mapbox-gl
Version:
A WebGL interactive maps library
1,251 lines (1,080 loc) • 71.9 kB
JavaScript
// @flow
import LngLat from './lng_lat.js';
import LngLatBounds from './lng_lat_bounds.js';
import MercatorCoordinate, {mercatorXfromLng, mercatorYfromLat, mercatorZfromAltitude, latFromMercatorY} from './mercator_coordinate.js';
import Point from '@mapbox/point-geometry';
import {wrap, clamp, radToDeg, degToRad, getAABBPointSquareDist, furthestTileCorner} from '../util/util.js';
import {number as interpolate} from '../style-spec/util/interpolate.js';
import EXTENT from '../data/extent.js';
import {vec4, mat4, mat2, vec3, quat} from 'gl-matrix';
import {Aabb, Frustum, Ray} from '../util/primitives.js';
import EdgeInsets from './edge_insets.js';
import {FreeCamera, FreeCameraOptions, orientationFromFrame} from '../ui/free_camera.js';
import assert from 'assert';
import {UnwrappedTileID, OverscaledTileID, CanonicalTileID} from '../source/tile_id.js';
import type {Elevation} from '../terrain/elevation.js';
import type {PaddingOptions} from './edge_insets.js';
const NUM_WORLD_COPIES = 3;
const DEFAULT_MIN_ZOOM = 0;
type RayIntersectionResult = { p0: vec4, p1: vec4, t: number};
type ElevationReference = "sea" | "ground";
/**
* A single transform, generally used for a single tile to be
* scaled, rotated, and zoomed.
* @private
*/
class Transform {
tileSize: number;
tileZoom: number;
lngRange: ?[number, number];
latRange: ?[number, number];
maxValidLatitude: number;
scale: number;
width: number;
height: number;
angle: number;
rotationMatrix: Float64Array;
zoomFraction: number;
pixelsToGLUnits: [number, number];
cameraToCenterDistance: number;
mercatorMatrix: Array<number>;
mercatorFogMatrix: Array<number>;
projMatrix: Float64Array;
invProjMatrix: Float64Array;
alignedProjMatrix: Float64Array;
pixelMatrix: Float64Array;
pixelMatrixInverse: Float64Array;
worldToFogMatrix: Float64Array;
skyboxMatrix: Float32Array;
glCoordMatrix: Float32Array;
labelPlaneMatrix: Float32Array;
freezeTileCoverage: boolean;
cameraElevationReference: ElevationReference;
fogCullDistSq: ?number;
_averageElevation: number;
_elevation: ?Elevation;
_fov: number;
_pitch: number;
_zoom: number;
_cameraZoom: ?number;
_unmodified: boolean;
_renderWorldCopies: boolean;
_minZoom: number;
_maxZoom: number;
_minPitch: number;
_maxPitch: number;
_center: LngLat;
_edgeInsets: EdgeInsets;
_constraining: boolean;
_projMatrixCache: {[_: number]: Float32Array};
_alignedProjMatrixCache: {[_: number]: Float32Array};
_fogTileMatrixCache: {[_: number]: Float32Array};
_camera: FreeCamera;
_centerAltitude: number;
_horizonShift: number;
constructor(minZoom: ?number, maxZoom: ?number, minPitch: ?number, maxPitch: ?number, renderWorldCopies: boolean | void) {
this.tileSize = 512; // constant
this.maxValidLatitude = 85.051129; // constant
this._renderWorldCopies = renderWorldCopies === undefined ? true : renderWorldCopies;
this._minZoom = minZoom || DEFAULT_MIN_ZOOM;
this._maxZoom = maxZoom || 22;
this._minPitch = (minPitch === undefined || minPitch === null) ? 0 : minPitch;
this._maxPitch = (maxPitch === undefined || maxPitch === null) ? 60 : maxPitch;
this.setMaxBounds();
this.width = 0;
this.height = 0;
this._center = new LngLat(0, 0);
this.zoom = 0;
this.angle = 0;
this._fov = 0.6435011087932844;
this._pitch = 0;
this._unmodified = true;
this._edgeInsets = new EdgeInsets();
this._projMatrixCache = {};
this._alignedProjMatrixCache = {};
this._fogTileMatrixCache = {};
this._camera = new FreeCamera();
this._centerAltitude = 0;
this._averageElevation = 0;
this.cameraElevationReference = "ground";
// Move the horizon closer to the center. 0 would not shift the horizon. 1 would put the horizon at the center.
this._horizonShift = 0.1;
}
clone(): Transform {
const clone = new Transform(this._minZoom, this._maxZoom, this._minPitch, this.maxPitch, this._renderWorldCopies);
clone._elevation = this._elevation;
clone._centerAltitude = this._centerAltitude;
clone.tileSize = this.tileSize;
clone.latRange = this.latRange;
clone.width = this.width;
clone.height = this.height;
clone.cameraElevationReference = this.cameraElevationReference;
clone._center = this._center;
clone._setZoom(this.zoom);
clone._cameraZoom = this._cameraZoom;
clone.angle = this.angle;
clone._fov = this._fov;
clone._pitch = this._pitch;
clone._averageElevation = this._averageElevation;
clone._unmodified = this._unmodified;
clone._edgeInsets = this._edgeInsets.clone();
clone._camera = this._camera.clone();
clone._calcMatrices();
clone.freezeTileCoverage = this.freezeTileCoverage;
return clone;
}
get elevation(): ?Elevation { return this._elevation; }
set elevation(elevation: ?Elevation) {
if (this._elevation === elevation) return;
this._elevation = elevation;
if (!elevation) {
this._cameraZoom = null;
this._centerAltitude = 0;
} else {
if (this._updateCenterElevation())
this._updateCameraOnTerrain();
}
this._calcMatrices();
}
updateElevation(constrainCameraOverTerrain: boolean) { // On render, no need for higher granularity on update reasons.
