Files
openlayers/src/ol/Graticule.js
2018-07-17 09:59:00 +02:00

724 lines
21 KiB
JavaScript

/**
* @module ol/Graticule
*/
import {degreesToStringHDMS} from './coordinate.js';
import {listen, unlistenByKey} from './events.js';
import {intersects, getCenter} from './extent.js';
import GeometryLayout from './geom/GeometryLayout.js';
import LineString from './geom/LineString.js';
import Point from './geom/Point.js';
import {meridian, parallel} from './geom/flat/geodesic.js';
import {clamp} from './math.js';
import {get as getProjection, equivalent as equivalentProjection, getTransform, transformExtent} from './proj.js';
import RenderEventType from './render/EventType.js';
import Fill from './style/Fill.js';
import Stroke from './style/Stroke.js';
import Text from './style/Text.js';
/**
* @type {module:ol/style/Stroke}
* @private
* @const
*/
const DEFAULT_STROKE_STYLE = new Stroke({
color: 'rgba(0,0,0,0.2)'
});
/**
* TODO can be configurable
* @type {Array.<number>}
* @private
*/
const INTERVALS = [
90, 45, 30, 20, 10, 5, 2, 1, 0.5, 0.2, 0.1, 0.05, 0.01, 0.005, 0.002, 0.001
];
/**
* @typedef {Object} GraticuleLabelDataType
* @property {module:ol/geom/Point} geom
* @property {string} text
*/
/**
* @typedef {Object} Options
* @property {module:ol/PluggableMap} [map] Reference to an
* {@link module:ol/Map~Map} object.
* @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 {module:ol/style/Stroke} [strokeStyle='rgba(0,0,0,0.2)'] The
* stroke style to use for drawing the graticule. If not provided, a not fully
* opaque black will be used.
* @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 {module:ol/style/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 {module:ol/style/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.
*/
/**
* Render a grid for a coordinate system on a map.
* @api
*/
class Graticule {
/**
* @param {module:ol/Graticule~Options=} opt_options Options.
*/
constructor(opt_options) {
const options = opt_options || {};
/**
* @type {module:ol/PluggableMap}
* @private
*/
this.map_ = null;
/**
* @type {?module:ol/events~EventsKey}
* @private
*/
this.postcomposeListenerKey_ = null;
/**
* @type {module:ol/proj/Projection}
*/
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.maxLatP_ = Infinity;
/**
* @type {number}
* @private
*/
this.maxLonP_ = Infinity;
/**
* @type {number}
* @private
*/
this.minLatP_ = -Infinity;
/**
* @type {number}
* @private
*/
this.minLonP_ = -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.<module:ol/geom/LineString>}
* @private
*/
this.meridians_ = [];
/**
* @type {Array.<module:ol/geom/LineString>}
* @private
*/
this.parallels_ = [];
/**
* @type {module:ol/style/Stroke}
* @private
*/
this.strokeStyle_ = options.strokeStyle !== undefined ? options.strokeStyle : DEFAULT_STROKE_STYLE;
/**
* @type {module:ol/proj~TransformFunction|undefined}
* @private
*/
this.fromLonLatTransform_ = undefined;
/**
* @type {module:ol/proj~TransformFunction|undefined}
* @private
*/
this.toLonLatTransform_ = undefined;
/**
* @type {module:ol/coordinate~Coordinate}
* @private
*/
this.projectionCenterLonLat_ = null;
/**
* @type {Array.<module:ol/Graticule~GraticuleLabelDataType>}
* @private
*/
this.meridiansLabels_ = null;
/**
* @type {Array.<module:ol/Graticule~GraticuleLabelDataType>}
* @private
*/
this.parallelsLabels_ = null;
if (options.showLabels == true) {
/**
* @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 {module:ol/style/Text}
* @private
*/
this.lonLabelStyle_ = options.lonLabelStyle !== undefined ? options.lonLabelStyle :
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
})
});
/**
* @type {module:ol/style/Text}
* @private
*/
this.latLabelStyle_ = options.latLabelStyle !== undefined ? options.latLabelStyle :
new Text({
font: '12px Calibri,sans-serif',
textAlign: 'end',
fill: new Fill({
color: 'rgba(0,0,0,1)'
}),
stroke: new Stroke({
color: 'rgba(255,255,255,1)',
width: 3
})
});
this.meridiansLabels_ = [];
this.parallelsLabels_ = [];
}
this.setMap(options.map !== undefined ? options.map : null);
}
/**
* @param {number} lon Longitude.
