mapbox-gl
Version:
A WebGL interactive maps library
1,183 lines (1,019 loc) • 111 kB
JavaScript
// @flow
import LngLat from './lng_lat.js';
import LngLatBounds from './lng_lat_bounds.js';
import MercatorCoordinate, {mercatorXfromLng, mercatorYfromLat, mercatorZfromAltitude, latFromMercatorY, MAX_MERCATOR_LATITUDE, circumferenceAtLatitude} from './mercator_coordinate.js';
import {getProjection} from './projection/index.js';
import {tileAABB} from '../geo/projection/tile_transform.js';
import Point from '@mapbox/point-geometry';
import {wrap, clamp, pick, radToDeg, degToRad, getAABBPointSquareDist, furthestTileCorner, warnOnce, deepEqual} from '../util/util.js';
import {number as interpolate} from '../style-spec/util/interpolate.js';
import EXTENT from '../style-spec/data/extent.js';
import {vec4, mat4, mat2, vec3, quat} from 'gl-matrix';
import {Frustum, FrustumCorners, 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 getProjectionAdjustments, {getProjectionAdjustmentInverted, getScaleAdjustment, getProjectionInterpolationT} from './projection/adjustments.js';
import {getPixelsToTileUnitsMatrix} from '../source/pixels_to_tile_units.js';
import {UnwrappedTileID, OverscaledTileID, CanonicalTileID} from '../source/tile_id.js';
import {
calculateGlobeMatrix,
polesInViewport,
aabbForTileOnGlobe,
GLOBE_ZOOM_THRESHOLD_MIN,
GLOBE_ZOOM_THRESHOLD_MAX,
GLOBE_SCALE_MATCH_LATITUDE
} from '../geo/projection/globe_util.js';
import {projectClamped} from '../symbol/projection.js';
import type Projection from '../geo/projection/projection.js';
import type {Elevation} from '../terrain/elevation.js';
import type {PaddingOptions} from './edge_insets.js';
import type Tile from '../source/tile.js';
import type {ProjectionSpecification} from '../style-spec/types.js';
import type {FeatureDistanceData} from '../style-spec/feature_filter/index.js';
import type {Mat4, Vec3, Vec4, Quat} from 'gl-matrix';
import type {Aabb} from '../util/primitives';
const NUM_WORLD_COPIES = 3;
export const DEFAULT_MIN_ZOOM = 0;
export const DEFAULT_MAX_ZOOM = 25.5;
export const MIN_LOD_PITCH = 60.0;
type RayIntersectionResult = { p0: Vec4, p1: Vec4, t: number};
type ElevationReference = "sea" | "ground";
type RootTile = {
aabb: Aabb,
fullyVisible: boolean,
maxZ: number,
minZ: number,
shouldSplit?: boolean,
tileID?: OverscaledTileID,
wrap: number,
x: number,
y: number,
zoom: number,
};
const OrthographicPitchTranstionValue = 15;
const lerp = (x: number, y: number, t: number) => { return (1 - t) * x + t * y; };
const easeIn = (x: number) => {
return x * x * x * x * x;
};
const lerpMatrix = (out: Float64Array, a: Float64Array, b: Float64Array, value: number) => {
for (let i = 0; i < 16; i++) {
out[i] = lerp(a[i], b[i], value);
}
return out;
};
/**
* A single transform, generally used for a single tile to be
* scaled, rotated, and zoomed.
* @private
*/
class Transform {
tileSize: number;
tileZoom: number;
maxBounds: ?LngLatBounds;
// 2^zoom (worldSize = tileSize * scale)
scale: number;
// Map viewport size (not including the pixel ratio)
width: number;
height: number;
// Bearing, radians, in [-pi, pi]
angle: number;
// 2D rotation matrix in the horizontal plane, as a function of bearing
rotationMatrix: Float32Array;
// Zoom, modulo 1
zoomFraction: number;
// The scale factor component of the conversion from pixels ([0, w] x [h, 0]) to GL
// NDC ([1, -1] x [1, -1]) (note flipped y)
pixelsToGLUnits: [number, number];
// Distance from camera to the center, in screen pixel units, independent of zoom
cameraToCenterDistance: number;
// Projection from mercator coordinates ([0, 0] nw, [1, 1] se) to GL clip coordinates
mercatorMatrix: Array<number>;
// Translate points in mercator coordinates to be centered about the camera, with units chosen
// for screen-height-independent scaling of fog. Not affected by orientation of camera.
