ol
Version:
OpenLayers mapping library
355 lines (339 loc) • 13 kB
JavaScript
/**
* @module ol/source/IIIF
*/
import {assert} from '../asserts.js';
import {getTopLeft} from '../extent.js';
import {Versions} from '../format/IIIFInfo.js';
import {toSize} from '../size.js';
import TileGrid from '../tilegrid/TileGrid.js';
import {DEFAULT_TILE_SIZE} from '../tilegrid/common.js';
import TileImage from './TileImage.js';
import {CustomTile} from './Zoomify.js';
/**
* @typedef {Object} Options
* @property {import("./Source.js").AttributionLike} [attributions] Attributions.
* @property {boolean} [attributionsCollapsible=true] Attributions are collapsible.
* @property {number} [cacheSize] Deprecated. Use the cacheSize option on the layer instead.
* @property {null|string} [crossOrigin] The value for the crossOrigin option of the request.
* @property {import("../extent.js").Extent} [extent=[0, -height, width, 0]] The extent.
* @property {string} [format='jpg'] Requested image format.
* @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 {import("../proj.js").ProjectionLike} [projection] Projection.
* @property {string} [quality] Requested IIIF image quality. Default is 'native'
* for version 1, 'default' for versions 2 and 3.
* @property {number} [reprojectionErrorThreshold=0.5] Maximum allowed reprojection error (in pixels).
* Higher values can increase reprojection performance, but decrease precision.
* @property {Array<number>} [resolutions] Supported resolutions as given in IIIF 'scaleFactors'
* @property {import("../size.js").Size} size Size of the image [width, height].
* @property {Array<import("../size.js").Size>} [sizes] Supported scaled image sizes.
* Content of the IIIF info.json 'sizes' property, but as array of Size objects.
* @property {import("./Source.js").State} [state] Source state.
* @property {Array<string>} [supports=[]] Supported IIIF region and size calculation
* features.
* @property {number} [tilePixelRatio] Tile pixel ratio.
* @property {number|import("../size.js").Size} [tileSize] Tile size.
* Same tile size is used for all zoom levels. If tile size is a number,
* a square tile is assumed. If the IIIF image service supports arbitrary
* tiling (sizeByH, sizeByW, sizeByWh or sizeByPct as well as regionByPx or regionByPct
* are supported), the default tilesize is 256.
* @property {number} [transition] Transition.
* @property {string} [url] Base URL of the IIIF Image service.
* This should be the same as the IIIF Image ID.
* @property {import("../format/IIIFInfo.js").Versions} [version=Versions.VERSION2] Service's IIIF Image API version.
* @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}.
*/
function formatPercentage(percentage) {
return percentage.toLocaleString('en', {maximumFractionDigits: 10});
}
/**
* @classdesc
* Layer source for IIIF Image API services.
* @api
*/
class IIIF extends TileImage {
/**
* @param {Options} [options] Tile source options. Use {@link import("../format/IIIFInfo.js").IIIFInfo}
* to parse Image API service information responses into constructor options.
