Remove map tile gap workaround and use NoGap instead

auto_rx/autorx/static/css/main.css

@@ -508,12 +508,6 @@ select[disabled]{
     font-weight: bold;
 }
 
-/* workaround for subpixel lines https://github.com/Leaflet/Leaflet/issues/3575#issuecomment-688644225 */
-.leaflet-tile-container img {
-    width: 256.5px !important;
-    height: 256.5px !important;
-}
-
 /* The slider itself */
 #skewt-decimation {
   -webkit-appearance: none;  /* Override default CSS styles */

auto_rx/autorx/static/js/L.TileLayer.NoGap.js

@@ -0,0 +1,243 @@
+// @class TileLayer
+
+L.TileLayer.mergeOptions({
+	// @option keepBuffer
+	// The amount of tiles outside the visible map area to be kept in the stitched
+	// `TileLayer`.
+
+	// @option dumpToCanvas: Boolean = true
+	// Whether to dump loaded tiles to a `<canvas>` to prevent some rendering
+	// artifacts. (Disabled by default in IE)
+	dumpToCanvas: L.Browser.canvas && !L.Browser.ie,
+});
+
+L.TileLayer.include({
+	_onUpdateLevel: function(z, zoom) {
+		if (this.options.dumpToCanvas) {
+			this._levels[z].canvas.style.zIndex =
+				this.options.maxZoom - Math.abs(zoom - z);
+		}
+	},
+
+	_onRemoveLevel: function(z) {
+		if (this.options.dumpToCanvas) {
+			L.DomUtil.remove(this._levels[z].canvas);
+		}
+	},
+
+	_onCreateLevel: function(level) {
+		if (this.options.dumpToCanvas) {
+			level.canvas = L.DomUtil.create(
+				"canvas",
+				"leaflet-tile-container leaflet-zoom-animated",
+				this._container
+			);
+			level.ctx = level.canvas.getContext("2d");
+			this._resetCanvasSize(level);
+		}
+	},
+
+	_removeTile: function(key) {
+		if (this.options.dumpToCanvas) {
+			var tile = this._tiles[key];
+			var level = this._levels[tile.coords.z];
+			var tileSize = this.getTileSize();
+
+			if (level) {
+				// Where in the canvas should this tile go?
+				var offset = L.point(tile.coords.x, tile.coords.y)
+					.subtract(level.canvasRange.min)
+					.scaleBy(this.getTileSize());
+
+				level.ctx.clearRect(offset.x, offset.y, tileSize.x, tileSize.y);
+			}
+		}
+
+		L.GridLayer.prototype._removeTile.call(this, key);
+	},
+
+	_resetCanvasSize: function(level) {
+		var buff = this.options.keepBuffer,
+			pixelBounds = this._getTiledPixelBounds(this._map.getCenter()),
+			tileRange = this._pxBoundsToTileRange(pixelBounds),
+			tileSize = this.getTileSize();
+
+		tileRange.min = tileRange.min.subtract([buff, buff]); // This adds the no-prune buffer
+		tileRange.max = tileRange.max.add([buff + 1, buff + 1]);
+
+		var pixelRange = L.bounds(
+				tileRange.min.scaleBy(tileSize),
+				tileRange.max.add([1, 1]).scaleBy(tileSize) // This prevents an off-by-one when checking if tiles are inside
+			),
+			mustRepositionCanvas = false,
+			neededSize = pixelRange.max.subtract(pixelRange.min);
+
+		// Resize the canvas, if needed, and only to make it bigger.
+		if (
+			neededSize.x > level.canvas.width ||
+			neededSize.y > level.canvas.height
+		) {
+			// Resizing canvases erases the currently drawn content, I'm afraid.
+			// To keep it, dump the pixels to another canvas, then display it on
+			// top. This could be done with getImageData/putImageData, but that
+			// would break for tainted canvases (in non-CORS tilesets)
+			var oldSize = { x: level.canvas.width, y: level.canvas.height };
+			// console.info('Resizing canvas from ', oldSize, 'to ', neededSize);
+
+			var tmpCanvas = L.DomUtil.create("canvas");
+			tmpCanvas.style.width = (tmpCanvas.width = oldSize.x) + "px";
+			tmpCanvas.style.height = (tmpCanvas.height = oldSize.y) + "px";
+			tmpCanvas.getContext("2d").drawImage(level.canvas, 0, 0);
+			// var data = level.ctx.getImageData(0, 0, oldSize.x, oldSize.y);
+
+			level.canvas.style.width = (level.canvas.width = neededSize.x) + "px";
+			level.canvas.style.height = (level.canvas.height = neededSize.y) + "px";
+			level.ctx.drawImage(tmpCanvas, 0, 0);
+			// level.ctx.putImageData(data, 0, 0, 0, 0, oldSize.x, oldSize.y);
+		}
+
+		// Translate the canvas contents if it's moved around
+		if (level.canvasRange) {
+			var offset = level.canvasRange.min
+				.subtract(tileRange.min)
+				.scaleBy(this.getTileSize());
+
+			// 			console.info('Offsetting by ', offset);
+
+			if (!L.Browser.safari) {
+				// By default, canvases copy things "on top of" existing pixels, but we want
+				// this to *replace* the existing pixels when doing a drawImage() call.
+				// This will also clear the sides, so no clearRect() calls are needed to make room