mercatorFogMatrix: Float32Array;
// Projection from world coordinates (mercator scaled by worldSize) to clip coordinates
projMatrix: Array<number> | Float32Array | Float64Array;
invProjMatrix: Float64Array;
// Projection matrix with expanded farZ on globe projection
expandedFarZProjMatrix: Array<number> | Float32Array | Float64Array;
// Same as projMatrix, pixel-aligned to avoid fractional pixels for raster tiles
alignedProjMatrix: Float64Array;
// From world coordinates to screen pixel coordinates (projMatrix premultiplied by labelPlaneMatrix)
pixelMatrix: Float64Array;
pixelMatrixInverse: Float64Array;
worldToFogMatrix: Float64Array;
skyboxMatrix: Float32Array;
starsProjMatrix: Float32Array;
// Transform from screen coordinates to GL NDC, [0, w] x [h, 0] --> [-1, 1] x [-1, 1]
// Roughly speaking, applies pixelsToGLUnits scaling with a translation
glCoordMatrix: Float32Array;
// Inverse of glCoordMatrix, from NDC to screen coordinates, [-1, 1] x [-1, 1] --> [0, w] x [h, 0]
labelPlaneMatrix: Float32Array;
// globe coordinate transformation matrix
globeMatrix: Float64Array;
globeCenterInViewSpace: [number, number, number];
globeRadius: number;
inverseAdjustmentMatrix: Array<number>;
mercatorFromTransition: boolean;
minLng: number;
maxLng: number;
minLat: number;
maxLat: number;
worldMinX: number;
worldMaxX: number;
worldMinY: number;
worldMaxY: number;
cameraFrustum: Frustum;
frustumCorners: FrustumCorners;
freezeTileCoverage: boolean;
cameraElevationReference: ElevationReference;
fogCullDistSq: ?number;
_averageElevation: number;
projectionOptions: ProjectionSpecification;
projection: Projection;
_elevation: ?Elevation;
_fov: number;
_pitch: number;
_zoom: number;
_seaLevelZoom: ?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};
_pixelsToTileUnitsCache: {[_: number]: Float32Array};
_expandedProjMatrixCache: {[_: number]: Float32Array};
_fogTileMatrixCache: {[_: number]: Float32Array};
_distanceTileDataCache: {[_: number]: FeatureDistanceData};
_camera: FreeCamera;
_centerAltitude: number;
_centerAltitudeValidForExaggeration: ?number;
_horizonShift: number;
_pixelsPerMercatorPixel: number;
_nearZ: number;
_farZ: number;
_mercatorScaleRatio: number;
_isCameraConstrained: boolean;
_orthographicProjectionAtLowPitch: boolean;
constructor(minZoom: ?number, maxZoom: ?number, minPitch: ?number, maxPitch: ?number, renderWorldCopies: boolean | void, projection?: ?ProjectionSpecification, bounds: ?LngLatBounds) {
this.tileSize = 512; // 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.setProjection(projection);
this.setMaxBounds(bounds);
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._nearZ = 0;
this._farZ = 0;
this._unmodified = true;
this._edgeInsets = new EdgeInsets();
this._projMatrixCache = {};
this._alignedProjMatrixCache = {};
this._fogTileMatrixCache = {};
this._expandedProjMatrixCache = {};
this._distanceTileDataCache = {};
this._camera = new FreeCamera();
this._centerAltitude = 0;
this._averageElevation = 0;
this.cameraElevationReference = "ground";
this._pixelsPerMercatorPixel = 1.0;
this.globeRadius = 0;
this.globeCenterInViewSpace = [0, 0, 0];
// 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;
this._orthographicProjectionAtLowPitch = false;
}
clone(): Transform {
const clone = new Transform(this._minZoom, this._maxZoom, this._minPitch, this.maxPitch, this._renderWorldCopies, this.getProjection());
clone._elevation = this._elevation;
clone._centerAltitude = this._centerAltitude;
clone._centerAltitudeValidForExaggeration = this._centerAltitudeValidForExaggeration;
clone.tileSize = this.tileSize;
clone.mercatorFromTransition = this.mercatorFromTransition;
clone.width = this.width;
clone.height = this.height;
clone.cameraElevationReference = this.cameraElevationReference;