* @api
*/
constructor(options) {
/**
* @type {Partial<Options>}
*/
const partialOptions = options || {};
let baseUrl = partialOptions.url || '';
baseUrl =
baseUrl +
(baseUrl.lastIndexOf('/') === baseUrl.length - 1 || baseUrl === ''
? ''
: '/');
const version = partialOptions.version || Versions.VERSION2;
const sizes = partialOptions.sizes || [];
const size = partialOptions.size;
assert(
size != undefined &&
Array.isArray(size) &&
size.length == 2 &&
!isNaN(size[0]) &&
size[0] > 0 &&
!isNaN(size[1]) &&
size[1] > 0,
'Missing or invalid `size`',
);
const width = size[0];
const height = size[1];
const tileSize = partialOptions.tileSize;
const tilePixelRatio = partialOptions.tilePixelRatio || 1;
const format = partialOptions.format || 'jpg';
const quality =
partialOptions.quality ||
(partialOptions.version == Versions.VERSION1 ? 'native' : 'default');
let resolutions = partialOptions.resolutions || [];
const supports = partialOptions.supports || [];
const extent = partialOptions.extent || [0, -height, width, 0];
const supportsListedSizes =
sizes != undefined && Array.isArray(sizes) && sizes.length > 0;
const supportsListedTiles =
tileSize !== undefined &&
((typeof tileSize === 'number' &&
Number.isInteger(tileSize) &&
tileSize > 0) ||
(Array.isArray(tileSize) && tileSize.length > 0));
const supportsArbitraryTiling =
supports != undefined &&
Array.isArray(supports) &&
(supports.includes('regionByPx') || supports.includes('regionByPct')) &&
(supports.includes('sizeByWh') ||
supports.includes('sizeByH') ||
supports.includes('sizeByW') ||
supports.includes('sizeByPct'));
let tileWidth, tileHeight, maxZoom;
resolutions.sort(function (a, b) {
return b - a;
});
if (supportsListedTiles || supportsArbitraryTiling) {
if (tileSize != undefined) {
if (
typeof tileSize === 'number' &&
Number.isInteger(tileSize) &&
tileSize > 0
) {
tileWidth = tileSize;
tileHeight = tileSize;
} else if (Array.isArray(tileSize) && tileSize.length > 0) {
if (
tileSize.length == 1 ||
(tileSize[1] == undefined && Number.isInteger(tileSize[0]))
) {
tileWidth = tileSize[0];
tileHeight = tileSize[0];
}
if (tileSize.length == 2) {
if (
Number.isInteger(tileSize[0]) &&
Number.isInteger(tileSize[1])
) {
tileWidth = tileSize[0];
tileHeight = tileSize[1];
} else if (
tileSize[0] == undefined &&
Number.isInteger(tileSize[1])
) {
tileWidth = tileSize[1];
tileHeight = tileSize[1];
}
}
}
}
if (tileWidth === undefined || tileHeight === undefined) {
tileWidth = DEFAULT_TILE_SIZE;
tileHeight = DEFAULT_TILE_SIZE;
}
if (resolutions.length == 0) {
maxZoom = Math.max(
Math.ceil(Math.log(width / tileWidth) / Math.LN2),
Math.ceil(Math.log(height / tileHeight) / Math.LN2),
);
for (let i = maxZoom; i >= 0; i--) {
resolutions.push(Math.pow(2, i));
}
} else {
const maxScaleFactor = Math.max(...resolutions);
// TODO maxScaleFactor might not be a power to 2
maxZoom = Math.round(Math.log(maxScaleFactor) / Math.LN2);
}
} else {
// No tile support.
tileWidth = width;
tileHeight = height;
resolutions = [];
if (supportsListedSizes) {
/*
* 'sizes' provided. Use full region in different resolutions. Every
* resolution has only one tile.
*/
sizes.sort(function (a, b) {
return a[0] - b[0];
});
maxZoom = -1;
const ignoredSizesIndex = [];
for (let i = 0; i < sizes.length; i++) {
const resolution = width / sizes[i][0];
if (
resolutions.length > 0 &&
resolutions[resolutions.length - 1] == resolution
) {
ignoredSizesIndex.push(i);
continue;
}
resolutions.push(resolution);
maxZoom++;
}
if (ignoredSizesIndex.length > 0) {
for (let i = 0; i < ignoredSizesIndex.length; i++) {
sizes.splice(ignoredSizesIndex[i] - i, 1);
}
}
} else {
// No useful image information at all. Try pseudo tile with full image.