* @param {number} minLat Minimal latitude.
* @param {number} maxLat Maximal latitude.
* @param {number} squaredTolerance Squared tolerance.
* @param {module:ol/extent~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 textPoint = this.getMeridianPoint_(lineString, extent, index);
this.meridiansLabels_[index] = {
geom: textPoint,
text: this.lonLabelFormatter_(lon)
};
}
this.meridians_[index++] = lineString;
}
return index;
}
/**
* @param {module:ol/geom/LineString} lineString Meridian
* @param {module:ol/extent~Extent} extent Extent.
* @param {number} index Index.
* @return {module:ol/geom/Point} Meridian point.
* @private
*/
getMeridianPoint_(lineString, extent, index) {
const flatCoordinates = lineString.getFlatCoordinates();
const clampedBottom = Math.max(extent[1], flatCoordinates[1]);
const clampedTop = Math.min(extent[3], flatCoordinates[flatCoordinates.length - 1]);
const lat = clamp(
extent[1] + Math.abs(extent[1] - extent[3]) * this.lonLabelPosition_,
clampedBottom, clampedTop);
const coordinate = [flatCoordinates[0], lat];
let point;
if (index in this.meridiansLabels_) {
point = this.meridiansLabels_[index];
point.setCoordinates(coordinate);
} else {
point = new Point(coordinate);
}
return point;
}
/**
* @param {number} lat Latitude.
* @param {number} minLon Minimal longitude.
* @param {number} maxLon Maximal longitude.
* @param {number} squaredTolerance Squared tolerance.
* @param {module:ol/extent~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 textPoint = this.getParallelPoint_(lineString, extent, index);
this.parallelsLabels_[index] = {
geom: textPoint,
text: this.latLabelFormatter_(lat)
};
}
this.parallels_[index++] = lineString;
}
return index;
}
/**
* @param {module:ol/geom/LineString} lineString Parallels.
* @param {module:ol/extent~Extent} extent Extent.
* @param {number} index Index.
* @return {module:ol/geom/Point} Parallel point.
* @private
*/
getParallelPoint_(lineString, extent, index) {
const flatCoordinates = lineString.getFlatCoordinates();
const clampedLeft = Math.max(extent[0], flatCoordinates[0]);
const clampedRight = Math.min(extent[2], flatCoordinates[flatCoordinates.length - 2]);
const lon = clamp(
extent[0] + Math.abs(extent[0] - extent[2]) * this.latLabelPosition_,
clampedLeft, clampedRight);
const coordinate = [lon, flatCoordinates[1]];
let point;
if (index in this.parallelsLabels_) {
point = this.parallelsLabels_[index];
point.setCoordinates(coordinate);
} else {
point = new Point(coordinate);
}
return point;
}
/**
* @param {module:ol/extent~Extent} extent Extent.
* @param {module:ol/coordinate~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 = this.parallels_.length = 0;
if (this.meridiansLabels_) {
this.meridiansLabels_.length = 0;
}
if (this.parallelsLabels_) {
this.parallelsLabels_.length = 0;
}
return;
}
const centerLonLat = this.toLonLatTransform_(center);
let centerLon = centerLonLat[0];
let centerLat = centerLonLat[1];
const maxLines = this.maxLines_;
let cnt, idx, lat, lon;
let validExtent = [
Math.max(extent[0], this.minLonP_),
Math.max(extent[1], this.minLatP_),
Math.min(extent[2], this.maxLonP_),
Math.min(extent[3], this.maxLatP_)
];
validExtent = transformExtent(validExtent, this.projection_, 'EPSG:4326');
const maxLat = validExtent[3];
const maxLon = validExtent[2];
const minLat = validExtent[1];
const minLon = validExtent[0];
// 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;
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;
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 = INTERVALS.length; i < ii; ++i) {
const delta = INTERVALS[i] / 2;
p1[0] = centerLon - delta;
p1[1] = centerLat - delta;
p2[0] = centerLon + delta;
p2[1] = centerLat + 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 = INTERVALS[i];
}
return interval;
}
/**
* Get the map associated with this graticule.
* @return {module:ol/PluggableMap} The map.
* @api
*/
getMap() {
return this.map_;
}
/**
* @param {number} lon Longitude.
