mapbox-gl
Version:
A WebGL interactive maps library
768 lines (672 loc) • 26.1 kB
JavaScript
'use strict';
var util = require('../util/util');
var interpolate = require('../util/interpolate');
var browser = require('../util/browser');
var LngLat = require('../geo/lng_lat');
var LngLatBounds = require('../geo/lng_lat_bounds');
var Point = require('point-geometry');
/**
* Options common to Map#jumpTo, Map#easeTo, and Map#flyTo, controlling the destination
* location, zoom level, bearing and pitch. All properties are options; unspecified
* options will default to the current value for that property.
*
* @typedef {Object} CameraOptions
* @property {LngLat} center Map center
* @property {number} zoom Map zoom level
* @property {number} bearing Map rotation bearing in degrees counter-clockwise from north
* @property {number} pitch Map angle in degrees at which the camera is looking at the ground
* @property {LngLat} around If zooming, the zoom center (defaults to map center)
*/
/**
* Options common to map movement methods that involve animation, such as Map#panBy and
* Map#easeTo, controlling the duration of the animation and easing function. All properties
* are optional.
*
* @typedef {Object} AnimationOptions
* @property {number} duration Number in milliseconds
* @property {Function} easing
* @property {Array} offset point, origin of movement relative to map center
* @property {boolean} animate When set to false, no animation happens
*/
var Camera = module.exports = function() {};
util.extend(Camera.prototype, /** @lends Map.prototype */{
/**
* Get the current view geographical point.
* @returns {LngLat}
*/
getCenter: function() { return this.transform.center; },
/**
* Sets a map location. Equivalent to `jumpTo({center: center})`.
*
* @param {LngLat} center Map center to jump to
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
* @example
* map.setCenter([-74, 38]);
*/
setCenter: function(center, eventData) {
this.jumpTo({center: center}, eventData);
return this;
},
/**
* Pan by a certain number of pixels
*
* @param {Array<number>} offset [x, y]
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
*/
panBy: function(offset, options, eventData) {
this.panTo(this.transform.center,
util.extend({offset: Point.convert(offset).mult(-1)}, options), eventData);
return this;
},
/**
* Pan to a certain location with easing
*
* @param {LngLat} lnglat Location to pan to
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
*/
panTo: function(lnglat, options, eventData) {
return this.easeTo(util.extend({
center: lnglat
}, options), eventData);
},
/**
* Get the current zoom
* @returns {number}
*/
getZoom: function() { return this.transform.zoom; },
/**
* Sets a map zoom. Equivalent to `jumpTo({zoom: zoom})`.
*
* @param {number} zoom Map zoom level
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires zoomstart
* @fires move
* @fires zoom
* @fires moveend
* @fires zoomend
* @returns {Map} `this`
* @example
* // zoom the map to 5
* map.setZoom(5);
*/
setZoom: function(zoom, eventData) {
this.jumpTo({zoom: zoom}, eventData);
return this;
},
/**
* Zooms to a certain zoom level with easing.
*
* @param {number} zoom
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires zoomstart
* @fires move
* @fires zoom
* @fires moveend
* @fires zoomend
* @returns {Map} `this`
*/
zoomTo: function(zoom, options, eventData) {
return this.easeTo(util.extend({
zoom: zoom
}, options), eventData);
},
/**
* Zoom in by 1 level
*
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires zoomstart
* @fires move
* @fires zoom
* @fires moveend
* @fires zoomend
* @returns {Map} `this`
*/
zoomIn: function(options, eventData) {
this.zoomTo(this.getZoom() + 1, options, eventData);
return this;
},
/**
* Zoom out by 1 level
*
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires zoomstart
* @fires move
* @fires zoom
* @fires moveend
* @fires zoomend
* @returns {Map} `this`
*/
zoomOut: function(options, eventData) {
this.zoomTo(this.getZoom() - 1, options, eventData);
return this;
},
/**
* Get the current bearing in degrees
* @returns {number}
*/
getBearing: function() { return this.transform.bearing; },
/**
* Sets a map rotation. Equivalent to `jumpTo({bearing: bearing})`.
*
* @param {number} bearing Map rotation bearing in degrees counter-clockwise from north
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
* @example
* // rotate the map to 90 degrees
* map.setBearing(90);
*/
setBearing: function(bearing, eventData) {
this.jumpTo({bearing: bearing}, eventData);
return this;
},
/**
* Rotate bearing by a certain number of degrees with easing
*
* @param {number} bearing
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
*/
rotateTo: function(bearing, options, eventData) {
return this.easeTo(util.extend({
bearing: bearing
}, options), eventData);
},
/**
* Sets map bearing to 0 (north) with easing
*
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
*/
resetNorth: function(options, eventData) {
this.rotateTo(0, util.extend({duration: 1000}, options), eventData);
return this;
},
/**
* Animates map bearing to 0 (north) if it's already close to it.
