Files
openlayers/src/ol/renderer/canvas/TileLayer.js
2018-11-16 14:57:13 +01:00

370 lines
12 KiB
JavaScript

/**
* @module ol/renderer/canvas/TileLayer
*/
import {getUid} from '../../util.js';
import TileRange from '../../TileRange.js';
import TileState from '../../TileState.js';
import {createEmpty, getIntersection, getTopLeft} from '../../extent.js';
import CanvasLayerRenderer from './Layer.js';
import {create as createTransform, compose as composeTransform, toString as transformToString} from '../../transform.js';
/**
* @classdesc
* Canvas renderer for tile layers.
* @api
*/
class CanvasTileLayerRenderer extends CanvasLayerRenderer {
/**
* @param {import("../../layer/Tile.js").default|import("../../layer/VectorTile.js").default} tileLayer Tile layer.
*/
constructor(tileLayer) {
super(tileLayer);
/**
* @protected
* @type {import("../../transform.js").Transform}
*/
this.coordinateToCanvasPixelTransform = createTransform();
/**
* @private
* @type {number}
*/
this.oversampling_;
/**
* @private
* @type {import("../../extent.js").Extent}
*/
this.renderedExtent_ = null;
/**
* @protected
* @type {number}
*/
this.renderedRevision;
/**
* @protected
* @type {!Array<import("../../Tile.js").default>}
*/
this.renderedTiles = [];
/**
* @private
* @type {boolean}
*/
this.newTiles_ = false;
/**
* @protected
* @type {import("../../extent.js").Extent}
*/
this.tmpExtent = createEmpty();
/**
* @private
* @type {import("../../TileRange.js").default}
*/
this.tmpTileRange_ = new TileRange(0, 0, 0, 0);
/**
* @protected
* @type {number}
*/
this.zDirection = 0;
}
/**
* @private
* @param {import("../../Tile.js").default} tile Tile.
* @return {boolean} Tile is drawable.
*/
isDrawableTile_(tile) {
const tileLayer = /** @type {import("../../layer/Tile.js").default} */ (this.getLayer());
const tileState = tile.getState();
const useInterimTilesOnError = tileLayer.getUseInterimTilesOnError();
return tileState == TileState.LOADED ||
tileState == TileState.EMPTY ||
tileState == TileState.ERROR && !useInterimTilesOnError;
}
/**
* @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 {!import("../../Tile.js").default} Tile.
*/
getTile(z, x, y, pixelRatio, projection) {
const tileLayer = /** @type {import("../../layer/Tile.js").default} */ (this.getLayer());
const tileSource = /** @type {import("../../source/Tile.js").default} */ (tileLayer.getSource());
let tile = tileSource.getTile(z, x, y, pixelRatio, projection);
if (tile.getState() == TileState.ERROR) {
if (!tileLayer.getUseInterimTilesOnError()) {
// When useInterimTilesOnError is false, we consider the error tile as loaded.
tile.setState(TileState.LOADED);
} else if (tileLayer.getPreload() > 0) {
// Preloaded tiles for lower resolutions might have finished loading.