* @param {number} minLat Minimal latitude.
* @param {number} maxLat Maximal latitude.
* @param {number} squaredTolerance Squared tolerance.
* @return {module:ol/geom/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 = this.meridians_[index] = new LineString(flatCoordinates, GeometryLayout.XY);
} else {
lineString.setFlatCoordinates(GeometryLayout.XY, flatCoordinates);
lineString.changed();
}
return lineString;
}
/**
* Get the list of meridians. Meridians are lines of equal longitude.
* @return {Array.<module:ol/geom/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 {module:ol/geom/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, GeometryLayout.XY);
} else {
lineString.setFlatCoordinates(GeometryLayout.XY, flatCoordinates);
lineString.changed();
}
return lineString;
}
/**
* Get the list of parallels. Parallels are lines of equal latitude.
* @return {Array.<module:ol/geom/LineString>} The parallels.
* @api
*/
getParallels() {
return this.parallels_;
}
/**
* @param {module:ol/render/Event} e Event.
* @private
*/
handlePostCompose_(e) {
const vectorContext = e.vectorContext;
const frameState = e.frameState;
const extent = frameState.extent;
const viewState = frameState.viewState;
const center = viewState.center;
const projection = viewState.projection;
const resolution = viewState.resolution;
const pixelRatio = frameState.pixelRatio;
const squaredTolerance =
resolution * resolution / (4 * pixelRatio * pixelRatio);
const updateProjectionInfo = !this.projection_ ||
!equivalentProjection(this.projection_, projection);
if (updateProjectionInfo) {
this.updateProjectionInfo_(projection);
}
this.createGraticule_(extent, center, resolution, squaredTolerance);
// Draw the lines
vectorContext.setFillStrokeStyle(null, this.strokeStyle_);
let i, l, line;
for (i = 0, l = this.meridians_.length; i < l; ++i) {
line = this.meridians_[i];
vectorContext.drawGeometry(line);
}
for (i = 0, l = this.parallels_.length; i < l; ++i) {
line = this.parallels_[i];
vectorContext.drawGeometry(line);
}
let labelData;
if (this.meridiansLabels_) {
for (i = 0, l = this.meridiansLabels_.length; i < l; ++i) {
labelData = this.meridiansLabels_[i];
this.lonLabelStyle_.setText(labelData.text);
vectorContext.setTextStyle(this.lonLabelStyle_);
vectorContext.drawGeometry(labelData.geom);
}
}
if (this.parallelsLabels_) {
for (i = 0, l = this.parallelsLabels_.length; i < l; ++i) {
labelData = this.parallelsLabels_[i];
this.latLabelStyle_.setText(labelData.text);
vectorContext.setTextStyle(this.latLabelStyle_);
vectorContext.drawGeometry(labelData.geom);
}
}
}
/**
* @param {module:ol/proj/Projection} projection Projection.
* @private
*/
updateProjectionInfo_(projection) {
const epsg4326Projection = getProjection('EPSG:4326');
const worldExtent = projection.getWorldExtent();
const worldExtentP = transformExtent(worldExtent, epsg4326Projection, projection);
this.maxLat_ = worldExtent[3];
this.maxLon_ = worldExtent[2];
this.minLat_ = worldExtent[1];
this.minLon_ = worldExtent[0];
this.maxLatP_ = worldExtentP[3];
this.maxLonP_ = worldExtentP[2];
this.minLatP_ = worldExtentP[1];
this.minLonP_ = worldExtentP[0];
this.fromLonLatTransform_ = getTransform(epsg4326Projection, projection);
this.toLonLatTransform_ = getTransform(projection, epsg4326Projection);
this.projectionCenterLonLat_ = this.toLonLatTransform_(getCenter(projection.getExtent()));
this.projection_ = projection;
}
/**
* Set the map for this graticule. The graticule will be rendered on the
* provided map.
* @param {module:ol/PluggableMap} map Map.
* @api
*/
setMap(map) {
if (this.map_) {
unlistenByKey(this.postcomposeListenerKey_);
this.postcomposeListenerKey_ = null;
this.map_.render();
}
if (map) {
this.postcomposeListenerKey_ = listen(map, RenderEventType.POSTCOMPOSE, this.handlePostCompose_, this);
map.render();
}
this.map_ = map;
}
}
export default Graticule;