if (this._terrainEnabled() && this._cameraZoom == null) {
if (this._updateCenterElevation())
this._updateCameraOnTerrain();
}
if (constrainCameraOverTerrain) {
this._constrainCameraAltitude();
}
this._calcMatrices();
}
get minZoom(): number { return this._minZoom; }
set minZoom(zoom: number) {
if (this._minZoom === zoom) return;
this._minZoom = zoom;
this.zoom = Math.max(this.zoom, zoom);
}
get maxZoom(): number { return this._maxZoom; }
set maxZoom(zoom: number) {
if (this._maxZoom === zoom) return;
this._maxZoom = zoom;
this.zoom = Math.min(this.zoom, zoom);
}
get minPitch(): number { return this._minPitch; }
set minPitch(pitch: number) {
if (this._minPitch === pitch) return;
this._minPitch = pitch;
this.pitch = Math.max(this.pitch, pitch);
}
get maxPitch(): number { return this._maxPitch; }
set maxPitch(pitch: number) {
if (this._maxPitch === pitch) return;
this._maxPitch = pitch;
this.pitch = Math.min(this.pitch, pitch);
}
get renderWorldCopies(): boolean { return this._renderWorldCopies; }
set renderWorldCopies(renderWorldCopies?: ?boolean) {
if (renderWorldCopies === undefined) {
renderWorldCopies = true;
} else if (renderWorldCopies === null) {
renderWorldCopies = false;
}
this._renderWorldCopies = renderWorldCopies;
}
get worldSize(): number {
return this.tileSize * this.scale;
}
get cameraWorldSize(): number {
const distance = Math.max(this._camera.getDistanceToElevation(this._averageElevation), Number.EPSILON);
return this._worldSizeFromZoom(this._zoomFromMercatorZ(distance));
}
get pixelsPerMeter(): number {
return mercatorZfromAltitude(1, this.center.lat) * this.worldSize;
}
get cameraPixelsPerMeter(): number {
return mercatorZfromAltitude(1, this.center.lat) * this.cameraWorldSize;
}
get centerOffset(): Point {
return this.centerPoint._sub(this.size._div(2));
}
get size(): Point {
return new Point(this.width, this.height);
}
get bearing(): number {
return -this.angle / Math.PI * 180;
}
set bearing(bearing: number) {
const b = -wrap(bearing, -180, 180) * Math.PI / 180;
if (this.angle === b) return;
this._unmodified = false;
this.angle = b;
this._calcMatrices();
// 2x2 matrix for rotating points
this.rotationMatrix = mat2.create();
mat2.rotate(this.rotationMatrix, this.rotationMatrix, this.angle);
}
get pitch(): number {
return this._pitch / Math.PI * 180;
}
set pitch(pitch: number) {
const p = clamp(pitch, this.minPitch, this.maxPitch) / 180 * Math.PI;
if (this._pitch === p) return;
this._unmodified = false;
this._pitch = p;
this._calcMatrices();
}
get fov(): number {
return this._fov / Math.PI * 180;
}
set fov(fov: number) {
fov = Math.max(0.01, Math.min(60, fov));
if (this._fov === fov) return;
this._unmodified = false;
this._fov = fov / 180 * Math.PI;
this._calcMatrices();
}
get averageElevation(): number {
return this._averageElevation;
}
set averageElevation(averageElevation: number) {
this._averageElevation = averageElevation;
this._calcFogMatrices();
}
get zoom(): number { return this._zoom; }
set zoom(zoom: number) {
const z = Math.min(Math.max(zoom, this.minZoom), this.maxZoom);
if (this._zoom === z) return;
this._unmodified = false;
this._setZoom(z);
if (this._terrainEnabled()) {
this._updateCameraOnTerrain();
}
this._constrain();
this._calcMatrices();
}
_setZoom(z: number) {
this._zoom = z;
this.scale = this.zoomScale(z);
this.tileZoom = Math.floor(z);
this.zoomFraction = z - this.tileZoom;
}
_updateCenterElevation(): boolean {
if (!this._elevation)
return false;
// Camera zoom describes the distance of the camera to the sea level (altitude). It is used only for manipulating the camera location.
// The standard zoom (this._zoom) defines the camera distance to the terrain (height). Its behavior and conceptual meaning in determining
// which tiles to stream is same with or without the terrain.
const elevationAtCenter = this._elevation.getAtPointOrZero(MercatorCoordinate.fromLngLat(this.center), -1);
if (elevationAtCenter === -1) {
// Elevation data not loaded yet
this._cameraZoom = null;
return false;
}
this._centerAltitude = elevationAtCenter;
return true;
}
// Places the camera above terrain so that the current zoom value is respected at the center.
// In other words, camera height in relative to ground elevation remains constant.
// Returns false if the elevation data is not available (yet) at the center point.
_updateCameraOnTerrain() {
const height = this.cameraToCenterDistance / this.worldSize;
const terrainElevation = mercatorZfromAltitude(this._centerAltitude, this.center.lat);
this._cameraZoom = this._zoomFromMercatorZ(terrainElevation + height);
}
sampleAverageElevation(): number {
if (!this._elevation) return 0;
const elevation: Elevation = this._elevation;
const elevationSamplePoints = [
[0.5, 0.2],
[0.3, 0.5],
[0.5, 0.5],
[0.7, 0.5],
[0.5, 0.8]
];
const horizon = this.horizonLineFromTop();
let elevationSum = 0.0;
let weightSum = 0.0;
for (let i = 0; i < elevationSamplePoints.length; i++) {
const pt = new Point(
elevationSamplePoints[i][0] * this.width,
horizon + elevationSamplePoints[i][1] * (this.height - horizon)
);
const hit = elevation.pointCoordinate(pt);
if (!hit) continue;
const distanceToHit = Math.hypot(hit[0] - this._camera.position[0], hit[1] - this._camera.position[1]);
const weight = 1 / distanceToHit;
elevationSum += hit[3] * weight;
weightSum += weight;
}
if (weightSum === 0) return NaN;
return elevationSum / weightSum;
}
get center(): LngLat { return this._center; }
set center(center: LngLat) {
if (center.lat === this._center.lat && center.lng === this._center.lng) return;
this._unmodified = false;
this._center = center;
if (this._terrainEnabled()) {
if (this.cameraElevationReference === "ground") {
// Check that the elevation data is available at the new location.
