Files
openlayers/src/ol/source/TileImage.js
2022-07-15 10:46:44 +02:00

472 lines
16 KiB
JavaScript

/**
* @module ol/source/TileImage
*/
import EventType from '../events/EventType.js';
import ImageTile from '../ImageTile.js';
import ReprojTile from '../reproj/Tile.js';
import TileCache from '../TileCache.js';
import TileState from '../TileState.js';
import UrlTile from './UrlTile.js';
import {ENABLE_RASTER_REPROJECTION} from '../reproj/common.js';
import {equivalent, get as getProjection} from '../proj.js';
import {getKey, getKeyZXY} from '../tilecoord.js';
import {getForProjection as getTileGridForProjection} from '../tilegrid.js';
import {getUid} from '../util.js';
/**
* @typedef {Object} Options
* @property {import("./Source.js").AttributionLike} [attributions] Attributions.
* @property {boolean} [attributionsCollapsible=true] Attributions are collapsible.
* @property {number} [cacheSize] Initial tile cache size. Will auto-grow to hold at least the number of tiles in the viewport.
* @property {null|string} [crossOrigin] The `crossOrigin` attribute for loaded images. Note that
* you must provide a `crossOrigin` value if you want to access pixel data with the Canvas renderer.
* See https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image for more detail.
* @property {boolean} [imageSmoothing=true] Deprecated. Use the `interpolate` option instead.
* @property {boolean} [interpolate=true] Use interpolated values when resampling. By default,
* linear interpolation is used when resampling. Set to false to use the nearest neighbor instead.
* @property {boolean} [opaque=false] Whether the layer is opaque.
* @property {import("../proj.js").ProjectionLike} [projection] Projection. Default is the view projection.
* @property {number} [reprojectionErrorThreshold=0.5] Maximum allowed reprojection error (in pixels).
* Higher values can increase reprojection performance, but decrease precision.
* @property {import("./Source.js").State} [state] Source state.
* @property {typeof import("../ImageTile.js").default} [tileClass] Class used to instantiate image tiles.
* Default is {@link module:ol/ImageTile~ImageTile}.
* @property {import("../tilegrid/TileGrid.js").default} [tileGrid] Tile grid.
* @property {import("../Tile.js").LoadFunction} [tileLoadFunction] Optional function to load a tile given a URL. The default is
* ```js
* function(imageTile, src) {
* imageTile.getImage().src = src;
* };
* ```
* @property {number} [tilePixelRatio=1] The pixel ratio used by the tile service. For example, if the tile
* service advertizes 256px by 256px tiles but actually sends 512px
* by 512px images (for retina/hidpi devices) then `tilePixelRatio`
* should be set to `2`.
* @property {import("../Tile.js").UrlFunction} [tileUrlFunction] Optional function to get tile URL given a tile coordinate and the projection.
* @property {string} [url] URL template. Must include `{x}`, `{y}` or `{-y}`, and `{z}` placeholders.
* A `{?-?}` template pattern, for example `subdomain{a-f}.domain.com`, may be
* used instead of defining each one separately in the `urls` option.
* @property {Array<string>} [urls] An array of URL templates.
* @property {boolean} [wrapX] Whether to wrap the world horizontally. The default, is to
* request out-of-bounds tiles from the server. When set to `false`, only one
* world will be rendered. When set to `true`, tiles will be requested for one
* world only, but they will be wrapped horizontally to render multiple worlds.
* @property {number} [transition] Duration of the opacity transition for rendering.
* To disable the opacity transition, pass `transition: 0`.
* @property {string} [key] Optional tile key for proper cache fetching
* @property {number|import("../array.js").NearestDirectionFunction} [zDirection=0]
* Choose whether to use tiles with a higher or lower zoom level when between integer
* zoom levels. See {@link module:ol/tilegrid/TileGrid~TileGrid#getZForResolution}.
*/
/**
* @classdesc
* Base class for sources providing images divided into a tile grid.
*
* @fires import("./Tile.js").TileSourceEvent
* @api
*/
class TileImage extends UrlTile {
/**
* @param {!Options} options Image tile options.
*/
constructor(options) {
let interpolate =
options.imageSmoothing !== undefined ? options.imageSmoothing : true;
if (options.interpolate !== undefined) {
interpolate = options.interpolate;
}
super({
attributions: options.attributions,
cacheSize: options.cacheSize,
opaque: options.opaque,
projection: options.projection,
state: options.state,
tileGrid: options.tileGrid,
tileLoadFunction: options.tileLoadFunction
? options.tileLoadFunction
: defaultTileLoadFunction,
tilePixelRatio: options.tilePixelRatio,
tileUrlFunction: options.tileUrlFunction,
url: options.url,
urls: options.urls,
wrapX: options.wrapX,
transition: options.transition,
interpolate: interpolate,
key: options.key,
attributionsCollapsible: options.attributionsCollapsible,
zDirection: options.zDirection,
});
/**
* @protected
* @type {?string}
*/
this.crossOrigin =
options.crossOrigin !== undefined ? options.crossOrigin : null;
/**
* @protected
* @type {typeof ImageTile}
*/
this.tileClass =
options.tileClass !== undefined ? options.tileClass : ImageTile;
/**
* @protected
* @type {!Object<string, TileCache>}
*/
this.tileCacheForProjection = {};
/**
* @protected
* @type {!Object<string, import("../tilegrid/TileGrid.js").default>}
*/
this.tileGridForProjection = {};
/**
* @private
* @type {number|undefined}
*/
this.reprojectionErrorThreshold_ = options.reprojectionErrorThreshold;
/**
* @private
* @type {boolean}
*/
this.renderReprojectionEdges_ = false;
}
/**
* @return {boolean} Can expire cache.