+				// for the new tiles.
+				level.ctx.globalCompositeOperation = "copy";
+				level.ctx.drawImage(level.canvas, offset.x, offset.y);
+				level.ctx.globalCompositeOperation = "source-over";
+			} else {
+				// Safari clears the canvas when copying from itself :-(
+				if (!this._tmpCanvas) {
+					var t = (this._tmpCanvas = L.DomUtil.create("canvas"));
+					t.width = level.canvas.width;
+					t.height = level.canvas.height;
+					this._tmpContext = t.getContext("2d");
+				}
+				this._tmpContext.clearRect(
+					0,
+					0,
+					level.canvas.width,
+					level.canvas.height
+				);
+				this._tmpContext.drawImage(level.canvas, 0, 0);
+				level.ctx.clearRect(0, 0, level.canvas.width, level.canvas.height);
+				level.ctx.drawImage(this._tmpCanvas, offset.x, offset.y);
+			}
+
+			mustRepositionCanvas = true; // Wait until new props are set
+		}
+
+		level.canvasRange = tileRange;
+		level.canvasPxRange = pixelRange;
+		level.canvasOrigin = pixelRange.min;
+
+		// console.log('Canvas tile range: ', level, tileRange.min, tileRange.max );
+		// console.log('Canvas pixel range: ', pixelRange.min, pixelRange.max );
+		// console.log('Level origin: ', level.origin );
+
+		if (mustRepositionCanvas) {
+			this._setCanvasZoomTransform(
+				level,
+				this._map.getCenter(),
+				this._map.getZoom()
+			);
+		}
+	},
+
+	/// set transform/position of canvas, in addition to the transform/position of the individual tile container
+	_setZoomTransform: function(level, center, zoom) {
+		L.GridLayer.prototype._setZoomTransform.call(this, level, center, zoom);
+		if (this.options.dumpToCanvas) {
+			this._setCanvasZoomTransform(level, center, zoom);
+		}
+	},
+
+	// This will get called twice:
+	// * From _setZoomTransform
+	// * When the canvas has shifted due to a new tile being loaded
+	_setCanvasZoomTransform: function(level, center, zoom) {
+		// console.log('_setCanvasZoomTransform', level, center, zoom);
+		if (!level.canvasOrigin) {
+			return;
+		}
+		var scale = this._map.getZoomScale(zoom, level.zoom),
+			translate = level.canvasOrigin
+				.multiplyBy(scale)
+				.subtract(this._map._getNewPixelOrigin(center, zoom))
+				.round();
+
+		if (L.Browser.any3d) {
+			L.DomUtil.setTransform(level.canvas, translate, scale);
+		} else {
+			L.DomUtil.setPosition(level.canvas, translate);
+		}
+	},
+
+	_onOpaqueTile: function(tile) {
+		if (!this.options.dumpToCanvas) {
+			return;
+		}
+
+		// Guard against an NS_ERROR_NOT_AVAILABLE (or similar) exception
+		// when a non-image-tile has been loaded (e.g. a WMS error).
+		// Checking for tile.el.complete is not enough, as it has been
+		// already marked as loaded and ready somehow.
+		try {
+			this.dumpPixels(tile.coords, tile.el);
+		} catch (ex) {
+			return this.fire("tileerror", {
+				error: "Could not copy tile pixels: " + ex,
+				tile: tile,
+				coods: tile.coords,
+			});
+		}
+
+		// If dumping the pixels was successful, then hide the tile.
+		// Do not remove the tile itself, as it is needed to check if the whole
+		// level (and its canvas) should be removed (via level.el.children.length)
+		tile.el.style.display = "none";
+	},
+
+	// @section Extension methods
+	// @uninheritable
+
+	// @method dumpPixels(coords: Object, imageSource: CanvasImageSource): this
+	// Dumps pixels from the given `CanvasImageSource` into the layer, into
+	// the space for the tile represented by the `coords` tile coordinates (an object
+	// like `{x: Number, y: Number, z: Number}`; the image source must have the
+	// same size as the `tileSize` option for the layer. Has no effect if `dumpToCanvas`
+	// is `false`.
+	dumpPixels: function(coords, imageSource) {
+		var level = this._levels[coords.z],
+			tileSize = this.getTileSize();
+
+		if (!level.canvasRange || !this.options.dumpToCanvas) {
+			return;
+		}
+
+		// Check if the tile is inside the currently visible map bounds
+		// There is a possible race condition when tiles are loaded after they
+		// have been panned outside of the map.
+		if (!level.canvasRange.contains(coords)) {
+			this._resetCanvasSize(level);
+		}
+
+		// Where in the canvas should this tile go?
+		var offset = L.point(coords.x, coords.y)
+			.subtract(level.canvasRange.min)
+			.scaleBy(this.getTileSize());
+
+		level.ctx.drawImage(imageSource, offset.x, offset.y, tileSize.x, tileSize.y);
+
+		// TODO: Clear the pixels of other levels' canvases where they overlap
+		// this newly dumped tile.
+		return this;
+	},
+});