if (this._updateCenterElevation())
this._updateCameraOnTerrain();
else
this._cameraZoom = null;
} else {
this._updateZoomFromElevation();
}
}
this._constrain();
this._calcMatrices();
}
_updateZoomFromElevation() {
if (this._cameraZoom == null || !this._elevation)
return;
// Compute zoom level from the height of the camera relative to the terrain
const cameraZoom: number = this._cameraZoom;
const elevationAtCenter = this._elevation.getAtPointOrZero(MercatorCoordinate.fromLngLat(this.center));
const mercatorElevation = mercatorZfromAltitude(elevationAtCenter, this.center.lat);
const altitude = this._mercatorZfromZoom(cameraZoom);
const minHeight = this._mercatorZfromZoom(this._maxZoom);
const height = Math.max(altitude - mercatorElevation, minHeight);
this._setZoom(this._zoomFromMercatorZ(height));
}
get padding(): PaddingOptions { return this._edgeInsets.toJSON(); }
set padding(padding: PaddingOptions) {
if (this._edgeInsets.equals(padding)) return;
this._unmodified = false;
//Update edge-insets inplace
this._edgeInsets.interpolate(this._edgeInsets, padding, 1);
this._calcMatrices();
}
/**
* Computes a zoom value relative to a map plane that goes through the provided mercator position.
* @param {MercatorCoordinate} position A position defining the altitude of the the map plane.
* @returns {number} The zoom value.
*/
computeZoomRelativeTo(position: MercatorCoordinate): number {
// Find map center position on the target plane by casting a ray from screen center towards the plane.
// Direct distance to the target position is used if the target position is above camera position.
const centerOnTargetAltitude = this.rayIntersectionCoordinate(this.pointRayIntersection(this.centerPoint, position.toAltitude()));
let targetPosition: ?vec3;
if (position.z < this._camera.position[2]) {
targetPosition = [centerOnTargetAltitude.x, centerOnTargetAltitude.y, centerOnTargetAltitude.z];
} else {
targetPosition = [position.x, position.y, position.z];
}
const distToTarget = vec3.length(vec3.sub([], this._camera.position, targetPosition));
return clamp(this._zoomFromMercatorZ(distToTarget), this._minZoom, this._maxZoom);
}
setFreeCameraOptions(options: FreeCameraOptions) {
if (!this.height)
return;
if (!options.position && !options.orientation)
return;
// Camera state must be up-to-date before accessing its getters
this._updateCameraState();
let changed = false;
if (options.orientation && !quat.exactEquals(options.orientation, this._camera.orientation)) {
changed = this._setCameraOrientation(options.orientation);
}
if (options.position) {
const newPosition = [options.position.x, options.position.y, options.position.z];
if (!vec3.exactEquals(newPosition, this._camera.position)) {
this._setCameraPosition(newPosition);
changed = true;
}
}
if (changed) {
this._updateStateFromCamera();
this.recenterOnTerrain();
}
}
getFreeCameraOptions(): FreeCameraOptions {
this._updateCameraState();
const pos = this._camera.position;
const options = new FreeCameraOptions();
options.position = new MercatorCoordinate(pos[0], pos[1], pos[2]);
options.orientation = this._camera.orientation;
options._elevation = this.elevation;
options._renderWorldCopies = this._renderWorldCopies;
return options;
}
_setCameraOrientation(orientation: quat): boolean {
// zero-length quaternions are not valid
if (!quat.length(orientation))
return false;
quat.normalize(orientation, orientation);
// The new orientation must be sanitized by making sure it can be represented
// with a pitch and bearing. Roll-component must be removed and the camera can't be upside down
const forward = vec3.transformQuat([], [0, 0, -1], orientation);
const up = vec3.transformQuat([], [0, -1, 0], orientation);
if (up[2] < 0.0)
return false;
const updatedOrientation = orientationFromFrame(forward, up);
if (!updatedOrientation)
return false;
this._camera.orientation = updatedOrientation;
return true;
}
_setCameraPosition(position: vec3) {
// Altitude must be clamped to respect min and max zoom
const minWorldSize = this.zoomScale(this.minZoom) * this.tileSize;
const maxWorldSize = this.zoomScale(this.maxZoom) * this.tileSize;
const distToCenter = this.cameraToCenterDistance;
position[2] = clamp(position[2], distToCenter / maxWorldSize, distToCenter / minWorldSize);
this._camera.position = position;
}
/**
* The center of the screen in pixels with the top-left corner being (0,0)
* and +y axis pointing downwards. This accounts for padding.
*
* @readonly
* @type {Point}
* @memberof Transform
*/
get centerPoint(): Point {
return this._edgeInsets.getCenter(this.width, this.height);
}
/**
* Returns the vertical half-fov, accounting for padding, in radians.
*
* @readonly
* @type {number}
* @private
*/
get fovAboveCenter(): number {
return this._fov * (0.5 + this.centerOffset.y / this.height);
}
/**
* Returns true if the padding options are equal.
*
* @param {PaddingOptions} padding The padding options to compare.
* @returns {boolean} True if the padding options are equal.
* @memberof Transform
*/
isPaddingEqual(padding: PaddingOptions): boolean {
return this._edgeInsets.equals(padding);
}
/**
* Helper method to update edge-insets inplace.