*/
canExpireCache() {
if (!ENABLE_RASTER_REPROJECTION) {
return super.canExpireCache();
}
if (this.tileCache.canExpireCache()) {
return true;
} else {
for (const key in this.tileCacheForProjection) {
if (this.tileCacheForProjection[key].canExpireCache()) {
return true;
}
}
}
return false;
}
/**
* @param {import("../proj/Projection.js").default} projection Projection.
* @param {!Object<string, boolean>} usedTiles Used tiles.
*/
expireCache(projection, usedTiles) {
if (!ENABLE_RASTER_REPROJECTION) {
super.expireCache(projection, usedTiles);
return;
}
const usedTileCache = this.getTileCacheForProjection(projection);
this.tileCache.expireCache(
this.tileCache == usedTileCache ? usedTiles : {}
);
for (const id in this.tileCacheForProjection) {
const tileCache = this.tileCacheForProjection[id];
tileCache.expireCache(tileCache == usedTileCache ? usedTiles : {});
}
}
/**
* @param {import("../proj/Projection.js").default} projection Projection.
* @return {number} Gutter.
*/
getGutterForProjection(projection) {
if (
ENABLE_RASTER_REPROJECTION &&
this.getProjection() &&
projection &&
!equivalent(this.getProjection(), projection)
) {
return 0;
} else {
return this.getGutter();
}
}
/**
* @return {number} Gutter.
*/
getGutter() {
return 0;
}
/**
* Return the key to be used for all tiles in the source.
* @return {string} The key for all tiles.
*/
getKey() {
let key = super.getKey();
if (!this.getInterpolate()) {
key += ':disable-interpolation';
}
return key;
}
/**
* @param {import("../proj/Projection.js").default} projection Projection.
* @return {boolean} Opaque.
*/
getOpaque(projection) {
if (
ENABLE_RASTER_REPROJECTION &&
this.getProjection() &&
projection &&
!equivalent(this.getProjection(), projection)
) {
return false;
} else {
return super.getOpaque(projection);
}
}
/**
* @param {import("../proj/Projection.js").default} projection Projection.
* @return {!import("../tilegrid/TileGrid.js").default} Tile grid.
*/
getTileGridForProjection(projection) {
if (!ENABLE_RASTER_REPROJECTION) {
return super.getTileGridForProjection(projection);
}
const thisProj = this.getProjection();
if (this.tileGrid && (!thisProj || equivalent(thisProj, projection))) {
return this.tileGrid;
} else {
const projKey = getUid(projection);
if (!(projKey in this.tileGridForProjection)) {
this.tileGridForProjection[projKey] =
getTileGridForProjection(projection);
}
return this.tileGridForProjection[projKey];
}
}
/**
* @param {import("../proj/Projection.js").default} projection Projection.
* @return {import("../TileCache.js").default} Tile cache.
*/
getTileCacheForProjection(projection) {
if (!ENABLE_RASTER_REPROJECTION) {
return super.getTileCacheForProjection(projection);
}
const thisProj = this.getProjection();
if (!thisProj || equivalent(thisProj, projection)) {
return this.tileCache;
} else {
const projKey = getUid(projection);
if (!(projKey in this.tileCacheForProjection)) {
this.tileCacheForProjection[projKey] = new TileCache(
this.tileCache.highWaterMark
);
}
return this.tileCacheForProjection[projKey];
}
}
/**
* @param {number} z Tile coordinate z.
* @param {number} x Tile coordinate x.
* @param {number} y Tile coordinate y.
* @param {number} pixelRatio Pixel ratio.
* @param {import("../proj/Projection.js").default} projection Projection.
* @param {string} key The key set on the tile.
* @return {!ImageTile} Tile.
* @private
*/
createTile_(z, x, y, pixelRatio, projection, key) {
const tileCoord = [z, x, y];
const urlTileCoord = this.getTileCoordForTileUrlFunction(
tileCoord,
projection
);
const tileUrl = urlTileCoord
? this.tileUrlFunction(urlTileCoord, pixelRatio, projection)
: undefined;
const tile = new this.tileClass(
tileCoord,
tileUrl !== undefined ? TileState.IDLE : TileState.EMPTY,
tileUrl !== undefined ? tileUrl : '',
this.crossOrigin,
this.tileLoadFunction,
this.tileOptions
);
tile.key = key;
tile.addEventListener(EventType.CHANGE, this.handleTileChange.bind(this));
return tile;
}
/**
* @param {number} z Tile coordinate z.
