From 0ce8003879efa98550a8cd977c24e239eedd8d3a Mon Sep 17 00:00:00 2001 From: Tobias Gassmann Date: Thu, 21 Mar 2024 14:47:05 +0100 Subject: [PATCH 1/2] adjust to linter rules --- .../engine/Source/Core/AWSTerrainProvider.js | 171 ++++++++++++++++++ 1 file changed, 171 insertions(+) create mode 100644 packages/engine/Source/Core/AWSTerrainProvider.js diff --git a/packages/engine/Source/Core/AWSTerrainProvider.js b/packages/engine/Source/Core/AWSTerrainProvider.js new file mode 100644 index 000000000000..a59f640546d9 --- /dev/null +++ b/packages/engine/Source/Core/AWSTerrainProvider.js @@ -0,0 +1,171 @@ +import Credit from "./Credit"; +import Ellipsoid from "./Ellipsoid"; +import Event from "./Event"; +import HeightmapTerrainData from "./HeightmapTerrainData"; +import TerrainProvider from "./TerrainProvider"; +import WebMercatorTilingScheme from "./WebMercatorTilingScheme"; + +const ADDRESS = "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/"; +const MAX_LOD = 15; + +function AWSTerrainProvider(options = {}) { + this.targetResolution = options.targetResolution || 32; + + this._tilingScheme = new WebMercatorTilingScheme({ + ellipsoid: Ellipsoid.WGS84, + numberOfLevelZeroTilesX: 1, + numberOfLevelZeroTilesY: 1, + }); + this._readyPromise = Promise.resolve(true); + this._errorEvent = new Event(); + this._credit = new Credit( + 'AWS Open Data Terrain Tiles', + true + ); +} + +AWSTerrainProvider.prototype = Object.create(TerrainProvider.prototype); +AWSTerrainProvider.prototype.constructor = AWSTerrainProvider; + +AWSTerrainProvider.prototype.decodeElevation = function (rgb) { + return rgb[0] * 256 + rgb[1] + rgb[2] / 256 - 32768; +}; + +AWSTerrainProvider.prototype.requestTileGeometry = function ( + x, + y, + level, + request +) { + return this.fetchTile(level, x, y) + .then((image) => { + const offscreenCanvas = new OffscreenCanvas(image.width, image.height); + const context = offscreenCanvas.getContext("2d", { + willReadFrequently: true, + }); + context.imageSmoothingEnabled = false; + context.drawImage(image, 0, 0); + + const imageData = context.getImageData( + 0, + 0, + offscreenCanvas.width, + offscreenCanvas.height + ); + + // Downsampling factor - how many original pixels correspond to one in the downsampled image + const downsampleFactor = imageData.width / this.targetResolution; + const downsampledHeightData = new Float32Array( + this.targetResolution * this.targetResolution + ); + + for (let i = 0; i < this.targetResolution; i++) { + for (let j = 0; j < this.targetResolution; j++) { + // Calculate the index in the original data + const idx = + (i * downsampleFactor * imageData.width + j * downsampleFactor) * 4; + const rgb = [ + imageData.data[idx], + imageData.data[idx + 1], + imageData.data[idx + 2], + ]; + const elevation = this.decodeElevation(rgb); + // Assign the downsampled elevation + downsampledHeightData[i * this.targetResolution + j] = elevation; + } + } + + return new HeightmapTerrainData({ + buffer: downsampledHeightData, + width: this.targetResolution, + height: this.targetResolution, + }); + }) + .catch((error) => { + console.error("Failed to load or decode terrain tile:", error); + return undefined; + }); +}; + +AWSTerrainProvider.prototype.fetchTile = function (zoom, x, y) { + return new Promise((resolve, reject) => { + const image = new Image(); + image.crossOrigin = "anonymous"; + image.onload = () => resolve(image); + image.onerror = (e) => + reject( + new Error( + `Failed to load tile at zoom ${zoom}, x ${x}, y ${y}: ${e.message}` + ) + ); + image.src = `${ADDRESS}${zoom}/${x}/${y}.png`; + }); +}; + +AWSTerrainProvider.prototype.getLevelMaximumGeometricError = function (level) { + const levelZeroError = TerrainProvider.getEstimatedLevelZeroGeometricErrorForAHeightmap( + this._tilingScheme.ellipsoid, + 256 /* tile width */, + this._tilingScheme.getNumberOfXTilesAtLevel(0) + ); + return levelZeroError / (1 << level); +}; + +AWSTerrainProvider.prototype.getTileDataAvailable = function (x, y, level) { + return level <= MAX_LOD; +}; + +AWSTerrainProvider.prototype.loadTileDataAvailability = function (x, y, level) { + if (level > MAX_LOD - 1) { + return Promise.resolve(false); + } + return Promise.resolve(true); +}; + +AWSTerrainProvider.prototype.positionToTileXY = function (position, level) { + return this._tilingScheme.positionToTileXY(position, level); +}; + +Object.defineProperties(AWSTerrainProvider.prototype, { + errorEvent: { + get: function () { + return this._errorEvent; + }, + }, + credit: { + get: function () { + return this._credit; + }, + }, + tilingScheme: { + get: function () { + return this._tilingScheme; + }, + }, + ready: { + get: function () { + return this._readyPromise; + }, + }, + hasWaterMask: { + get: function () { + return false; + }, + }, + hasVertexNormals: { + get: function () { + return false; + }, + }, + availability: { + get: function () { + return { + computeMaximumLevelAtPosition: (position) => { + return MAX_LOD; + }, + }; + }, + }, +}); + +export default AWSTerrainProvider; From 1c517e2db60d10d1c041416526fb719990bba4da Mon Sep 17 00:00:00 2001 From: Tobias Gassmann Date: Fri, 22 Mar 2024 07:54:44 +0100 Subject: [PATCH 2/2] Update CONTRIBUTORS.md --- CONTRIBUTORS.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md index 8e7b4344f1de..a864c8e04a1a 100644 --- a/CONTRIBUTORS.md +++ b/CONTRIBUTORS.md @@ -194,6 +194,8 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute to Cesiu - [T2 Software](http://t2.com.tr/) - [Hüseyin ATEŞ](https://github.com/ateshuseyin) - [İbrahim Furkan Aygar](https://github.com/furkanaygar) +- [tobiga UG (haftungsbeschränkt)](https://tobiga.de/) + - [Tobias Gassmann](https://github.com/tobias74) ## [Individual CLA](Documentation/Contributors/CLAs/individual-contributor-license-agreement-v1.0.pdf)