*
* @param {PaddingOptions} start The initial padding options.
* @param {PaddingOptions} target The target padding options.
* @param {number} t The interpolation variable.
* @memberof Transform
*/
interpolatePadding(start: PaddingOptions, target: PaddingOptions, t: number) {
this._unmodified = false;
this._edgeInsets.interpolate(start, target, t);
this._constrain();
this._calcMatrices();
}
/**
* Return a zoom level that will cover all tiles the transform
* @param {Object} options options
* @param {number} options.tileSize Tile size, expressed in screen pixels.
* @param {boolean} options.roundZoom Target zoom level. If true, the value will be rounded to the closest integer. Otherwise the value will be floored.
* @returns {number} zoom level An integer zoom level at which all tiles will be visible.
*/
coveringZoomLevel(options: {roundZoom?: boolean, tileSize: number}) {
const z = (options.roundZoom ? Math.round : Math.floor)(
this.zoom + this.scaleZoom(this.tileSize / options.tileSize)
);
// At negative zoom levels load tiles from z0 because negative tile zoom levels don't exist.
return Math.max(0, z);
}
/**
* Return any "wrapped" copies of a given tile coordinate that are visible
* in the current view.
*
* @private
*/
getVisibleUnwrappedCoordinates(tileID: CanonicalTileID) {
const result = [new UnwrappedTileID(0, tileID)];
if (this._renderWorldCopies) {
const utl = this.pointCoordinate(new Point(0, 0));
const utr = this.pointCoordinate(new Point(this.width, 0));
const ubl = this.pointCoordinate(new Point(this.width, this.height));
const ubr = this.pointCoordinate(new Point(0, this.height));
const w0 = Math.floor(Math.min(utl.x, utr.x, ubl.x, ubr.x));
const w1 = Math.floor(Math.max(utl.x, utr.x, ubl.x, ubr.x));
// Add an extra copy of the world on each side to properly render ImageSources and CanvasSources.
// Both sources draw outside the tile boundaries of the tile that "contains them" so we need
// to add extra copies on both sides in case offscreen tiles need to draw into on-screen ones.
const extraWorldCopy = 1;
for (let w = w0 - extraWorldCopy; w <= w1 + extraWorldCopy; w++) {
if (w === 0) continue;
result.push(new UnwrappedTileID(w, tileID));
}
}
return result;
}
/**
* Return all coordinates that could cover this transform for a covering
* zoom level.
* @param {Object} options
* @param {number} options.tileSize
* @param {number} options.minzoom
* @param {number} options.maxzoom
* @param {boolean} options.roundZoom
* @param {boolean} options.reparseOverscaled
* @returns {Array<OverscaledTileID>} OverscaledTileIDs
* @private
*/
coveringTiles(
options: {
tileSize: number,
minzoom?: number,
maxzoom?: number,
roundZoom?: boolean,
reparseOverscaled?: boolean,
renderWorldCopies?: boolean,
isTerrainDEM?: boolean
}
): Array<OverscaledTileID> {
let z = this.coveringZoomLevel(options);
const actualZ = z;
const useElevationData = this.elevation && !options.isTerrainDEM;
if (options.minzoom !== undefined && z < options.minzoom) return [];
if (options.maxzoom !== undefined && z > options.maxzoom) z = options.maxzoom;
const centerCoord = MercatorCoordinate.fromLngLat(this.center);
const numTiles = 1 << z;
const centerPoint = [numTiles * centerCoord.x, numTiles * centerCoord.y, 0];
const cameraFrustum = Frustum.fromInvProjectionMatrix(this.invProjMatrix, this.worldSize, z);
const cameraCoord = this.pointCoordinate(this.getCameraPoint());
const meterToTile = numTiles * mercatorZfromAltitude(1, this.center.lat);
const cameraAltitude = this._camera.position[2] / mercatorZfromAltitude(1, this.center.lat);
const cameraPoint = [numTiles * cameraCoord.x, numTiles * cameraCoord.y, cameraAltitude];
// Let's consider an example for !roundZoom: e.g. tileZoom 16 is used from zoom 16 all the way to zoom 16.99.
// This would mean that the minimal distance to split would be based on distance from camera to center of 16.99 zoom.
// The same is already incorporated in logic behind roundZoom for raster (so there is no adjustment needed in following line).
// 0.02 added to compensate for precision errors, see "coveringTiles for terrain" test in transform.test.js.
const zoomSplitDistance = this.cameraToCenterDistance / options.tileSize * (options.roundZoom ? 1 : 0.502);
// No change of LOD behavior for pitch lower than 60 and when there is no top padding: return only tile ids from the requested zoom level
const minZoom = this.pitch <= 60.0 && this._edgeInsets.top <= this._edgeInsets.bottom && !this._elevation ? z : 0;
// When calculating tile cover for terrain, create deep AABB for nodes, to ensure they intersect frustum: for sources,
// other than DEM, use minimum of visible DEM tiles and center altitude as upper bound (pitch is always less than 90°).
const maxRange = options.isTerrainDEM && this._elevation ? this._elevation.exaggeration() * 10000 : this._centerAltitude;
const minRange = options.isTerrainDEM ? -maxRange : this._elevation ? this._elevation.getMinElevationBelowMSL() : 0;
const newRootTile = (wrap: number): any => {
const max = maxRange;
const min = minRange;
return {
// With elevation, this._elevation provides z coordinate values. For 2D:
// All tiles are on zero elevation plane => z difference is zero
aabb: new Aabb([wrap * numTiles, 0, min], [(wrap + 1) * numTiles, numTiles, max]),
zoom: 0,
x: 0,
y: 0,
wrap,
fullyVisible: false
};
};
// Do a depth-first traversal to find visible tiles and proper levels of detail
const stack = [];
const result = [];
const maxZoom = z;
const overscaledZ = options.reparseOverscaled ? actualZ : z;
const getAABBFromElevation = (it) => {
assert(this._elevation);
if (!this._elevation || !it.tileID) return; // To silence flow.
