* @type {Array<Feature>}
* @private
*/
this.featurePool_ = [];
/**
* @type {Style}
* @private
*/
this.lineStyle_ = new Style({
stroke: this.strokeStyle_,
});
/**
* @type {?import("../extent.js").Extent}
* @private
*/
this.loadedExtent_ = null;
/**
* @type {?import("../extent.js").Extent}
* @private
*/
this.renderedExtent_ = null;
/**
* @type {?number}
* @private
*/
this.renderedResolution_ = null;
this.setRenderOrder(null);
}
/**
* Strategy function for loading features based on the view's extent and
* resolution.
* @param {import("../extent.js").Extent} extent Extent.
* @param {number} resolution Resolution.
* @return {Array<import("../extent.js").Extent>} Extents.
*/
strategyFunction(extent, resolution) {
// extents may be passed in different worlds, to avoid endless loop we use only one
let realWorldExtent = extent.slice();
if (this.projection_ && this.getSource().getWrapX()) {
wrapExtentX(realWorldExtent, this.projection_);
}
if (this.loadedExtent_) {
if (
approximatelyEquals(this.loadedExtent_, realWorldExtent, resolution)
) {
// make sure result is exactly equal to previous extent
realWorldExtent = this.loadedExtent_.slice();
} else {
// we should not keep track of loaded extents
this.getSource().removeLoadedExtent(this.loadedExtent_);
}
}
return [realWorldExtent];
}
/**
* Update geometries in the source based on current view
* @param {import("../extent").Extent} extent Extent
* @param {number} resolution Resolution
* @param {import("../proj/Projection.js").default} projection Projection
*/
loaderFunction(extent, resolution, projection) {
this.loadedExtent_ = extent;
const source = this.getSource();
// only consider the intersection between our own extent & the requested one
const layerExtent = this.getExtent() || [
-Infinity,
-Infinity,
Infinity,
Infinity,
];
const renderExtent = getIntersection(layerExtent, extent);
if (
this.renderedExtent_ &&
equals(this.renderedExtent_, renderExtent) &&
this.renderedResolution_ === resolution
) {
return;
}
this.renderedExtent_ = renderExtent;
this.renderedResolution_ = resolution;
// bail out if nothing to render
if (isEmpty(renderExtent)) {
return;
}
// update projection info
const center = getCenter(renderExtent);
const squaredTolerance = (resolution * resolution) / 4;
const updateProjectionInfo =
!this.projection_ || !equivalentProjection(this.projection_, projection);
if (updateProjectionInfo) {
this.updateProjectionInfo_(projection);
}
this.createGraticule_(renderExtent, center, resolution, squaredTolerance);
// first make sure we have enough features in the pool
let featureCount = this.meridians_.length + this.parallels_.length;
if (this.meridiansLabels_) {
featureCount += this.meridians_.length;
}
if (this.parallelsLabels_) {
featureCount += this.parallels_.length;
}
let feature;
while (featureCount > this.featurePool_.length) {
feature = new Feature();
this.featurePool_.push(feature);
}
const featuresColl = source.getFeaturesCollection();
featuresColl.clear();
let poolIndex = 0;
// add features for the lines & labels
let i, l;
for (i = 0, l = this.meridians_.length; i < l; ++i) {
feature = this.featurePool_[poolIndex++];
feature.setGeometry(this.meridians_[i]);
feature.setStyle(this.lineStyle_);
featuresColl.push(feature);
}
for (i = 0, l = this.parallels_.length; i < l; ++i) {
feature = this.featurePool_[poolIndex++];
feature.setGeometry(this.parallels_[i]);
feature.setStyle(this.lineStyle_);
featuresColl.push(feature);
}
}
/**
* @param {number} lon Longitude.
* @param {number} minLat Minimal latitude.
* @param {number} maxLat Maximal latitude.
* @param {number} squaredTolerance Squared tolerance.
* @param {import("../extent.js").Extent} extent Extent.
* @param {number} index Index.
* @return {number} Index.
* @private
*/
addMeridian_(lon, minLat, maxLat, squaredTolerance, extent, index) {
const lineString = this.getMeridian_(
lon,
minLat,
maxLat,
squaredTolerance,
index
);
if (intersects(lineString.getExtent(), extent)) {
if (this.meridiansLabels_) {
const text = this.lonLabelFormatter_(lon);
if (index in this.meridiansLabels_) {
this.meridiansLabels_[index].text = text;
} else {
this.meridiansLabels_[index] = {
geom: new Point([]),
text: text,
};
}
}
this.meridians_[index++] = lineString;
}
return index;
}
/**
* @param {number} lat Latitude.
