@itwin/core-frontend
Version:
iTwin.js frontend components
111 lines • 4.74 kB
JavaScript
/*---------------------------------------------------------------------------------------------
* Copyright (c) Bentley Systems, Incorporated. All rights reserved.
* See LICENSE.md in the project root for license terms and full copyright notice.
*--------------------------------------------------------------------------------------------*/
/** @packageDocumentation
* @module Views
*/
import { assert } from "@itwin/core-bentley";
import { Point2d, Range1d } from "@itwin/core-geometry";
import { Cartographic } from "@itwin/core-common";
import { GeographicTilingScheme } from "./tile/internal";
let instance;
/**
* A collection of functions for approximating terrain height
* @internal
*/
export class ApproximateTerrainHeights {
static maxLevel = 6;
globalHeightRange = Range1d.createXX(-400, 90000); // Dead Sea to Mount Everest.
_terrainHeights;
_scratchCorners = [Cartographic.createZero(), Cartographic.createZero(), Cartographic.createZero(), Cartographic.createZero()];
_tilingScheme = new GeographicTilingScheme(2, 1, true); // Y at top... ?
_scratchTileXY = Point2d.createZero();
static get instance() {
if (undefined === instance)
instance = new ApproximateTerrainHeights();
return instance;
}
/**
* Initializes the minimum and maximum terrain heights.
* @return {Promise}
*/
async initialize() {
if (!this._terrainHeights) {
const { terrainHeightsPropsString } = await import("./ApproximateTerrainHeightsProps");
this._terrainHeights = JSON.parse(terrainHeightsPropsString);
}
}
getTileHeightRange(quadId, result) {
result = Range1d.createFrom(this.globalHeightRange, result);
if (undefined === this._terrainHeights)
return result; // Not initialized.
let level = quadId.level, column = quadId.column, row = quadId.row;
if (level > 6) {
column = column >> (level - 6);
row = row >> quadId.row >> ((level - 6));
level = 6;
}
const key = `${level}-${column}-${row}`;
const heights = this._terrainHeights[key];
assert(undefined !== heights);
result.low = heights[0];
result.high = heights[1];
return result;
}
getMinimumMaximumHeights(rectangle, result) {
result = Range1d.createFrom(this.globalHeightRange, result);
if (undefined === this._terrainHeights)
return result; // Not initialized.
const xyLevel = this._getTileXYLevel(rectangle);
if (undefined !== xyLevel) {
const key = `${xyLevel.level}-${xyLevel.x}-${xyLevel.y}`;
const heights = this._terrainHeights[key];
assert(undefined !== heights);
if (undefined !== heights) {
result.low = heights[0];
result.high = heights[1];
}
}
return result;
}
_getTileXYLevel(rectangle) {
Cartographic.fromRadians({ longitude: rectangle.low.x, latitude: rectangle.high.y, height: 0.0 }, this._scratchCorners[0]);
Cartographic.fromRadians({ longitude: rectangle.high.x, latitude: rectangle.high.y, height: 0.0 }, this._scratchCorners[1]);
Cartographic.fromRadians({ longitude: rectangle.low.x, latitude: rectangle.low.y, height: 0.0 }, this._scratchCorners[2]);
Cartographic.fromRadians({ longitude: rectangle.high.x, latitude: rectangle.low.y, height: 0.0 }, this._scratchCorners[3]);
// Determine which tile the bounding rectangle is in
let lastLevelX = 0, lastLevelY = 0;
let currentX = 0, currentY = 0;
const maxLevel = ApproximateTerrainHeights.maxLevel;
let i;
for (i = 0; i <= maxLevel; ++i) {
let failed = false;
for (let j = 0; j < 4; ++j) {
const corner = this._scratchCorners[j];
this._tilingScheme.cartographicToTileXY(corner, i, this._scratchTileXY);
if (j === 0) {
currentX = this._scratchTileXY.x;
currentY = this._scratchTileXY.y;
}
else if (currentX !== this._scratchTileXY.x || currentY !== this._scratchTileXY.y) {
failed = true;
break;
}
}
if (failed)
break;
lastLevelX = currentX;
lastLevelY = currentY;
}
if (i === 0) {
return undefined;
}
return {
x: lastLevelX,
y: lastLevelY,
level: (i > maxLevel) ? maxLevel : (i - 1),
};
}
}
//# sourceMappingURL=ApproximateTerrainHeights.js.map