resolutions.push(1);
sizes.push([width, height]);
maxZoom = 0;
}
}
const tileGrid = new TileGrid({
tileSize: [tileWidth, tileHeight],
extent: extent,
origin: getTopLeft(extent),
resolutions: resolutions,
});
const tileUrlFunction = function (tileCoord, pixelRatio, projection) {
let regionParam, sizeParam;
const zoom = tileCoord[0];
if (zoom > maxZoom) {
return;
}
const tileX = tileCoord[1],
tileY = tileCoord[2],
scale = resolutions[zoom];
if (
tileX === undefined ||
tileY === undefined ||
scale === undefined ||
tileX < 0 ||
Math.ceil(width / scale / tileWidth) <= tileX ||
tileY < 0 ||
Math.ceil(height / scale / tileHeight) <= tileY
) {
return;
}
if (supportsArbitraryTiling || supportsListedTiles) {
const regionX = tileX * tileWidth * scale,
regionY = tileY * tileHeight * scale;
let regionW = tileWidth * scale,
regionH = tileHeight * scale,
sizeW = tileWidth,
sizeH = tileHeight;
if (regionX + regionW > width) {
regionW = width - regionX;
}
if (regionY + regionH > height) {
regionH = height - regionY;
}
if (regionX + tileWidth * scale > width) {
sizeW = Math.floor((width - regionX + scale - 1) / scale);
}
if (regionY + tileHeight * scale > height) {
sizeH = Math.floor((height - regionY + scale - 1) / scale);
}
if (
regionX == 0 &&
regionW == width &&
regionY == 0 &&
regionH == height
) {
// canonical full image region parameter is 'full', not 'x,y,w,h'
regionParam = 'full';
} else if (
!supportsArbitraryTiling ||
supports.includes('regionByPx')
) {
regionParam = regionX + ',' + regionY + ',' + regionW + ',' + regionH;
} else if (supports.includes('regionByPct')) {
const pctX = formatPercentage((regionX / width) * 100),
pctY = formatPercentage((regionY / height) * 100),
pctW = formatPercentage((regionW / width) * 100),
pctH = formatPercentage((regionH / height) * 100);
regionParam = 'pct:' + pctX + ',' + pctY + ',' + pctW + ',' + pctH;
}
if (
version == Versions.VERSION3 &&
(!supportsArbitraryTiling || supports.includes('sizeByWh'))
) {
sizeParam = sizeW + ',' + sizeH;
} else if (!supportsArbitraryTiling || supports.includes('sizeByW')) {
sizeParam = sizeW + ',';
} else if (supports.includes('sizeByH')) {
sizeParam = ',' + sizeH;
} else if (supports.includes('sizeByWh')) {
sizeParam = sizeW + ',' + sizeH;
} else if (supports.includes('sizeByPct')) {
sizeParam = 'pct:' + formatPercentage(100 / scale);
}
} else {
regionParam = 'full';
if (supportsListedSizes) {
const regionWidth = sizes[zoom][0],
regionHeight = sizes[zoom][1];
if (version == Versions.VERSION3) {
if (regionWidth == width && regionHeight == height) {
sizeParam = 'max';
} else {
sizeParam = regionWidth + ',' + regionHeight;
}
} else {
if (regionWidth == width) {
sizeParam = 'full';
} else {
sizeParam = regionWidth + ',';
}
}
} else {
sizeParam = version == Versions.VERSION3 ? 'max' : 'full';
}
}
return (
baseUrl + regionParam + '/' + sizeParam + '/0/' + quality + '.' + format
);
};
const IiifTileClass = CustomTile.bind(
null,
toSize(tileSize || 256).map(function (size) {
return size * tilePixelRatio;
}),
);
super({
attributions: partialOptions.attributions,
attributionsCollapsible: partialOptions.attributionsCollapsible,
cacheSize: partialOptions.cacheSize,
crossOrigin: partialOptions.crossOrigin,
interpolate: partialOptions.interpolate,
projection: partialOptions.projection,
reprojectionErrorThreshold: partialOptions.reprojectionErrorThreshold,
state: partialOptions.state,
tileClass: IiifTileClass,
tileGrid: tileGrid,
tilePixelRatio: partialOptions.tilePixelRatio,
tileUrlFunction: tileUrlFunction,
transition: partialOptions.transition,
});
/**
* @type {number|import("../array.js").NearestDirectionFunction}
*/
this.zDirection = partialOptions.zDirection;
}
}
export default IIIF;