How to modify raster tile source to store/track tile sizes (content of raster tile)?

[prusswan]

I managed to extract the logic used by map.showTileBoundaries into a custom layer, only to find out that the information (img/response.data) is not stored for raster tiles:

maplibre-gl-js/src/source/raster_tile_source.ts

Lines 176 to 211 in 2ce959a

	async loadTile(tile: Tile): Promise<void> {
	const url = tile.tileID.canonical.url(this.tiles, this.map.getPixelRatio(), this.scheme);
	tile.abortController = new AbortController();
	try {
	const response = await ImageRequest.getImage(this.map._requestManager.transformRequest(url, ResourceType.Tile), tile.abortController, this.map._refreshExpiredTiles);
	delete tile.abortController;
	if (tile.aborted) {
	tile.state = 'unloaded';
	return;
	}
	if (response && response.data) {
	if (this.map._refreshExpiredTiles && (response.cacheControl || response.expires)) {
	tile.setExpiryData({cacheControl: response.cacheControl, expires: response.expires});
	}
	const context = this.map.painter.context;
	const gl = context.gl;
	const img = response.data;
	tile.texture = this.map.painter.getTileTexture(img.width);
	if (tile.texture) {
	tile.texture.update(img, {useMipmap: true});
	} else {
	tile.texture = new Texture(context, img, gl.RGBA, {useMipmap: true});
	tile.texture.bind(gl.LINEAR, gl.CLAMP_TO_EDGE, gl.LINEAR_MIPMAP_NEAREST);
	}
	tile.state = 'loaded';
	}
	} catch (err) {
	delete tile.abortController;
	if (tile.aborted) {
	tile.state = 'unloaded';
	} else if (err) {
	tile.state = 'errored';
	throw err;
	}
	}
	}

Is there any easy way I could modify the loadTile logic, or pass in a custom version of RasterTileSource?

[HarelM]

IIRC Yes, but it's extremely complicated.
You could create a new type of source and register it, if you need to run things in the worker you need to register the worker code as well, see here:

maplibre-gl-js/src/index.ts

Line 255 in 2ce959a

addSourceType,

[prusswan]

IIRC Yes, but it's extremely complicated. You could create a new type of source and register it, if you need to run things in the worker you need to register the worker code as well, see here:

maplibre-gl-js/src/index.ts

Line 255 in 2ce959a

addSourceType,

Thanks @HarelM, I found #4480 (reply in thread) which was very close to what I needed.

https://jsfiddle.net/prusswan/zq8sr0wp/show

Maybe more of the internal functions can be exposed so it is easier to setup custom layers/sources or modify the default ones.