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| 1 | +// @class TileLayer |
| 2 | + |
| 3 | +L.TileLayer.mergeOptions({ |
| 4 | + // @option keepBuffer |
| 5 | + // The amount of tiles outside the visible map area to be kept in the stitched |
| 6 | + // `TileLayer`. |
| 7 | + |
| 8 | + // @option dumpToCanvas: Boolean = true |
| 9 | + // Whether to dump loaded tiles to a `<canvas>` to prevent some rendering |
| 10 | + // artifacts. (Disabled by default in IE) |
| 11 | + dumpToCanvas: L.Browser.canvas && !L.Browser.ie, |
| 12 | +}); |
| 13 | + |
| 14 | +L.TileLayer.include({ |
| 15 | + _onUpdateLevel: function(z, zoom) { |
| 16 | + if (this.options.dumpToCanvas) { |
| 17 | + this._levels[z].canvas.style.zIndex = |
| 18 | + this.options.maxZoom - Math.abs(zoom - z); |
| 19 | + } |
| 20 | + }, |
| 21 | + |
| 22 | + _onRemoveLevel: function(z) { |
| 23 | + if (this.options.dumpToCanvas) { |
| 24 | + L.DomUtil.remove(this._levels[z].canvas); |
| 25 | + } |
| 26 | + }, |
| 27 | + |
| 28 | + _onCreateLevel: function(level) { |
| 29 | + if (this.options.dumpToCanvas) { |
| 30 | + level.canvas = L.DomUtil.create( |
| 31 | + "canvas", |
| 32 | + "leaflet-tile-container leaflet-zoom-animated", |
| 33 | + this._container |
| 34 | + ); |
| 35 | + level.ctx = level.canvas.getContext("2d"); |
| 36 | + this._resetCanvasSize(level); |
| 37 | + } |
| 38 | + }, |
| 39 | + |
| 40 | + _removeTile: function(key) { |
| 41 | + if (this.options.dumpToCanvas) { |
| 42 | + var tile = this._tiles[key]; |
| 43 | + var level = this._levels[tile.coords.z]; |
| 44 | + var tileSize = this.getTileSize(); |
| 45 | + |
| 46 | + if (level) { |
| 47 | + // Where in the canvas should this tile go? |
| 48 | + var offset = L.point(tile.coords.x, tile.coords.y) |
| 49 | + .subtract(level.canvasRange.min) |
| 50 | + .scaleBy(this.getTileSize()); |
| 51 | + |
| 52 | + level.ctx.clearRect(offset.x, offset.y, tileSize.x, tileSize.y); |
| 53 | + } |
| 54 | + } |
| 55 | + |
| 56 | + L.GridLayer.prototype._removeTile.call(this, key); |
| 57 | + }, |
| 58 | + |
| 59 | + _resetCanvasSize: function(level) { |
| 60 | + var buff = this.options.keepBuffer, |
| 61 | + pixelBounds = this._getTiledPixelBounds(this._map.getCenter()), |
| 62 | + tileRange = this._pxBoundsToTileRange(pixelBounds), |
| 63 | + tileSize = this.getTileSize(); |
| 64 | + |
| 65 | + tileRange.min = tileRange.min.subtract([buff, buff]); // This adds the no-prune buffer |
| 66 | + tileRange.max = tileRange.max.add([buff + 1, buff + 1]); |
| 67 | + |
| 68 | + var pixelRange = L.bounds( |
| 69 | + tileRange.min.scaleBy(tileSize), |
| 70 | + tileRange.max.add([1, 1]).scaleBy(tileSize) // This prevents an off-by-one when checking if tiles are inside |
| 71 | + ), |
| 72 | + mustRepositionCanvas = false, |
| 73 | + neededSize = pixelRange.max.subtract(pixelRange.min); |
| 74 | + |
| 75 | + // Resize the canvas, if needed, and only to make it bigger. |
| 76 | + if ( |
| 77 | + neededSize.x > level.canvas.width || |
| 78 | + neededSize.y > level.canvas.height |
| 79 | + ) { |
| 80 | + // Resizing canvases erases the currently drawn content, I'm afraid. |
| 81 | + // To keep it, dump the pixels to another canvas, then display it on |
| 82 | + // top. This could be done with getImageData/putImageData, but that |
| 83 | + // would break for tainted canvases (in non-CORS tilesets) |
| 84 | + var oldSize = { x: level.canvas.width, y: level.canvas.height }; |
| 85 | + // console.info('Resizing canvas from ', oldSize, 'to ', neededSize); |