const minmax = this._elevation.getMinMaxForTile(it.tileID);
const aabb = it.aabb;
if (minmax) {
aabb.min[2] = minmax.min;
aabb.max[2] = minmax.max;
aabb.center[2] = (aabb.min[2] + aabb.max[2]) / 2;
} else {
it.shouldSplit = shouldSplit(it);
if (!it.shouldSplit) {
// At final zoom level, while corresponding DEM tile is not loaded yet,
// assume center elevation. This covers ground to horizon and prevents
// loading unnecessary tiles until DEM cover is fully loaded.
aabb.min[2] = aabb.max[2] = aabb.center[2] = this._centerAltitude;
}
}
};
const square = a => a * a;
const cameraHeightSqr = square((cameraAltitude - this._centerAltitude) * meterToTile); // in tile coordinates.
// Scale distance to split for acute angles.
// dzSqr: z component of camera to tile distance, square.
// dSqr: 3D distance of camera to tile, square.
const distToSplitScale = (dzSqr, dSqr) => {
// When the angle between camera to tile ray and tile plane is smaller
// than acuteAngleThreshold, scale the distance to split. Scaling is adaptive: smaller
// the angle, the scale gets lower value. Although it seems early to start at 45,
// it is not: scaling kicks in around 60 degrees pitch.
const acuteAngleThresholdSin = 0.707; // Math.sin(45)
const stretchTile = 1.1;
// Distances longer than 'dz / acuteAngleThresholdSin' gets scaled
// following geometric series sum: every next dz length in distance can be
// 'stretchTile times' longer. It is further, the angle is sharper. Total,
// adjusted, distance would then be:
// = dz / acuteAngleThresholdSin + (dz * stretchTile + dz * stretchTile ^ 2 + ... + dz * stretchTile ^ k),
// where k = (d - dz / acuteAngleThresholdSin) / dz = d / dz - 1 / acuteAngleThresholdSin;
// = dz / acuteAngleThresholdSin + dz * ((stretchTile ^ (k + 1) - 1) / (stretchTile - 1) - 1)
// or put differently, given that k is based on d and dz, tile on distance d could be used on distance scaled by:
// 1 / acuteAngleThresholdSin + (stretchTile ^ (k + 1) - 1) / (stretchTile - 1) - 1
if (dSqr * square(acuteAngleThresholdSin) < dzSqr) return 1.0; // Early return, no scale.
const r = Math.sqrt(dSqr / dzSqr);
const k = r - 1 / acuteAngleThresholdSin;
return r / (1 / acuteAngleThresholdSin + (Math.pow(stretchTile, k + 1) - 1) / (stretchTile - 1) - 1);
};
const shouldSplit = (it) => {
if (it.zoom < minZoom) {
return true;
} else if (it.zoom === maxZoom) {
return false;
}
if (it.shouldSplit != null) {
return it.shouldSplit;
}
const dx = it.aabb.distanceX(cameraPoint);
const dy = it.aabb.distanceY(cameraPoint);
let dzSqr = cameraHeightSqr;
if (useElevationData) {
dzSqr = square(it.aabb.distanceZ(cameraPoint) * meterToTile);
}
const distanceSqr = dx * dx + dy * dy + dzSqr;
const distToSplit = (1 << maxZoom - it.zoom) * zoomSplitDistance;
const distToSplitSqr = square(distToSplit * distToSplitScale(Math.max(dzSqr, cameraHeightSqr), distanceSqr));
return distanceSqr < distToSplitSqr;
};
if (this._renderWorldCopies) {
// Render copy of the globe thrice on both sides
for (let i = 1; i <= NUM_WORLD_COPIES; i++) {
stack.push(newRootTile(-i));
stack.push(newRootTile(i));
}
}
stack.push(newRootTile(0));
while (stack.length > 0) {
const it = stack.pop();
const x = it.x;
const y = it.y;
let fullyVisible = it.fullyVisible;
// Visibility of a tile is not required if any of its ancestor if fully inside the frustum
if (!fullyVisible) {
const intersectResult = it.aabb.intersects(cameraFrustum);
if (intersectResult === 0)
continue;
fullyVisible = intersectResult === 2;
}
// Have we reached the target depth or is the tile too far away to be any split further?
if (it.zoom === maxZoom || !shouldSplit(it)) {
const tileZoom = it.zoom === maxZoom ? overscaledZ : it.zoom;
if (!!options.minzoom && options.minzoom > tileZoom) {
// Not within source tile range.