* @param {number} minLon Minimal longitude.
* @param {number} maxLon Maximal longitude.
* @param {number} squaredTolerance Squared tolerance.
* @param {import("../extent.js").Extent} extent Extent.
* @param {number} index Index.
* @return {number} Index.
* @private
*/
addParallel_(lat, minLon, maxLon, squaredTolerance, extent, index) {
const lineString = this.getParallel_(
lat,
minLon,
maxLon,
squaredTolerance,
index
);
if (intersects(lineString.getExtent(), extent)) {
if (this.parallelsLabels_) {
const text = this.latLabelFormatter_(lat);
if (index in this.parallelsLabels_) {
this.parallelsLabels_[index].text = text;
} else {
this.parallelsLabels_[index] = {
geom: new Point([]),
text: text,
};
}
}
this.parallels_[index++] = lineString;
}
return index;
}
/**
* @param {import("../render/Event.js").default} event Render event.
* @private
*/
drawLabels_(event) {
const rotation = event.frameState.viewState.rotation;
const resolution = event.frameState.viewState.resolution;
const size = event.frameState.size;
const extent = event.frameState.extent;
const rotationCenter = getCenter(extent);
let rotationExtent = extent;
if (rotation) {
const unrotatedWidth = size[0] * resolution;
const unrotatedHeight = size[1] * resolution;
rotationExtent = [
rotationCenter[0] - unrotatedWidth / 2,
rotationCenter[1] - unrotatedHeight / 2,
rotationCenter[0] + unrotatedWidth / 2,
rotationCenter[1] + unrotatedHeight / 2,
];
}
let startWorld = 0;
let endWorld = 0;
let labelsAtStart = this.latLabelPosition_ < 0.5;
const projectionExtent = this.projection_.getExtent();
const worldWidth = getWidth(projectionExtent);
if (
this.getSource().getWrapX() &&
this.projection_.canWrapX() &&
!containsExtent(projectionExtent, extent)
) {
startWorld = Math.floor((extent[0] - projectionExtent[0]) / worldWidth);
endWorld = Math.ceil((extent[2] - projectionExtent[2]) / worldWidth);
const inverted = Math.abs(rotation) > Math.PI / 2;
labelsAtStart = labelsAtStart !== inverted;
}
const vectorContext = getVectorContext(event);
for (let world = startWorld; world <= endWorld; ++world) {
let poolIndex = this.meridians_.length + this.parallels_.length;
let feature, index, l, textPoint;
if (this.meridiansLabels_) {
for (index = 0, l = this.meridiansLabels_.length; index < l; ++index) {
const lineString = this.meridians_[index];
if (!rotation && world === 0) {
textPoint = this.getMeridianPoint_(lineString, extent, index);
} else {
const clone = lineString.clone();
clone.translate(world * worldWidth, 0);
clone.rotate(-rotation, rotationCenter);
textPoint = this.getMeridianPoint_(clone, rotationExtent, index);
textPoint.rotate(rotation, rotationCenter);
}
feature = this.featurePool_[poolIndex++];
feature.setGeometry(textPoint);
feature.set('graticule_label', this.meridiansLabels_[index].text);
vectorContext.drawFeature(feature, this.lonLabelStyle_(feature));
}
}
if (this.parallelsLabels_) {
if (
(world === startWorld && labelsAtStart) ||
(world === endWorld && !labelsAtStart)
) {
for (index = 0, l = this.parallels_.length; index < l; ++index) {
const lineString = this.parallels_[index];
if (!rotation && world === 0) {
textPoint = this.getParallelPoint_(lineString, extent, index);
} else {
const clone = lineString.clone();
clone.translate(world * worldWidth, 0);
clone.rotate(-rotation, rotationCenter);
textPoint = this.getParallelPoint_(clone, rotationExtent, index);
textPoint.rotate(rotation, rotationCenter);
}
feature = this.featurePool_[poolIndex++];
feature.setGeometry(textPoint);
feature.set('graticule_label', this.parallelsLabels_[index].text);
vectorContext.drawFeature(feature, this.latLabelStyle_(feature));
}
}
}
}
}
/**
* @param {import("../extent.js").Extent} extent Extent.
* @param {import("../coordinate.js").Coordinate} center Center.
* @param {number} resolution Resolution.
* @param {number} squaredTolerance Squared tolerance.