clone._center = this._center;
clone._setZoom(this.zoom);
clone._seaLevelZoom = this._seaLevelZoom;
clone.angle = this.angle;
clone._fov = this._fov;
clone._pitch = this._pitch;
clone._nearZ = this._nearZ;
clone._farZ = this._farZ;
clone._averageElevation = this._averageElevation;
clone._orthographicProjectionAtLowPitch = this._orthographicProjectionAtLowPitch;
clone._unmodified = this._unmodified;
clone._edgeInsets = this._edgeInsets.clone();
clone._camera = this._camera.clone();
clone._calcMatrices();
clone.freezeTileCoverage = this.freezeTileCoverage;
clone.frustumCorners = this.frustumCorners;
return clone;
}
get isOrthographic(): boolean {
return this.projection.name !== 'globe' && this._orthographicProjectionAtLowPitch && this.pitch < OrthographicPitchTranstionValue;
}
get elevation(): ?Elevation { return this._elevation; }
set elevation(elevation: ?Elevation) {
if (this._elevation === elevation) return;
this._elevation = elevation;
this._updateCameraOnTerrain();
this._calcMatrices();
}
get depthOcclusionForSymbolsAndCircles(): boolean {
return this.projection.name !== 'globe' && !this.isOrthographic;
}
updateElevation(constrainCameraOverTerrain: boolean, adaptCameraAltitude: boolean = false) {
const centerAltitudeChanged = this._elevation && this._elevation.exaggeration() !== this._centerAltitudeValidForExaggeration;
if (this._seaLevelZoom == null || centerAltitudeChanged) {
this._updateCameraOnTerrain();
}
if (constrainCameraOverTerrain || centerAltitudeChanged) {
this._constrainCamera(adaptCameraAltitude);
}
this._calcMatrices();
}
getProjection(): ProjectionSpecification {
return (pick(this.projection, ['name', 'center', 'parallels']): ProjectionSpecification);
}
// Returns whether the projection changes
setProjection(projection?: ?ProjectionSpecification): boolean {
this.projectionOptions = projection || {name: 'mercator'};
const oldProjection = this.projection ? this.getProjection() : undefined;
this.projection = getProjection(this.projectionOptions);
const newProjection = this.getProjection();
const projectionHasChanged = !deepEqual(oldProjection, newProjection);
if (projectionHasChanged) {
this._calcMatrices();
}
this.mercatorFromTransition = false;
return projectionHasChanged;
}
// Returns whether the projection need to be reevaluated
setOrthographicProjectionAtLowPitch(enabled: boolean): boolean {
if (this._orthographicProjectionAtLowPitch === enabled) {
return false;
}
this._orthographicProjectionAtLowPitch = enabled;
this._calcMatrices();
return true;
}
setMercatorFromTransition(): boolean {
const oldProjection = this.projection.name;
this.mercatorFromTransition = true;
this.projectionOptions = {name: 'mercator'};
this.projection = getProjection({name: 'mercator'});
const projectionHasChanged = oldProjection !== this.projection.name;
if (projectionHasChanged) {
this._calcMatrices();
}
return projectionHasChanged;
}
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 && this.projection.supportsWorldCopies === true;
}
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;
}
// This getter returns an incorrect value.
// It should eventually be removed and cameraWorldSize be used instead.
// See free_camera.getDistanceToElevation for the rationale.
get cameraWorldSizeForFog(): number {
const distance = Math.max(this._camera.getDistanceToElevation(this._averageElevation), Number.EPSILON);
return this._worldSizeFromZoom(this._zoomFromMercatorZ(distance));
}
get cameraWorldSize(): number {
const distance = Math.max(this._camera.getDistanceToElevation(this._averageElevation, true), Number.EPSILON);
return this._worldSizeFromZoom(this._zoomFromMercatorZ(distance));
}
// `pixelsPerMeter` is used to describe relation between real world and pixel distances.