continue;
}
const dx = centerPoint[0] - ((0.5 + x + (it.wrap << it.zoom)) * (1 << (z - it.zoom)));
const dy = centerPoint[1] - 0.5 - y;
const id = it.tileID ? it.tileID : new OverscaledTileID(tileZoom, it.wrap, it.zoom, x, y);
result.push({tileID: id, distanceSq: dx * dx + dy * dy});
continue;
}
for (let i = 0; i < 4; i++) {
const childX = (x << 1) + (i % 2);
const childY = (y << 1) + (i >> 1);
const aabb = it.aabb.quadrant(i);
const child = {aabb, zoom: it.zoom + 1, x: childX, y: childY, wrap: it.wrap, fullyVisible, tileID: undefined, shouldSplit: undefined};
if (useElevationData) {
child.tileID = new OverscaledTileID(it.zoom + 1 === maxZoom ? overscaledZ : it.zoom + 1, it.wrap, it.zoom + 1, childX, childY);
getAABBFromElevation(child);
}
stack.push(child);
}
}
if (this.fogCullDistSq) {
const fogCullDistSq = this.fogCullDistSq;
result.splice(0, result.length, ...result.filter(entry => {
const min = [0, 0, 0, 1];
const max = [EXTENT, EXTENT, 0, 1];
const fogTileMatrix = this.calculateFogTileMatrix(entry.tileID.toUnwrapped());
vec4.transformMat4(min, min, fogTileMatrix);
vec4.transformMat4(max, max, fogTileMatrix);
const sqDist = getAABBPointSquareDist(min, max);
if (sqDist === 0) { return true; }
let overHorizonLine = false;
const horizonLineFromTop = this.horizonLineFromTop();
if (sqDist > fogCullDistSq && horizonLineFromTop !== 0) {
const projMatrix = this.calculateProjMatrix(entry.tileID.toUnwrapped());
let minmax;
if (useElevationData && this._elevation) {
minmax = this._elevation.getMinMaxForTile(entry.tileID);
}
if (!minmax) { minmax = {min: minRange, max: maxRange}; }
const cornerFar = furthestTileCorner(this.bearing);
const farX = cornerFar[0] * EXTENT;
const farY = cornerFar[1] * EXTENT;
const worldFar = [farX, farY, minmax.max];
// World to NDC
vec3.transformMat4(worldFar, worldFar, projMatrix);
// NDC to Screen
const screenCoordY = (1 - worldFar[1]) * this.height * 0.5;
// Prevent cutting tiles crossing over the horizon lines to
// prevent pop-in and out within the fog culling range
overHorizonLine = screenCoordY < horizonLineFromTop;
}
return sqDist < fogCullDistSq || overHorizonLine;
}));
}
const cover = result.sort((a, b) => a.distanceSq - b.distanceSq).map(a => a.tileID);
// Relax the assertion on terrain, on high zoom we use distance to center of tile
// while camera might be closer to selected center of map.
assert(!cover.length || this.elevation || cover[0].overscaledZ === overscaledZ);
return cover;
}
resize(width: number, height: number) {
this.width = width;
this.height = height;
this.pixelsToGLUnits = [2 / width, -2 / height];
this._constrain();
this._calcMatrices();
}
get unmodified(): boolean { return this._unmodified; }
zoomScale(zoom: number) { return Math.pow(2, zoom); }
scaleZoom(scale: number) { return Math.log(scale) / Math.LN2; }
project(lnglat: LngLat) {
const lat = clamp(lnglat.lat, -this.maxValidLatitude, this.maxValidLatitude);
return new Point(
mercatorXfromLng(lnglat.lng) * this.worldSize,
mercatorYfromLat(lat) * this.worldSize);
}
unproject(point: Point): LngLat {
return new MercatorCoordinate(point.x / this.worldSize, point.y / this.worldSize).toLngLat();
}
get point(): Point { return this.project(this.center); }
setLocationAtPoint(lnglat: LngLat, point: Point) {
const a = this.pointCoordinate(point);
const b = this.pointCoordinate(this.centerPoint);
const loc = this.locationCoordinate(lnglat);
const newCenter = new MercatorCoordinate(
loc.x - (a.x - b.x),
loc.y - (a.y - b.y));
this.center = this.coordinateLocation(newCenter);
if (this._renderWorldCopies) {
this.center = this.center.wrap();
}
}
setLocation(location: MercatorCoordinate) {
this.center = this.coordinateLocation(location);
if (this._renderWorldCopies) {
this.center = this.center.wrap();
}
}
/**
* Given a location, return the screen point that corresponds to it. In 3D mode
* (with terrain) this behaves the same as in 2D mode.
* This method is coupled with {@see pointLocation} in 3D mode to model map manipulation
* using flat plane approach to keep constant elevation above ground.
* @param {LngLat} lnglat location
* @returns {Point} screen point
* @private
*/
locationPoint(lnglat: LngLat) {
return this._coordinatePoint(this.locationCoordinate(lnglat), false);
}
/**
* Given a location, return the screen point that corresponds to it
* In 3D mode (when terrain is enabled) elevation is sampled for the point before
* projecting it. In 2D mode, behaves the same locationPoint.
* @param {LngLat} lnglat location
* @returns {Point} screen point
* @private
*/
locationPoint3D(lnglat: LngLat) {
return this._coordinatePoint(this.locationCoordinate(lnglat), true);
}
/**
* Given a point on screen, return its lnglat
* @param {Point} p screen point
* @returns {LngLat} lnglat location
* @private
*/
pointLocation(p: Point) {
return this.coordinateLocation(this.pointCoordinate(p));
}
/**
* Given a point on screen, return its lnglat
* In 3D mode (map with terrain) returns location of terrain raycast point.
* In 2D mode, behaves the same as {@see pointLocation}.
* @param {Point} p screen point
* @returns {LngLat} lnglat location
* @private
*/
pointLocation3D(p: Point) {
return this.coordinateLocation(this.pointCoordinate3D(p));
}
/**
* Given a geographical lnglat, return an unrounded
* coordinate that represents it at this transform's zoom level.
* @param {LngLat} lnglat
* @returns {Coordinate}
* @private
*/
locationCoordinate(lnglat: LngLat) {
return MercatorCoordinate.fromLngLat(lnglat);
}
/**
* Given a Coordinate, return its geographical position.
* @param {Coordinate} coord
* @returns {LngLat} lnglat
* @private
*/
coordinateLocation(coord: MercatorCoordinate) {
return coord.toLngLat();
}
/**
* Casts a ray from a point on screen and returns the Ray,
* and the extent along it, at which it intersects the map plane.
