Dynamically render subnets and grid lines

public/index.html

@@ -201,7 +201,6 @@
         touchPitch: false,
         style: {
             version: 8,
-            glyphs: "assets/glyphs/{fontstack}/{range}.pbf",
             sources: {},
             layers: []
         },
@@ -213,12 +212,48 @@
     map.painter.context.extTextureFilterAnisotropic = undefined
     map.touchZoomRotate.disableRotation()
 
+    const tileSize = 256
     const tilesDir = "assets/tiles"
     const tilesId = "ipmap-tiles"
     const privateRangesId = "private-ranges"
+    const subnetsId = "subnets"
     const dataP = fetch(`${tilesDir}/tiles.json`, { cache: "no-store" }).then(res => res.json())
     const privateRangePatternP = map.loadImage("assets/private-range-pattern.png")
 
+    const canvas = document.createElement("canvas")
+    const canvasScale = window.devicePixelRatio
+    canvas.width = tileSize * canvasScale
+    canvas.height = tileSize * canvasScale
+    const ctx = canvas.getContext("2d")
+    ctx.scale(canvasScale, canvasScale)
+    ctx.fillStyle = "white"
+    ctx.lineWidth = 3
+    ctx.font = "bold 20px sans-serif"
+    maplibregl.addProtocol(subnetsId, async (params, abortController) => {
+        console.log(params.url)
+        const [z, y, x] = params.url.split("://")[1].split("/")
+        const width = 2 ** z
+        const subnet = 2 * z
+        const hy = Math.floor(0x10000 * (y / width))
+        const hx = Math.floor(0x10000 * (x / width))
+        const text = ipToRange(coordsToHilbert({ x: hx, y: hy }), subnet)
+        const metrics = ctx.measureText(text)
+        const cy = tileSize / 2 + metrics.actualBoundingBoxAscent / 2
+        const cx = tileSize / 2 - metrics.actualBoundingBoxRight / 2
+        ctx.clearRect(0, 0, tileSize, tileSize)
+        ctx.moveTo(0, 0)
+        ctx.lineTo(tileSize, 0)
+        ctx.lineTo(tileSize, tileSize)
+        ctx.lineTo(0, tileSize)
+        ctx.lineTo(0, 0)
+        ctx.strokeStyle = "white"
+        ctx.stroke()
+        ctx.strokeStyle = "black"
+        ctx.strokeText(text, cx, cy)
+        ctx.fillText(text, cx, cy)
+        return { data: await new Promise((res, rej) => canvas.toBlob(b => b.arrayBuffer().then(res))) }
+    })
+
     map.once("style.load", async () => {
         const data = await dataP
         const flatData = Object.entries(data)
@@ -239,7 +274,7 @@
         map.addSource(tilesId, {
             type: "raster",
             tiles: [`${tilesDir}/${curDate}/${curVariant}/${curColormap}/{z}/{y}/{x}.png`],
-            tileSize: 256,
+            tileSize,
             minzoom: 0,
             maxzoom: 8,
         })
@@ -295,99 +330,19 @@
             type: "fill",
             source: privateRangesId,
             paint: {
-                "fill-color": "#0000FF",
                 "fill-pattern": privateRangePatternId
             }
         })
 
-        const zoomLevels = 8
+        map.addSource(subnetsId, {
-        ;[...Array(zoomLevels)].map((_, i) => i + 1).forEach(z => {
+            type: "raster",
-            const labelsId = `subnet-labels-${z}`
+            tiles: [`${subnetsId}://{z}/{y}/{x}`],
-            const width = 2 ** z
+            tileSize,
-            const subnet = 2 * z
-            const moff = 0.5 / width
-            const hoff = Math.floor(0x10000 * moff)
-            map.addSource(labelsId, {
-                type: "geojson",
-                data: {
-                    type: "FeatureCollection",
-                    features: [...Array(width)].flatMap((_, y) => {
-                        const ny = y / width
-                        const my = ny + moff
-                        const hy = Math.floor(0x10000 * ny)
-                        return [...Array(width)].map((_, x) => {
-                            const nx = x / width
-                            const mx = nx + moff
-                            const hx = Math.floor(0x10000 * nx)
-                            return {
-                                type: "Feature",
-                                geometry: {
-                                    type: "Point",
-                                    coordinates: new maplibregl.MercatorCoordinate(mx, my, 0).toLngLat().toArray()
-                                },
-                                properties: {
-                                    name: ipToRange(coordsToHilbert({ x: hx, y: hy }), subnet)
-                                }
-                            }
-                        })
-                    })
-                }
         })
         map.addLayer({
-                id: labelsId,
+            id: subnetsId,
-                type: "symbol",
+            type: "raster",
-                source: labelsId,
+            source: subnetsId,
-                minzoom: Math.max(z - 1.5, 0),
-                ...(z < zoomLevels ? { maxzoom: z - 0.5 } : {}),
-                layout: {
-                    "text-field": "{name}",
-                    "text-font": ["Open Sans Bold"],
-                    "text-size": 22
-                },
-                paint: {
-                    "text-color": "#FFFFFF"
-                }
-            })
-
-            const gridId = `grid-lines-${z}`
-            map.addSource(gridId, {
-                type: "geojson",
-                data: {
-                    type: "FeatureCollection",
-                    features: [...Array(width + 1)].map((_, i) => i / width).flatMap(i => [
-                        {
-                            type: "Feature",
-                            geometry: {
-                                type: "LineString",
-                                coordinates: [
-                                    new maplibregl.MercatorCoordinate(i, 0, 0).toLngLat().toArray(),
-                                    new maplibregl.MercatorCoordinate(i, 1, 0).toLngLat().toArray(),
-                                ]
-                            }
-                        }, {
-                            type: "Feature",
-                            geometry: {
-                                type: "LineString",
-                                coordinates: [
-                                    new maplibregl.MercatorCoordinate(0, i, 0).toLngLat().toArray(),
-                                    new maplibregl.MercatorCoordinate(1, i, 0).toLngLat().toArray(),
-                                ]
-                            }
-                        }
-                    ])
-                }
-            })
-            map.addLayer({
-                id: gridId,
-                type: "line",
-                source: gridId,
-                minzoom: Math.max(z - 1.5, 0),
-                ...(z < zoomLevels ? { maxzoom: z - 0.5 } : {}),
-                paint: {
-                    "line-color": "#FFFFFF",
-                    "line-width": 3
-                }
-            })
         })
 
         const setStyle = (date, variant, colormap) => {