// In mercator projection it is dependant on latitude value meaning that one meter covers
// less pixels at the equator than near polar regions. Globe projection in other hand uses
// fixed ratio everywhere.
get pixelsPerMeter(): number {
return this.projection.pixelsPerMeter(this.center.lat, this.worldSize);
}
get cameraPixelsPerMeter(): number {
return mercatorZfromAltitude(1, this.center.lat) * this.cameraWorldSizeForFog;
}
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 wrap(this.rotation, -180, 180);
}
set bearing(bearing: number) {
this.rotation = bearing;
}
get rotation(): number {
return -this.angle / Math.PI * 180;
}
set rotation(rotation: number) {
const b = -rotation * 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 aspect(): number {
return this.width / this.height;
}
get fov(): number {
return this._fov / Math.PI * 180;
}
get fovX(): number {
return this._fov;
}
get fovY(): number {
const focalLength = 1.0 / Math.tan(this.fovX * 0.5);
return 2 * Math.atan((1.0 / this.aspect) / focalLength);
}
set fov(fov: number) {
fov = Math.max(0.01, Math.min(60, fov));
if (this._fov === fov) return;
this._unmodified = false;
this._fov = degToRad(fov);
this._calcMatrices();
}
get averageElevation(): number {
return this._averageElevation;
}
set averageElevation(averageElevation: number) {
this._averageElevation = averageElevation;
this._calcFogMatrices();
this._distanceTileDataCache = {};
}
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);
this._updateSeaLevelZoom();
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;
}
_updateCameraOnTerrain() {
const elevationAtCenter = this.elevation ? this.elevation.getAtPoint(this.locationCoordinate(this.center), Number.NEGATIVE_INFINITY) : Number.NEGATIVE_INFINITY;
const usePreviousCenter = this.elevation && elevationAtCenter === Number.NEGATIVE_INFINITY && this.elevation.visibleDemTiles.length > 0 && this.elevation.exaggeration() > 0 &&
this._centerAltitudeValidForExaggeration;
if (!this._elevation || (elevationAtCenter === Number.NEGATIVE_INFINITY && !(usePreviousCenter && this._centerAltitude))) {
// Elevation data not loaded yet, reset
this._centerAltitude = 0;
this._seaLevelZoom = null;
this._centerAltitudeValidForExaggeration = undefined;
return;
}
const elevation: Elevation = this._elevation;
if (usePreviousCenter || (this._centerAltitude && this._centerAltitudeValidForExaggeration &&
elevation.exaggeration() && this._centerAltitudeValidForExaggeration !== elevation.exaggeration())) {
assert(this._centerAltitudeValidForExaggeration);
const previousExaggeration = (this._centerAltitudeValidForExaggeration: any);
// scale down the centerAltitude
this._centerAltitude = this._centerAltitude / previousExaggeration * elevation.exaggeration();
this._centerAltitudeValidForExaggeration = elevation.exaggeration();
} else {
this._centerAltitude = elevationAtCenter || 0;
this._centerAltitudeValidForExaggeration = elevation.exaggeration();
}
this._updateSeaLevelZoom();
}
_updateSeaLevelZoom() {
if (this._centerAltitudeValidForExaggeration === undefined) {
return;
}
const height = this.cameraToCenterDistance;
const terrainElevation = this.pixelsPerMeter * this._centerAltitude;
const mercatorZ = (terrainElevation + height) / this.worldSize;
// MSL (Mean Sea Level) 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.
this._seaLevelZoom = this._zoomFromMercatorZ(mercatorZ);
}
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") {
this._updateCameraOnTerrain();
} else {
this._updateZoomFromElevation();
}
}
this._constrain();
this._calcMatrices();
}
_updateZoomFromElevation() {
if (this._seaLevelZoom == null || !this._elevation)
return;
// Compute zoom level from the height of the camera relative to the terrain
const seaLevelZoom: number = this._seaLevelZoom;
const elevationAtCenter = this._elevation.getAtPointOrZero(this.locationCoordinate(this.center));
const mercatorElevation = this.pixelsPerMeter / this.worldSize * elevationAtCenter;
const altitude = this._mercatorZfromZoom(seaLevelZoom);
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)) {
// $FlowFixMe[incompatible-call] - Flow can't infer that orientation is not null
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 the highest zoom level that fully includes all tiles within the transform's boundaries.