*
* @param {Point} p viewport pixel co-ordinates
* @param {number} z optional altitude of the map plane
* @returns {{ p0: vec4, p1: vec4, t: number }} p0,p1 are two points on the ray
* t is the fractional extent along the ray at which the ray intersects the map plane
* @private
*/
pointRayIntersection(p: Point, z: ?number): RayIntersectionResult {
const targetZ = (z !== undefined && z !== null) ? z : this._centerAltitude;
// since we don't know the correct projected z value for the point,
// unproject two points to get a line and then find the point on that
// line with z=0
const p0 = [p.x, p.y, 0, 1];
const p1 = [p.x, p.y, 1, 1];
vec4.transformMat4(p0, p0, this.pixelMatrixInverse);
vec4.transformMat4(p1, p1, this.pixelMatrixInverse);
const w0 = p0[3];
const w1 = p1[3];
vec4.scale(p0, p0, 1 / w0);
vec4.scale(p1, p1, 1 / w1);
const z0 = p0[2];
const z1 = p1[2];
const t = z0 === z1 ? 0 : (targetZ - z0) / (z1 - z0);
return {p0, p1, t};
}
screenPointToMercatorRay(p: Point): Ray {
const p0 = [p.x, p.y, 0, 1];
const p1 = [p.x, p.y, 1, 1];
vec4.transformMat4(p0, p0, this.pixelMatrixInverse);
vec4.transformMat4(p1, p1, this.pixelMatrixInverse);
vec4.scale(p0, p0, 1 / p0[3]);
vec4.scale(p1, p1, 1 / p1[3]);
// Convert altitude from meters to pixels
p0[2] = mercatorZfromAltitude(p0[2], this._center.lat) * this.worldSize;
p1[2] = mercatorZfromAltitude(p1[2], this._center.lat) * this.worldSize;
vec4.scale(p0, p0, 1 / this.worldSize);
vec4.scale(p1, p1, 1 / this.worldSize);
return new Ray([p0[0], p0[1], p0[2]], vec3.normalize([], vec3.sub([], p1, p0)));
}
/**
* Helper method to convert the ray intersection with the map plane to MercatorCoordinate
*
* @param {RayIntersectionResult} rayIntersection
* @returns {MercatorCoordinate}
* @private
*/
rayIntersectionCoordinate(rayIntersection: RayIntersectionResult): MercatorCoordinate {
const {p0, p1, t} = rayIntersection;
const z0 = mercatorZfromAltitude(p0[2], this._center.lat);
const z1 = mercatorZfromAltitude(p1[2], this._center.lat);
return new MercatorCoordinate(
interpolate(p0[0], p1[0], t) / this.worldSize,
interpolate(p0[1], p1[1], t) / this.worldSize,
interpolate(z0, z1, t));
}
/**
* Given a point on screen, returns MercatorCoordinate.
* @param {Point} p top left origin screen point, in pixels.
* @private
*/
pointCoordinate(p: Point): MercatorCoordinate {
const horizonOffset = this.horizonLineFromTop(false);
const clamped = new Point(p.x, Math.max(horizonOffset, p.y));
return this.rayIntersectionCoordinate(this.pointRayIntersection(clamped));
}
/**
* Given a point on screen, returns MercatorCoordinate.
* In 3D mode, raycast to terrain. In 2D mode, behaves the same as {@see pointCoordinate}.
* For p above terrain, don't return point behind camera but clamp p.y at the top of terrain.
* @param {Point} p top left origin screen point, in pixels.
* @private
*/
pointCoordinate3D(p: Point): MercatorCoordinate {
if (!this.elevation) return this.pointCoordinate(p);
const elevation = this.elevation;
let raycast = this.elevation.pointCoordinate(p);
if (raycast) return new MercatorCoordinate(raycast[0], raycast[1], raycast[2]);
let start = 0, end = this.horizonLineFromTop();
if (p.y > end) return this.pointCoordinate(p); // holes between tiles below horizon line or below bottom.
const samples = 10;
const threshold = 0.02 * end;
const r = p.clone();
for (let i = 0; i < samples && end - start > threshold; i++) {
r.y = interpolate(start, end, 0.66); // non uniform binary search favoring points closer to horizon.
const rCast = elevation.pointCoordinate(r);
if (rCast) {
end = r.y;
raycast = rCast;
} else {
start = r.y;
}
}
return raycast ? new MercatorCoordinate(raycast[0], raycast[1], raycast[2]) : this.pointCoordinate(p);
}
/**
* Returns true if a screenspace Point p, is above the horizon.
* This approximates the map as an infinite plane and does not account for z0-z3
* wherein the map is small quad with whitespace above the north pole and below the south pole.
*
* @param {Point} p
* @returns {boolean}
* @private
*/
isPointAboveHorizon(p: Point): boolean {
if (!this.elevation) {
const horizon = this.horizonLineFromTop();
return p.y < horizon;
} else {
return !this.elevation.pointCoordinate(p);
}
}
/**
* Given a coordinate, return the screen point that corresponds to it
* @param {Coordinate} coord
* @param {boolean} sampleTerrainIn3D in 3D mode (terrain enabled), sample elevation for the point.
* If false, do the same as in 2D mode, assume flat camera elevation plane for all points.
* @returns {Point} screen point
* @private
*/
_coordinatePoint(coord: MercatorCoordinate, sampleTerrainIn3D: boolean) {
const elevation = sampleTerrainIn3D && this.elevation ? this.elevation.getAtPointOrZero(coord, this._centerAltitude) : this._centerAltitude;
const p = [coord.x * this.worldSize, coord.y * this.worldSize, elevation + coord.toAltitude(), 1];
vec4.transformMat4(p, p, this.pixelMatrix);
return p[3] > 0 ?
new Point(p[0] / p[3], p[1] / p[3]) :
new Point(Number.MAX_VALUE, Number.MAX_VALUE);
}
/**
* Returns the map's geographical bounds. When the bearing or pitch is non-zero, the visible region is not
* an axis-aligned rectangle, and the result is the smallest bounds that encompasses the visible region.