auto_rx/autorx/templates/historical.html

@@ -21,6 +21,7 @@
     <script src="{{ url_for('static', filename='js/leaflet-providers.js') }}"></script>
     <script src="{{ url_for('static', filename='js/Leaflet.fullscreen.min.js') }}"></script>
     <script src="{{ url_for('static', filename='js/leaflet.edgebuffer.js') }}"></script>
+    <script src="{{ url_for('static', filename='js/L.TileLayer.NoGap.js') }}"></script>
     <script src="{{ url_for('static', filename='js/socket.io.min.js') }}"></script>
     <script src="{{ url_for('static', filename='js/d3.3.5.3.min.js') }}" charset="utf-8"></script>
     <script src="{{ url_for('static', filename='js/utils.js') }}"></script>

auto_rx/autorx/templates/index.html

@@ -21,6 +21,7 @@
     <script src="{{ url_for('static', filename='js/leaflet-providers.js') }}"></script>
     <script src="{{ url_for('static', filename='js/Leaflet.fullscreen.min.js') }}"></script>
     <script src="{{ url_for('static', filename='js/leaflet.edgebuffer.js') }}"></script>
+    <script src="{{ url_for('static', filename='js/L.TileLayer.NoGap.js') }}"></script>
     <script src="{{ url_for('static', filename='js/socket.io.min.js') }}"></script>
     <script src="{{ url_for('static', filename='js/scan_chart.js') }}"></script>
     <script src="{{ url_for('static', filename='js/c3.min.js') }}"></script>