* @private
*/
createGraticule_(extent, center, resolution, squaredTolerance) {
const interval = this.getInterval_(resolution);
if (interval == -1) {
this.meridians_.length = 0;
this.parallels_.length = 0;
if (this.meridiansLabels_) {
this.meridiansLabels_.length = 0;
}
if (this.parallelsLabels_) {
this.parallelsLabels_.length = 0;
}
return;
}
let wrapX = false;
const projectionExtent = this.projection_.getExtent();
const worldWidth = getWidth(projectionExtent);
if (
this.getSource().getWrapX() &&
this.projection_.canWrapX() &&
!containsExtent(projectionExtent, extent)
) {
if (getWidth(extent) >= worldWidth) {
extent[0] = projectionExtent[0];
extent[2] = projectionExtent[2];
} else {
wrapX = true;
}
}
// Constrain the center to fit into the extent available to the graticule
const validCenterP = [
clamp(center[0], this.minX_, this.maxX_),
clamp(center[1], this.minY_, this.maxY_),
];
// Transform the center to lon lat
// Some projections may have a void area at the poles
// so replace any NaN latitudes with the min or max value closest to a pole
const centerLonLat = this.toLonLatTransform_(validCenterP);
if (isNaN(centerLonLat[1])) {
centerLonLat[1] =
Math.abs(this.maxLat_) >= Math.abs(this.minLat_)
? this.maxLat_
: this.minLat_;
}
let centerLon = clamp(centerLonLat[0], this.minLon_, this.maxLon_);
let centerLat = clamp(centerLonLat[1], this.minLat_, this.maxLat_);
const maxLines = this.maxLines_;
let cnt, idx, lat, lon;
// Limit the extent to fit into the extent available to the graticule
let validExtentP = extent;
if (!wrapX) {
validExtentP = [
clamp(extent[0], this.minX_, this.maxX_),
clamp(extent[1], this.minY_, this.maxY_),
clamp(extent[2], this.minX_, this.maxX_),
clamp(extent[3], this.minY_, this.maxY_),
];
}
// Transform the extent to get the lon lat ranges for the edges of the extent
const validExtent = applyTransform(
validExtentP,
this.toLonLatTransform_,
undefined,
8
);
let maxLat = validExtent[3];
let maxLon = validExtent[2];
let minLat = validExtent[1];
let minLon = validExtent[0];
if (!wrapX) {
// Check if extremities of the world extent lie inside the extent
// (for example the pole in a polar projection)
// and extend the extent as appropriate
if (containsCoordinate(validExtentP, this.bottomLeft_)) {
minLon = this.minLon_;
minLat = this.minLat_;
}
if (containsCoordinate(validExtentP, this.bottomRight_)) {
maxLon = this.maxLon_;
minLat = this.minLat_;
}
if (containsCoordinate(validExtentP, this.topLeft_)) {
minLon = this.minLon_;
maxLat = this.maxLat_;
}
if (containsCoordinate(validExtentP, this.topRight_)) {
maxLon = this.maxLon_;
maxLat = this.maxLat_;
}
// The transformed center may also extend the lon lat ranges used for rendering
maxLat = clamp(maxLat, centerLat, this.maxLat_);
maxLon = clamp(maxLon, centerLon, this.maxLon_);
minLat = clamp(minLat, this.minLat_, centerLat);
minLon = clamp(minLon, this.minLon_, centerLon);
}
// Create meridians
centerLon = Math.floor(centerLon / interval) * interval;
lon = clamp(centerLon, this.minLon_, this.maxLon_);
idx = this.addMeridian_(lon, minLat, maxLat, squaredTolerance, extent, 0);
cnt = 0;
if (wrapX) {
while ((lon -= interval) >= minLon && cnt++ < maxLines) {
idx = this.addMeridian_(
lon,
minLat,
maxLat,
squaredTolerance,
extent,
idx
);
}
} else {
while (lon != this.minLon_ && cnt++ < maxLines) {
lon = Math.max(lon - interval, this.minLon_);
idx = this.addMeridian_(
lon,
minLat,
maxLat,
squaredTolerance,
extent,
idx
);
}
}
lon = clamp(centerLon, this.minLon_, this.maxLon_);
cnt = 0;
if (wrapX) {
while ((lon += interval) <= maxLon && cnt++ < maxLines) {
idx = this.addMeridian_(
lon,
minLat,
maxLat,
squaredTolerance,
extent,
idx
);
}
} else {
while (lon != this.maxLon_ && cnt++ < maxLines) {
lon = Math.min(lon + interval, this.maxLon_);
idx = this.addMeridian_(
lon,
minLat,
maxLat,
squaredTolerance,
extent,
idx
);
}
}
this.meridians_.length = idx;
if (this.meridiansLabels_) {
this.meridiansLabels_.length = idx;
}
// Create parallels
centerLat = Math.floor(centerLat / interval) * interval;
lat = clamp(centerLat, this.minLat_, this.maxLat_);
idx = this.addParallel_(lat, minLon, maxLon, squaredTolerance, extent, 0);
cnt = 0;
while (lat != this.minLat_ && cnt++ < maxLines) {
lat = Math.max(lat - interval, this.minLat_);
idx = this.addParallel_(
lat,
minLon,
maxLon,
squaredTolerance,
extent,
idx
);
}
lat = clamp(centerLat, this.minLat_, this.maxLat_);
cnt = 0;
while (lat != this.maxLat_ && cnt++ < maxLines) {
lat = Math.min(lat + interval, this.maxLat_);
idx = this.addParallel_(
lat,
minLon,
maxLon,
squaredTolerance,
extent,
idx
);
}
this.parallels_.length = idx;
if (this.parallelsLabels_) {
this.parallelsLabels_.length = idx;
}
}
/**
* @param {number} resolution Resolution.