* @param {number} x Tile coordinate x.
* @param {number} y Tile coordinate y.
* @param {number} pixelRatio Pixel ratio.
* @param {import("../proj/Projection.js").default} projection Projection.
* @return {!(ImageTile|ReprojTile)} Tile.
*/
getTile(z, x, y, pixelRatio, projection) {
const sourceProjection = this.getProjection();
if (
!ENABLE_RASTER_REPROJECTION ||
!sourceProjection ||
!projection ||
equivalent(sourceProjection, projection)
) {
return this.getTileInternal(
z,
x,
y,
pixelRatio,
sourceProjection || projection
);
} else {
const cache = this.getTileCacheForProjection(projection);
const tileCoord = [z, x, y];
let tile;
const tileCoordKey = getKey(tileCoord);
if (cache.containsKey(tileCoordKey)) {
tile = cache.get(tileCoordKey);
}
const key = this.getKey();
if (tile && tile.key == key) {
return tile;
} else {
const sourceTileGrid = this.getTileGridForProjection(sourceProjection);
const targetTileGrid = this.getTileGridForProjection(projection);
const wrappedTileCoord = this.getTileCoordForTileUrlFunction(
tileCoord,
projection
);
const newTile = new ReprojTile(
sourceProjection,
sourceTileGrid,
projection,
targetTileGrid,
tileCoord,
wrappedTileCoord,
this.getTilePixelRatio(pixelRatio),
this.getGutter(),
function (z, x, y, pixelRatio) {
return this.getTileInternal(z, x, y, pixelRatio, sourceProjection);
}.bind(this),
this.reprojectionErrorThreshold_,
this.renderReprojectionEdges_,
this.getInterpolate()
);
newTile.key = key;
if (tile) {
newTile.interimTile = tile;
newTile.refreshInterimChain();
cache.replace(tileCoordKey, newTile);
} else {
cache.set(tileCoordKey, newTile);
}
return newTile;
}
}
}
/**
* @param {number} z Tile coordinate z.
* @param {number} x Tile coordinate x.
* @param {number} y Tile coordinate y.
* @param {number} pixelRatio Pixel ratio.
* @param {!import("../proj/Projection.js").default} projection Projection.
* @return {!(ImageTile|ReprojTile)} Tile.
* @protected
*/
getTileInternal(z, x, y, pixelRatio, projection) {
let tile = null;
const tileCoordKey = getKeyZXY(z, x, y);
const key = this.getKey();
if (!this.tileCache.containsKey(tileCoordKey)) {
tile = this.createTile_(z, x, y, pixelRatio, projection, key);
this.tileCache.set(tileCoordKey, tile);
} else {
tile = this.tileCache.get(tileCoordKey);
if (tile.key != key) {
// The source's params changed. If the tile has an interim tile and if we
// can use it then we use it. Otherwise we create a new tile. In both
// cases we attempt to assign an interim tile to the new tile.
const interimTile = tile;
tile = this.createTile_(z, x, y, pixelRatio, projection, key);
//make the new tile the head of the list,
if (interimTile.getState() == TileState.IDLE) {
//the old tile hasn't begun loading yet, and is now outdated, so we can simply discard it
tile.interimTile = interimTile.interimTile;
} else {
tile.interimTile = interimTile;
}
tile.refreshInterimChain();
this.tileCache.replace(tileCoordKey, tile);
}
}
return tile;
}
/**
* Sets whether to render reprojection edges or not (usually for debugging).
* @param {boolean} render Render the edges.
* @api
*/
setRenderReprojectionEdges(render) {
if (
!ENABLE_RASTER_REPROJECTION ||
this.renderReprojectionEdges_ == render
) {
return;
}
this.renderReprojectionEdges_ = render;
for (const id in this.tileCacheForProjection) {
this.tileCacheForProjection[id].clear();
}
this.changed();
}
/**
* Sets the tile grid to use when reprojecting the tiles to the given
* projection instead of the default tile grid for the projection.
*
* This can be useful when the default tile grid cannot be created
* (e.g. projection has no extent defined) or
* for optimization reasons (custom tile size, resolutions, ...).
*
* @param {import("../proj.js").ProjectionLike} projection Projection.
* @param {import("../tilegrid/TileGrid.js").default} tilegrid Tile grid to use for the projection.
* @api
*/
setTileGridForProjection(projection, tilegrid) {
if (ENABLE_RASTER_REPROJECTION) {
const proj = getProjection(projection);
if (proj) {
const projKey = getUid(proj);
if (!(projKey in this.tileGridForProjection)) {
this.tileGridForProjection[projKey] = tilegrid;
}
}
}
}
}
/**
* @param {ImageTile} imageTile Image tile.
* @param {string} src Source.
*/
function defaultTileLoadFunction(imageTile, src) {
/** @type {HTMLImageElement|HTMLVideoElement} */ (imageTile.getImage()).src =
src;
}
export default TileImage;