* @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} An integer zoom level at which all tiles will be visible.
*/
coveringZoomLevel(options: {roundZoom?: boolean, tileSize: number}): 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): Array<UnwrappedTileID> {
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;
}
isLODDisabled(checkPitch: boolean): boolean {
// 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
return (!checkPitch || this.pitch <= MIN_LOD_PITCH) && this._edgeInsets.top <= this._edgeInsets.bottom && !this._elevation && !this.projection.isReprojectedInTileSpace;
}
/**
* Extends tile coverage to include potential shadow caster tiles.
* @param {Array<OverscaledTileID>} coveringTiles tiles that are potential shadow receivers
* @param {Vec3} lightDir direction of the light (unit vector)
* @param {number} maxZoom maximum zoom level of shadow caster tiles
* @returns {Array<OverscaledTileID>} a set of potential shadow casters
*/
extendTileCoverForShadows(coveringTiles: Array<OverscaledTileID>, lightDir: Vec3, maxZoom: number): Array<OverscaledTileID> {
let out = [];
if (lightDir[0] === 0.0 && lightDir[1] === 0.0) {
return out;
}
// Extra tile selection based on the direction of the light:
// For each tile we add neighbourgs that might cast shadows over the current tile
for (const id of coveringTiles) {
const tileId = id.canonical;
const overscaledZ = id.overscaledZ;
const tileWrap = id.wrap;
const tiles = 1 << tileId.z;
const xMaxInsideRange = tileId.x + 1 < tiles;
const xMinInsideRange = tileId.x > 0;
const yMaxInsideRange = tileId.y + 1 < tiles;
const yMinInsideRange = tileId.y > 0;
const leftWrap = id.wrap - (xMinInsideRange ? 0 : 1);
const rightWrap = id.wrap + (xMaxInsideRange ? 0 : 1);
const leftTileX = xMinInsideRange ? tileId.x - 1 : tiles - 1;
const rightTileX = xMaxInsideRange ? tileId.x + 1 : 0;
if (lightDir[0] < 0.0) {
out.push(new OverscaledTileID(overscaledZ, rightWrap, tileId.z, rightTileX, tileId.y));
if (lightDir[1] < 0.0 && yMaxInsideRange) {
out.push(new OverscaledTileID(overscaledZ, tileWrap, tileId.z, tileId.x, tileId.y + 1));
out.push(new OverscaledTileID(overscaledZ, rightWrap, tileId.z, rightTileX, tileId.y + 1));
}
if (lightDir[1] > 0.0 && yMinInsideRange) {
out.push(new OverscaledTileID(overscaledZ, tileWrap, tileId.z, tileId.x, tileId.y - 1));
out.push(new OverscaledTileID(overscaledZ, rightWrap, tileId.z, rightTileX, tileId.y - 1));
}
} else if (lightDir[0] > 0.0) {
out.push(new OverscaledTileID(overscaledZ, leftWrap, tileId.z, leftTileX, tileId.y));
if (lightDir[1] < 0.0 && yMaxInsideRange) {
out.push(new OverscaledTileID(overscaledZ, tileWrap, tileId.z, tileId.x, tileId.y + 1));
out.push(new OverscaledTileID(overscaledZ, leftWrap, tileId.z, leftTileX, tileId.y + 1));
}
if (lightDir[1] > 0.0 && yMinInsideRange) {
out.push(new OverscaledTileID(overscaledZ, tileWrap, tileId.z, tileId.x, tileId.y - 1));
out.push(new OverscaledTileID(overscaledZ, leftWrap, tileId.z, leftTileX, tileId.y - 1));
}
} else {
if (lightDir[1] < 0.0 && yMaxInsideRange) {
out.push(new OverscaledTileID(overscaledZ, tileWrap, tileId.z, tileId.x, tileId.y + 1));
} else if (yMinInsideRange) {
out.push(new OverscaledTileID(overscaledZ, tileWrap, tileId.z, tileId.x, tileId.y - 1));
}
}
}
// Remove duplicates from new ids
if (out.length > 1) {
out.sort((a, b) => {
return a.overscaledZ - b.overscaledZ ||
a.wrap - b.wrap ||
a.canonical.z - b.canonical.z ||
a.canonical.x - b.canonical.x ||