* @return {number} The interval in degrees.
* @private
*/
getInterval_(resolution) {
const centerLon = this.projectionCenterLonLat_[0];
const centerLat = this.projectionCenterLonLat_[1];
let interval = -1;
const target = Math.pow(this.targetSize_ * resolution, 2);
/** @type {Array<number>} **/
const p1 = [];
/** @type {Array<number>} **/
const p2 = [];
for (let i = 0, ii = this.intervals_.length; i < ii; ++i) {
const delta = clamp(this.intervals_[i] / 2, 0, 90);
// Don't attempt to transform latitudes beyond the poles!
const clampedLat = clamp(centerLat, -90 + delta, 90 - delta);
p1[0] = centerLon - delta;
p1[1] = clampedLat - delta;
p2[0] = centerLon + delta;
p2[1] = clampedLat + delta;
this.fromLonLatTransform_(p1, p1);
this.fromLonLatTransform_(p2, p2);
const dist = Math.pow(p2[0] - p1[0], 2) + Math.pow(p2[1] - p1[1], 2);
if (dist <= target) {
break;
}
interval = this.intervals_[i];
}
return interval;
}
/**
* @param {number} lon Longitude.
* @param {number} minLat Minimal latitude.
* @param {number} maxLat Maximal latitude.
* @param {number} squaredTolerance Squared tolerance.
* @return {LineString} The meridian line string.
* @param {number} index Index.
* @private
*/
getMeridian_(lon, minLat, maxLat, squaredTolerance, index) {
const flatCoordinates = meridian(
lon,
minLat,
maxLat,
this.projection_,
squaredTolerance
);
let lineString = this.meridians_[index];
if (!lineString) {
lineString = new LineString(flatCoordinates, 'XY');
this.meridians_[index] = lineString;
} else {
lineString.setFlatCoordinates('XY', flatCoordinates);
lineString.changed();
}
return lineString;
}
/**
* @param {LineString} lineString Meridian
* @param {import("../extent.js").Extent} extent Extent.
* @param {number} index Index.
* @return {Point} Meridian point.
* @private
*/
getMeridianPoint_(lineString, extent, index) {
const flatCoordinates = lineString.getFlatCoordinates();
let bottom = 1;
let top = flatCoordinates.length - 1;
if (flatCoordinates[bottom] > flatCoordinates[top]) {
bottom = top;
top = 1;
}
const clampedBottom = Math.max(extent[1], flatCoordinates[bottom]);
const clampedTop = Math.min(extent[3], flatCoordinates[top]);
const lat = clamp(
extent[1] + Math.abs(extent[1] - extent[3]) * this.lonLabelPosition_,
clampedBottom,
clampedTop
);
const coordinate0 =
flatCoordinates[bottom - 1] +
((flatCoordinates[top - 1] - flatCoordinates[bottom - 1]) *
(lat - flatCoordinates[bottom])) /
(flatCoordinates[top] - flatCoordinates[bottom]);
const coordinate = [coordinate0, lat];
const point = this.meridiansLabels_[index].geom;
point.setCoordinates(coordinate);
return point;
}
/**
* Get the list of meridians. Meridians are lines of equal longitude.
* @return {Array<LineString>} The meridians.
* @api
*/
getMeridians() {
return this.meridians_;
}
/**
* @param {number} lat Latitude.
* @param {number} minLon Minimal longitude.
* @param {number} maxLon Maximal longitude.
* @param {number} squaredTolerance Squared tolerance.
* @return {LineString} The parallel line string.