| 86 | + |
| 87 | + var tmpCanvas = L.DomUtil.create("canvas"); |
| 88 | + tmpCanvas.style.width = (tmpCanvas.width = oldSize.x) + "px"; |
| 89 | + tmpCanvas.style.height = (tmpCanvas.height = oldSize.y) + "px"; |
| 90 | + tmpCanvas.getContext("2d").drawImage(level.canvas, 0, 0); |
| 91 | + // var data = level.ctx.getImageData(0, 0, oldSize.x, oldSize.y); |
| 92 | + |
| 93 | + level.canvas.style.width = (level.canvas.width = neededSize.x) + "px"; |
| 94 | + level.canvas.style.height = (level.canvas.height = neededSize.y) + "px"; |
| 95 | + level.ctx.drawImage(tmpCanvas, 0, 0); |
| 96 | + // level.ctx.putImageData(data, 0, 0, 0, 0, oldSize.x, oldSize.y); |
| 97 | + } |
| 98 | + |
| 99 | + // Translate the canvas contents if it's moved around |
| 100 | + if (level.canvasRange) { |
| 101 | + var offset = level.canvasRange.min |
| 102 | + .subtract(tileRange.min) |
| 103 | + .scaleBy(this.getTileSize()); |
| 104 | + |
| 105 | + // console.info('Offsetting by ', offset); |
| 106 | + |
| 107 | + if (!L.Browser.safari) { |
| 108 | + // By default, canvases copy things "on top of" existing pixels, but we want |
| 109 | + // this to *replace* the existing pixels when doing a drawImage() call. |
| 110 | + // This will also clear the sides, so no clearRect() calls are needed to make room |
| 111 | + // for the new tiles. |
| 112 | + level.ctx.globalCompositeOperation = "copy"; |
| 113 | + level.ctx.drawImage(level.canvas, offset.x, offset.y); |
| 114 | + level.ctx.globalCompositeOperation = "source-over"; |
| 115 | + } else { |
| 116 | + // Safari clears the canvas when copying from itself :-( |
| 117 | + if (!this._tmpCanvas) { |
| 118 | + var t = (this._tmpCanvas = L.DomUtil.create("canvas")); |
| 119 | + t.width = level.canvas.width; |
| 120 | + t.height = level.canvas.height; |
| 121 | + this._tmpContext = t.getContext("2d"); |
| 122 | + } |
| 123 | + this._tmpContext.clearRect( |
| 124 | + 0, |
| 125 | + 0, |
| 126 | + level.canvas.width, |
| 127 | + level.canvas.height |
| 128 | + ); |
| 129 | + this._tmpContext.drawImage(level.canvas, 0, 0); |
| 130 | + level.ctx.clearRect(0, 0, level.canvas.width, level.canvas.height); |
| 131 | + level.ctx.drawImage(this._tmpCanvas, offset.x, offset.y); |
| 132 | + } |
| 133 | + |
| 134 | + mustRepositionCanvas = true; // Wait until new props are set |
| 135 | + } |
| 136 | + |
| 137 | + level.canvasRange = tileRange; |
| 138 | + level.canvasPxRange = pixelRange; |
| 139 | + level.canvasOrigin = pixelRange.min; |
| 140 | + |
| 141 | + // console.log('Canvas tile range: ', level, tileRange.min, tileRange.max ); |
| 142 | + // console.log('Canvas pixel range: ', pixelRange.min, pixelRange.max ); |
| 143 | + // console.log('Level origin: ', level.origin ); |
| 144 | + |
| 145 | + if (mustRepositionCanvas) { |
| 146 | + this._setCanvasZoomTransform( |
| 147 | + level, |
| 148 | + this._map.getCenter(), |
| 149 | + this._map.getZoom() |
| 150 | + ); |
| 151 | + } |
| 152 | + }, |
| 153 | + |
| 154 | + /// set transform/position of canvas, in addition to the transform/position of the individual tile container |
| 155 | + _setZoomTransform: function(level, center, zoom) { |
| 156 | + L.GridLayer.prototype._setZoomTransform.call(this, level, center, zoom); |
| 157 | + if (this.options.dumpToCanvas) { |
| 158 | + this._setCanvasZoomTransform(level, center, zoom); |
| 159 | + } |
| 160 | + }, |
| 161 | + |
| 162 | + // This will get called twice: |
| 163 | + // * From _setZoomTransform |