a.canonical.y - b.canonical.y;
});
let i = 0;
let j = 0;
while (j < out.length) {
if (!out[j].equals(out[i])) {
out[++i] = out[j++];
} else {
++j;
}
}
out.length = i + 1;
}
// Remove higher zoom new IDs that overlap with other new IDs
const nonOverlappingIds = [];
for (const id of out) {
if (!out.some(ancestorCandidate => id.isChildOf(ancestorCandidate))) {
nonOverlappingIds.push(id);
}
}
// Remove new IDs that overlap with old IDs
out = nonOverlappingIds.filter(newId => !coveringTiles.some(oldId => {
if (newId.overscaledZ < maxZoom && oldId.isChildOf(newId)) {
return true;
}
// Remove identical IDs or children of existing IDs
return newId.equals(oldId) || newId.isChildOf(oldId);
}));
return out;
}
/**
* 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 hasExaggeration = this.elevation && this.elevation.exaggeration();
const useElevationData = hasExaggeration && !options.isTerrainDEM;
const isMercator = this.projection.name === 'mercator';
if (options.minzoom !== undefined && z < options.minzoom) return [];
if (options.maxzoom !== undefined && z > options.maxzoom) z = options.maxzoom;
const centerCoord = this.locationCoordinate(this.center);
const centerLatitude = this.center.lat;
const numTiles = 1 << z;
const centerPoint = [numTiles * centerCoord.x, numTiles * centerCoord.y, 0];
const isGlobe = this.projection.name === 'globe';
const zInMeters = !isGlobe;
const cameraFrustum = Frustum.fromInvProjectionMatrix(this.invProjMatrix, this.worldSize, z, zInMeters);
const cameraCoord = isGlobe ? this._camera.mercatorPosition : 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 * (zInMeters ? 1 : meterToTile)];
const verticalFrustumIntersect = isGlobe || hasExaggeration;
// 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);
const minZoom = this.isLODDisabled(true) ? 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°).
let maxRange;
if (this._elevation && options.isTerrainDEM) {
maxRange = this._elevation.exaggeration() * 10000;
} else if (this._elevation) {
const minMaxOpt = this._elevation.getMinMaxForVisibleTiles();
maxRange = minMaxOpt ? minMaxOpt.max : this._centerAltitude;
} else {
maxRange = this._centerAltitude;
}
const minRange = options.isTerrainDEM ? -maxRange : this._elevation ? this._elevation.getMinElevationBelowMSL() : 0;
const scaleAdjustment = this.projection.isReprojectedInTileSpace ? getScaleAdjustment(this) : 1.0;
const relativeScaleAtMercatorCoord = (mc: MercatorCoordinate) => {
// Calculate how scale compares between projected coordinates and mercator coordinates.
// Returns a length. The units don't matter since the result is only
// used in a ratio with other values returned by this function.
// Construct a small square in Mercator coordinates.
const offset = 1 / 40000;
const mcEast = new MercatorCoordinate(mc.x + offset, mc.y, mc.z);
const mcSouth = new MercatorCoordinate(mc.x, mc.y + offset, mc.z);
// Convert the square to projected coordinates.
const ll = mc.toLngLat();
const llEast = mcEast.toLngLat();
const llSouth = mcSouth.toLngLat();
const p = this.locationCoordinate(ll);
const pEast = this.locationCoordinate(llEast);
const pSouth = this.locationCoordinate(llSouth);
// Calculate the size of each edge of the reprojected square
const dx = Math.hypot(pEast.x - p.x, pEast.y - p.y);
const dy = Math.hypot(pSouth.x - p.x, pSouth.y - p.y);
// Calculate the size of a projected square that would have the
// same area as the reprojected square.