* @param {number} index Index.
* @private
*/
getParallel_(lat, minLon, maxLon, squaredTolerance, index) {
const flatCoordinates = parallel(
lat,
minLon,
maxLon,
this.projection_,
squaredTolerance
);
let lineString = this.parallels_[index];
if (!lineString) {
lineString = new LineString(flatCoordinates, 'XY');
} else {
lineString.setFlatCoordinates('XY', flatCoordinates);
lineString.changed();
}
return lineString;
}
/**
* @param {LineString} lineString Parallels.
* @param {import("../extent.js").Extent} extent Extent.
* @param {number} index Index.
* @return {Point} Parallel point.
* @private
*/
getParallelPoint_(lineString, extent, index) {
const flatCoordinates = lineString.getFlatCoordinates();
let left = 0;
let right = flatCoordinates.length - 2;
if (flatCoordinates[left] > flatCoordinates[right]) {
left = right;
right = 0;
}
const clampedLeft = Math.max(extent[0], flatCoordinates[left]);
const clampedRight = Math.min(extent[2], flatCoordinates[right]);
const lon = clamp(
extent[0] + Math.abs(extent[0] - extent[2]) * this.latLabelPosition_,
clampedLeft,
clampedRight
);
const coordinate1 =
flatCoordinates[left + 1] +
((flatCoordinates[right + 1] - flatCoordinates[left + 1]) *
(lon - flatCoordinates[left])) /
(flatCoordinates[right] - flatCoordinates[left]);
const coordinate = [lon, coordinate1];
const point = this.parallelsLabels_[index].geom;
point.setCoordinates(coordinate);
return point;
}
/**
* Get the list of parallels. Parallels are lines of equal latitude.
* @return {Array<LineString>} The parallels.
* @api
*/
getParallels() {
return this.parallels_;
}
/**
* @param {import("../proj/Projection.js").default} projection Projection.
* @private
*/
updateProjectionInfo_(projection) {
const epsg4326Projection = getProjection('EPSG:4326');
const worldExtent = projection.getWorldExtent();
this.maxLat_ = worldExtent[3];
this.maxLon_ = worldExtent[2];
this.minLat_ = worldExtent[1];
this.minLon_ = worldExtent[0];
// If the world extent crosses the dateline define a custom transform to
// return longitudes which wrap the dateline
const toLonLatTransform = getTransform(projection, epsg4326Projection);
if (this.minLon_ < this.maxLon_) {
this.toLonLatTransform_ = toLonLatTransform;
} else {
const split = this.minLon_ + this.maxLon_ / 2;
this.maxLon_ += 360;
this.toLonLatTransform_ = function (coordinates, output, dimension) {
dimension = dimension || 2;
const lonLatCoordinates = toLonLatTransform(
coordinates,
output,
dimension
);
for (let i = 0, l = lonLatCoordinates.length; i < l; i += dimension) {
if (lonLatCoordinates[i] < split) {
lonLatCoordinates[i] += 360;
}
}
return lonLatCoordinates;
};
}
// Transform the extent to get the limits of the view projection extent
// which should be available to the graticule
this.fromLonLatTransform_ = getTransform(epsg4326Projection, projection);
const worldExtentP = applyTransform(
[this.minLon_, this.minLat_, this.maxLon_, this.maxLat_],
this.fromLonLatTransform_,
undefined,
8
);
this.minX_ = worldExtentP[0];
this.maxX_ = worldExtentP[2];
this.minY_ = worldExtentP[1];
this.maxY_ = worldExtentP[3];
// Determine the view projection coordinates of the extremities of the world extent
// as these may lie inside a view extent (for example the pole in a polar projection)
this.bottomLeft_ = this.fromLonLatTransform_([this.minLon_, this.minLat_]);
this.bottomRight_ = this.fromLonLatTransform_([this.maxLon_, this.minLat_]);
this.topLeft_ = this.fromLonLatTransform_([this.minLon_, this.maxLat_]);
this.topRight_ = this.fromLonLatTransform_([this.maxLon_, this.maxLat_]);
// Transform the projection center to lon lat
// Some projections may have a void area at the poles
// so replace any NaN latitudes with the min or max value closest to a pole
this.projectionCenterLonLat_ = this.toLonLatTransform_(
getCenter(projection.getExtent())
);
if (isNaN(this.projectionCenterLonLat_[1])) {
this.projectionCenterLonLat_[1] =
Math.abs(this.maxLat_) >= Math.abs(this.minLat_)
? this.maxLat_
: this.minLat_;
}
this.projection_ = projection;
}
}
export default Graticule;