| 164 | + // * When the canvas has shifted due to a new tile being loaded |
| 165 | + _setCanvasZoomTransform: function(level, center, zoom) { |
| 166 | + // console.log('_setCanvasZoomTransform', level, center, zoom); |
| 167 | + if (!level.canvasOrigin) { |
| 168 | + return; |
| 169 | + } |
| 170 | + var scale = this._map.getZoomScale(zoom, level.zoom), |
| 171 | + translate = level.canvasOrigin |
| 172 | + .multiplyBy(scale) |
| 173 | + .subtract(this._map._getNewPixelOrigin(center, zoom)) |
| 174 | + .round(); |
| 175 | + |
| 176 | + if (L.Browser.any3d) { |
| 177 | + L.DomUtil.setTransform(level.canvas, translate, scale); |
| 178 | + } else { |
| 179 | + L.DomUtil.setPosition(level.canvas, translate); |
| 180 | + } |
| 181 | + }, |
| 182 | + |
| 183 | + _onOpaqueTile: function(tile) { |
| 184 | + if (!this.options.dumpToCanvas) { |
| 185 | + return; |
| 186 | + } |
| 187 | + |
| 188 | + // Guard against an NS_ERROR_NOT_AVAILABLE (or similar) exception |
| 189 | + // when a non-image-tile has been loaded (e.g. a WMS error). |
| 190 | + // Checking for tile.el.complete is not enough, as it has been |
| 191 | + // already marked as loaded and ready somehow. |
| 192 | + try { |
| 193 | + this.dumpPixels(tile.coords, tile.el); |
| 194 | + } catch (ex) { |
| 195 | + return this.fire("tileerror", { |
| 196 | + error: "Could not copy tile pixels: " + ex, |
| 197 | + tile: tile, |
| 198 | + coods: tile.coords, |
| 199 | + }); |
| 200 | + } |
| 201 | + |
| 202 | + // If dumping the pixels was successful, then hide the tile. |
| 203 | + // Do not remove the tile itself, as it is needed to check if the whole |
| 204 | + // level (and its canvas) should be removed (via level.el.children.length) |
| 205 | + tile.el.style.display = "none"; |
| 206 | + }, |
| 207 | + |
| 208 | + // @section Extension methods |
| 209 | + // @uninheritable |
| 210 | + |
| 211 | + // @method dumpPixels(coords: Object, imageSource: CanvasImageSource): this |
| 212 | + // Dumps pixels from the given `CanvasImageSource` into the layer, into |
| 213 | + // the space for the tile represented by the `coords` tile coordinates (an object |
| 214 | + // like `{x: Number, y: Number, z: Number}`; the image source must have the |
| 215 | + // same size as the `tileSize` option for the layer. Has no effect if `dumpToCanvas` |
| 216 | + // is `false`. |
| 217 | + dumpPixels: function(coords, imageSource) { |
| 218 | + var level = this._levels[coords.z], |
| 219 | + tileSize = this.getTileSize(); |
| 220 | + |
| 221 | + if (!level.canvasRange || !this.options.dumpToCanvas) { |
| 222 | + return; |
| 223 | + } |
| 224 | + |
| 225 | + // Check if the tile is inside the currently visible map bounds |
| 226 | + // There is a possible race condition when tiles are loaded after they |
| 227 | + // have been panned outside of the map. |
| 228 | + if (!level.canvasRange.contains(coords)) { |
| 229 | + this._resetCanvasSize(level); |
| 230 | + } |
| 231 | + |
| 232 | + // Where in the canvas should this tile go? |
| 233 | + var offset = L.point(coords.x, coords.y) |
| 234 | + .subtract(level.canvasRange.min) |
| 235 | + .scaleBy(this.getTileSize()); |
| 236 | + |
| 237 | + level.ctx.drawImage(imageSource, offset.x, offset.y, tileSize.x, tileSize.y); |
| 238 | + |
| 239 | + // TODO: Clear the pixels of other levels' canvases where they overlap |
| 240 | + // this newly dumped tile. |
| 241 | + return this; |
| 242 | + }, |
| 243 | +}); |
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