* @returns {LngLatBounds} Returns a {@link LngLatBounds} object describing the map's geographical bounds.
*/
getBounds(): LngLatBounds {
if (this._terrainEnabled()) return this._getBounds3D();
return new LngLatBounds()
.extend(this.pointLocation(new Point(this._edgeInsets.left, this._edgeInsets.top)))
.extend(this.pointLocation(new Point(this.width - this._edgeInsets.right, this._edgeInsets.top)))
.extend(this.pointLocation(new Point(this.width - this._edgeInsets.right, this.height - this._edgeInsets.bottom)))
.extend(this.pointLocation(new Point(this._edgeInsets.left, this.height - this._edgeInsets.bottom)));
}
_getBounds3D(): LngLatBounds {
assert(this.elevation);
const elevation = ((this.elevation: any): Elevation);
const minmax = elevation.visibleDemTiles.reduce((acc, t) => {
if (t.dem) {
const tree = t.dem.tree;
acc.min = Math.min(acc.min, tree.minimums[0]);
acc.max = Math.max(acc.max, tree.maximums[0]);
}
return acc;
}, {min: Number.MAX_VALUE, max: 0});
minmax.min *= elevation.exaggeration();
minmax.max *= elevation.exaggeration();
const top = this.horizonLineFromTop();
return [
new Point(0, top),
new Point(this.width, top),
new Point(this.width, this.height),
new Point(0, this.height)
].reduce((acc, p) => {
return acc
.extend(this.coordinateLocation(this.rayIntersectionCoordinate(this.pointRayIntersection(p, minmax.min))))
.extend(this.coordinateLocation(this.rayIntersectionCoordinate(this.pointRayIntersection(p, minmax.max))));
}, new LngLatBounds());
}
/**
* Returns position of horizon line from the top of the map in pixels. If horizon is not visible, returns 0.
* @private
*/
horizonLineFromTop(clampToTop: boolean = true): number {
// h is height of space above map center to horizon.
const h = this.height / 2 / Math.tan(this._fov / 2) / Math.tan(Math.max(this._pitch, 0.1)) + this.centerOffset.y;
// incorporate 3% of the area above center to account for reduced precision.
const horizonEpsilon = 0.03;
const offset = this.height / 2 - h * (1 - horizonEpsilon);
return clampToTop ? Math.max(0, offset) : offset;
}
/**
* Returns the maximum geographical bounds the map is constrained to, or `null` if none set.
* @returns {LngLatBounds} {@link LngLatBounds}
*/
getMaxBounds(): LngLatBounds | null {
if (!this.latRange || this.latRange.length !== 2 ||
!this.lngRange || this.lngRange.length !== 2) return null;
return new LngLatBounds([this.lngRange[0], this.latRange[0]], [this.lngRange[1], this.latRange[1]]);
}
/**
* Sets or clears the map's geographical constraints.
* @param {LngLatBounds} bounds A {@link LngLatBounds} object describing the new geographic boundaries of the map.
*/
setMaxBounds(bounds?: LngLatBounds) {
if (bounds) {
this.lngRange = [bounds.getWest(), bounds.getEast()];
this.latRange = [bounds.getSouth(), bounds.getNorth()];
this._constrain();
} else {
this.lngRange = null;
this.latRange = [-this.maxValidLatitude, this.maxValidLatitude];
}
}
calculatePosMatrix(unwrappedTileID: UnwrappedTileID, worldSize: number): Float32Array {
const canonical = unwrappedTileID.canonical;
const scale = worldSize / this.zoomScale(canonical.z);
const unwrappedX = canonical.x + Math.pow(2, canonical.z) * unwrappedTileID.wrap;
const posMatrix = mat4.identity(new Float64Array(16));
mat4.translate(posMatrix, posMatrix, [unwrappedX * scale, canonical.y * scale, 0]);
mat4.scale(posMatrix, posMatrix, [scale / EXTENT, scale / EXTENT, 1]);
return posMatrix;
}
/**
* Calculate the fogTileMatrix that, given a tile coordinate, can be used to
* calculate its position relative to the camera in units of pixels divided
* by the map height. Used with fog for consistent computation of distance
* from camera.
*
* @param {UnwrappedTileID} unwrappedTileID;
* @private
*/
calculateFogTileMatrix(unwrappedTileID: UnwrappedTileID): Float32Array {
const fogTileMatrixKey = unwrappedTileID.key;
const cache = this._fogTileMatrixCache;
if (cache[fogTileMatrixKey]) {
return cache[fogTileMatrixKey];
}
const posMatrix = this.calculatePosMatrix(unwrappedTileID, this.cameraWorldSize);
mat4.multiply(posMatrix, this.worldToFogMatrix, posMatrix);
cache[fogTileMatrixKey] = new Float32Array(posMatrix);
return cache[fogTileMatrixKey];
}
/**
* Calculate the projMatrix that, given a tile coordinate, would be used to display the tile on the screen.
* @param {UnwrappedTileID} unwrappedTileID;
* @private
*/
calculateProjMatrix(unwrappedTileID: UnwrappedTileID, aligned: boolean = false): Float32Array {
const projMatrixKey = unwrappedTileID.key;
const cache = aligned ? this._alignedProjMatrixCache : this._projMatrixCache;
if (cache[projMatrixKey]) {
return cache[projMatrixKey];
}
const posMatrix = this.calculatePosMatrix(unwrappedTileID, this.worldSize);
mat4.multiply(posMatrix, aligned ? this.alignedProjMatrix : this.projMatrix, posMatrix);
cache[projMatrixKey] = new Float32Array(posMatrix);
return cache[projMatrixKey];
}
customLayerMatrix(): Array<number> {
return this.mercatorMatrix.slice();
}
recenterOnTerrain() {
if (!this._elevation)
return;
con