this.newTiles_ = true;
}
}
if (!this.isDrawableTile_(tile)) {
tile = tile.getInterimTile();
}
return tile;
}
/**
* @inheritDoc
*/
prepareFrame(frameState, layerState) {
return true;
}
/**
* @inheritDoc
*/
renderFrame(frameState, layerState) {
const context = this.context;
const viewState = frameState.viewState;
const projection = viewState.projection;
const viewResolution = viewState.resolution;
const viewCenter = viewState.center;
const rotation = viewState.rotation;
const pixelRatio = frameState.pixelRatio;
const tileLayer = /** @type {import("../../layer/Tile.js").default} */ (this.getLayer());
const tileSource = /** @type {import("../../source/Tile.js").default} */ (tileLayer.getSource());
const sourceRevision = tileSource.getRevision();
const tileGrid = tileSource.getTileGridForProjection(projection);
const z = tileGrid.getZForResolution(viewResolution, this.zDirection);
const tileResolution = tileGrid.getResolution(z);
let extent = frameState.extent;
if (layerState.extent !== undefined) {
extent = getIntersection(extent, layerState.extent);
}
// TODO: clip by layer extent
const tilePixelRatio = tileSource.getTilePixelRatio(pixelRatio);
// desired dimensions of the canvas in pixels
let width = Math.round(frameState.size[0] * tilePixelRatio);
let height = Math.round(frameState.size[1] * tilePixelRatio);
if (tileResolution < viewResolution) {
// scale canvas so it covers the viewport until new tiles come it
width *= 1.5;
height *= 1.5;
}
if (rotation) {
const size = Math.round(Math.sqrt(width * width + height * height));
width = height = size;
}
const dx = tileResolution * width / 2 / tilePixelRatio;
const dy = tileResolution * height / 2 / tilePixelRatio;
const canvasExtent = [
viewCenter[0] - dx,
viewCenter[1] - dy,
viewCenter[0] + dx,
viewCenter[1] + dy
];
const tileRange = tileGrid.getTileRangeForExtentAndZ(canvasExtent, z);
/**
* @type {Object<number, Object<string, import("../../Tile.js").default>>}
*/
const tilesToDrawByZ = {};
tilesToDrawByZ[z] = {};
const findLoadedTiles = this.createLoadedTileFinder(tileSource, projection, tilesToDrawByZ);
const tmpExtent = this.tmpExtent;
const tmpTileRange = this.tmpTileRange_;
this.newTiles_ = false;
for (let x = tileRange.minX; x <= tileRange.maxX; ++x) {
for (let y = tileRange.minY; y <= tileRange.maxY; ++y) {
const tile = this.getTile(z, x, y, pixelRatio, projection);
if (this.isDrawableTile_(tile)) {
const uid = getUid(this);
if (tile.getState() == TileState.LOADED) {
tilesToDrawByZ[z][tile.tileCoord.toString()] = tile;
const inTransition = tile.inTransition(uid);
if (!this.newTiles_ && (inTransition || this.renderedTiles.indexOf(tile) === -1)) {
this.newTiles_ = true;
}
}
if (tile.getAlpha(uid, frameState.time) === 1) {
// don't look for alt tiles if alpha is 1
continue;
}
}
const childTileRange = tileGrid.getTileCoordChildTileRange(tile.tileCoord, tmpTileRange, tmpExtent);
let covered = false;
if (childTileRange) {
covered = findLoadedTiles(z + 1, childTileRange);
}
if (!covered) {
tileGrid.forEachTileCoordParentTileRange(tile.tileCoord, findLoadedTiles, null, tmpTileRange, tmpExtent);
}
}
}
const canvas = context.canvas;
const canvasScale = tileResolution / frameState.viewState.resolution / tilePixelRatio;
const pixelTransform = composeTransform(this.transform_,
0, 0,
canvasScale, canvasScale,
rotation,
0, 0
);
const canvasTransform = transformToString(pixelTransform);
if (canvas.width != width || canvas.height != height) {
canvas.width = width;
canvas.height = height;
} else {
context.clearRect(0, 0, width, height);
}
this.preRender(context, frameState, pixelTransform);
this.renderedTiles.length = 0;
/** @type {Array<number>} */
const zs = Object.keys(tilesToDrawByZ).map(Number);
zs.sort(function(a, b) {
if (a === z) {
return 1;
} else if (b === z) {
return -1;
} else {
return a > b ? 1 : a < b ? -1 : 0;
}
});