return Math.sqrt(dx * dy) * scaleAdjustment / offset;
};
const newRootTile = (wrap: number): RootTile => {
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: tileAABB(this, numTiles, 0, 0, 0, wrap, min, max, this.projection),
zoom: 0,
x: 0,
y: 0,
minZ: min,
maxZ: max,
wrap,
fullyVisible: false
};
};
// Do a depth-first traversal to find visible tiles and proper levels of detail
const stack = [];
let result = [];
const maxZoom = z;
const overscaledZ = options.reparseOverscaled ? actualZ : z;
const square = (a: number) => a * a;
const cameraHeightSqr = square((cameraAltitude - this._centerAltitude) * meterToTile); // in tile coordinates.
const getAABBFromElevation = (it: RootTile) => {
assert(this._elevation);
if (!this._elevation || !it.tileID || !isMercator) 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;
}
}
};
// 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: number, dSqr: number) => {
// 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: RootTile) => {
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;
let tileScaleAdjustment = 1;
if (isGlobe) {
dzSqr = square(it.aabb.distanceZ(cameraPoint));
// Compensate physical sizes of the tiles when determining which zoom level to use.
// In practice tiles closer to poles should use more aggressive LOD as their
// physical size is already smaller than size of tiles near the equator.
const tilesAtZoom = Math.pow(2, it.zoom);
const minLat = latFromMercatorY((it.y + 1) / tilesAtZoom);
const maxLat = latFromMercatorY((it.y) / tilesAtZoom);
const closestLat = Math.min(Math.max(centerLatitude, minLat), maxLat);
const relativeTileScale = circumferenceAtLatitude(closestLat) / circumferenceAtLatitude(centerLatitude);
// With globe, the rendered scale does not exactly match the mercator scale at low zoom levels.
// Account for this difference during LOD of loading so that you load the correct size tiles.
// We try to compromise between two conflicting requirements:
// - loading tiles at the camera's zoom level (for visual and styling consistency)
// - loading correct size tiles (to reduce the number of tiles loaded)
// These are arbitrarily balanced:
if (closestLat === centerLatitude) {
// For tiles that are in the middle of the viewport, prioritize matching the camera
// zoom and allow divergence from the true scale.
const maxDivergence = 0.3;
tileScaleAdjustment = 1 / Math.max(1, this._mercatorScaleRatio - maxDivergence);
} else {
// For other tiles, use the real scale to reduce tile counts near poles.
tileScaleAdjustment = Math.min(1, relativeTileScale / this._mercatorScaleRatio);
}
// Ensure that all tiles near the center have the same zoom level.
// With LOD tile loading, tile zoom levels can change when scale slightly changes.
// These differences can be pretty different in globe view. Work around this by
// making more tiles match the center tile's zoom level. If the tiles are nearly big enough,
// round up. Only apply this adjustment before the transition to mercator rendering has started.
if (this.zoom <= GLOBE_ZOOM_THRESHOLD_MIN && it.zoom === maxZoom - 1 && relativeTileScale >= 0.9) {
return true;
}
} else {
assert(zInMeters);
if (useElevationData) {
dzSqr = square(it.aabb.distanceZ(cameraPoint) * meterToTile);
}
if (this.projection.isReprojectedInTileSpace && actualZ <= 5) {
// In other projections, not all tiles are the same size.
// Account for the tile size difference by adjusting the distToSplit.
// Adjust by the ratio of the area at the tile center to the area at the map center.
// Adjustments are only needed at lower zooms where tiles are not similarly sized.
const numTiles = Math.pow(2, it.zoom);
const relativeScale = relativeScaleAtMercatorCoord(new MercatorCoordinate((it.x + 0.5) / numTiles, (it.y + 0.5) / numTiles));
// Fudge the ratio slightly so that all tiles near the center have the same zoom level.
tileScaleAdjustment = relativeScale > 0.85 ? 1 : relativeScale;
}
}
const distanceSqr = dx * dx + dy * dy + dzSqr;
const distToSplit = (1 << maxZoom - it.zoom) * zoomSplitDistance * tileScaleAdjustment;
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;
const isPoleNeighbourAndGlobeProjection = () => {
return this.projection.name === 'globe' && (it.y === 0 || it.y === (1 << it.zoom) - 1);
};
// Visibility of a tile is not required if any of its ancestor is fully inside the frustum
if (!fullyVisible) {