for (let i = 0, ii = zs.length; i < ii; ++i) {
const currentZ = zs[i];
const currentTilePixelSize = tileSource.getTilePixelSize(currentZ, pixelRatio, projection);
const currentResolution = tileGrid.getResolution(currentZ);
const currentScale = currentResolution / tileResolution;
const w = currentTilePixelSize[0] * currentScale;
const h = currentTilePixelSize[1] * currentScale;
const originTileCoord = tileGrid.getTileCoordForCoordAndZ(getTopLeft(canvasExtent), currentZ);
const originTileExtent = tileGrid.getTileCoordExtent(originTileCoord);
const originX = Math.round(tilePixelRatio * (originTileExtent[0] - canvasExtent[0]) / tileResolution);
const originY = Math.round(tilePixelRatio * (canvasExtent[3] - originTileExtent[3]) / tileResolution);
const tileGutter = tilePixelRatio * tileSource.getGutterForProjection(projection);
const tilesToDraw = tilesToDrawByZ[currentZ];
for (const tileCoordKey in tilesToDraw) {
const tile = tilesToDraw[tileCoordKey];
const tileCoord = tile.tileCoord;
const x = originX - (originTileCoord[1] - tileCoord[1]) * w;
const y = originY + (originTileCoord[2] - tileCoord[2]) * h;
this.drawTileImage(tile, frameState, layerState, x, y, w, h, tileGutter, z === currentZ);
this.renderedTiles.push(tile);
}
}
this.renderedRevision = sourceRevision;
this.renderedResolution = tileResolution;
this.renderedExtent_ = canvasExtent;
this.updateUsedTiles(frameState.usedTiles, tileSource, z, tileRange);
this.manageTilePyramid(frameState, tileSource, tileGrid, pixelRatio,
projection, extent, z, tileLayer.getPreload());
this.scheduleExpireCache(frameState, tileSource);
this.postRender(context, frameState, pixelTransform);
const opacity = layerState.opacity;
if (opacity !== canvas.style.opacity) {
canvas.style.opacity = opacity;
}
if (canvasTransform !== canvas.style.transform) {
canvas.style.transform = canvasTransform;
}
return canvas;
}
/**
* @param {import("../../Tile.js").default} tile Tile.
* @param {import("../../PluggableMap.js").FrameState} frameState Frame state.
* @param {import("../../layer/Layer.js").State} layerState Layer state.
* @param {number} x Left of the tile.
* @param {number} y Top of the tile.
* @param {number} w Width of the tile.
* @param {number} h Height of the tile.
* @param {number} gutter Tile gutter.
* @param {boolean} transition Apply an alpha transition.
*/
drawTileImage(tile, frameState, layerState, x, y, w, h, gutter, transition) {
const image = this.getTileImage(tile);
if (!image) {
return;
}
const uid = getUid(this);
const alpha = transition ? tile.getAlpha(uid, frameState.time) : 1;
const tileLayer = /** @type {import("../../layer/Tile.js").default} */ (this.getLayer());
const tileSource = /** @type {import("../../source/Tile.js").default} */ (tileLayer.getSource());
if (alpha === 1 && !tileSource.getOpaque(frameState.viewState.projection)) {
this.context.clearRect(x, y, w, h);
}
const alphaChanged = alpha !== this.context.globalAlpha;
if (alphaChanged) {
this.context.save();
this.context.globalAlpha = alpha;
}
this.context.drawImage(image, gutter, gutter,
image.width - 2 * gutter, image.height - 2 * gutter, x, y, w, h);
if (alphaChanged) {
this.context.restore();
}
if (alpha !== 1) {
frameState.animate = true;
} else if (transition) {
tile.endTransition(uid);
}
}
/**
* @inheritDoc
*/
getImage() {
const context = this.context;
return context ? context.canvas : null;
}
/**
* Get the image from a tile.
* @param {import("../../Tile.js").default} tile Tile.
* @return {HTMLCanvasElement|HTMLImageElement|HTMLVideoElement} Image.
* @protected
*/
getTileImage(tile) {
return /** @type {import("../../ImageTile.js").default} */ (tile).getImage();
}
}
/**
* @function
* @return {import("../../layer/Tile.js").default|import("../../layer/VectorTile.js").default}
*/
CanvasTileLayerRenderer.prototype.getLayer;
export default CanvasTileLayerRenderer;