*
* @param {AnimationOptions} [options]
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
*/
snapToNorth: function(options, eventData) {
if (Math.abs(this.getBearing()) < this.options.bearingSnap) {
return this.resetNorth(options, eventData);
}
return this;
},
/**
* Get the current angle in degrees
* @returns {number}
*/
getPitch: function() { return this.transform.pitch; },
/**
* Sets a map angle. Equivalent to `jumpTo({pitch: pitch})`.
*
* @param {number} pitch The angle at which the camera is looking at the ground
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
*/
setPitch: function(pitch, eventData) {
this.jumpTo({pitch: pitch}, eventData);
return this;
},
/**
* Zoom to contain certain geographical bounds
*
* @param {LngLatBounds|Array<Array<number>>} bounds [[minLng, minLat], [maxLng, maxLat]]
* @param {Object} options
* @param {boolean} [options.linear] When true, the map transitions to the new camera using
* {@link #Map.easeTo}. When false, the map transitions using {@link #Map.flyTo}. See
* {@link #Map.flyTo} for information on options specific to that animation transition.
* @param {Function} options.easing
* @param {number} options.padding how much padding there is around the given bounds on each side in pixels
* @param {number} options.maxZoom The resulting zoom level will be at most
* this value.
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires moveend
* @returns {Map} `this`
*/
fitBounds: function(bounds, options, eventData) {
options = util.extend({
padding: 0,
offset: [0, 0],
maxZoom: Infinity
}, options);
bounds = LngLatBounds.convert(bounds);
var offset = Point.convert(options.offset),
tr = this.transform,
nw = tr.project(bounds.getNorthWest()),
se = tr.project(bounds.getSouthEast()),
size = se.sub(nw),
scaleX = (tr.width - options.padding * 2 - Math.abs(offset.x) * 2) / size.x,
scaleY = (tr.height - options.padding * 2 - Math.abs(offset.y) * 2) / size.y;
options.center = tr.unproject(nw.add(se).div(2));
options.zoom = Math.min(tr.scaleZoom(tr.scale * Math.min(scaleX, scaleY)), options.maxZoom);
options.bearing = 0;
return options.linear ?
this.easeTo(options, eventData) :
this.flyTo(options, eventData);
},
/**
* Change any combination of center, zoom, bearing, and pitch, without
* a transition. The map will retain the current values for any options
* not included in `options`.
*
* @param {CameraOptions} options map view options
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires zoomstart
* @fires move
* @fires zoom
* @fires rotate
* @fires pitch
* @fires zoomend
* @fires moveend
* @returns {Map} `this`
*/
jumpTo: function(options, eventData) {
this.stop();
var tr = this.transform,
zoomChanged = false,
bearingChanged = false,
pitchChanged = false;
if ('zoom' in options && tr.zoom !== +options.zoom) {
zoomChanged = true;
tr.zoom = +options.zoom;
}
if ('center' in options) {
tr.center = LngLat.convert(options.center);
}
if ('bearing' in options && tr.bearing !== +options.bearing) {
bearingChanged = true;
tr.bearing = +options.bearing;
}
if ('pitch' in options && tr.pitch !== +options.pitch) {
pitchChanged = true;
tr.pitch = +options.pitch;
}
this.fire('movestart', eventData)
.fire('move', eventData);
if (zoomChanged) {
this.fire('zoomstart', eventData)
.fire('zoom', eventData)
.fire('zoomend', eventData);
}
if (bearingChanged) {
this.fire('rotate', eventData);
}
if (pitchChanged) {
this.fire('pitch', eventData);
}
return this.fire('moveend', eventData);
},
/**
* Change any combination of center, zoom, bearing, and pitch, with a smooth animation
* between old and new values. The map will retain the current values for any options
* not included in `options`.
*
* @param {CameraOptions|AnimationOptions} options map view and animation options
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires zoomstart
* @fires move
* @fires zoom
* @fires rotate
* @fires pitch
* @fires zoomend
* @fires moveend
* @returns {Map} `this`
*/
easeTo: function(options, eventData) {
this.stop();
options = util.extend({
offset: [0, 0],
duration: 500,
easing: util.ease
}, options);
var tr = this.transform,
offset = Point.convert(options.offset),
startZoom = this.getZoom(),
startBearing = this.getBearing(),
startPitch = this.getPitch(),
zoom = 'zoom' in options ? +options.zoom : startZoom,
bearing = 'bearing' in options ? this._normalizeBearing(options.bearing, startBearing) : startBearing,
pitch = 'pitch' in options ? +options.pitch : startPitch,
toLngLat,
toPoint;
if ('center' in options) {
toLngLat = LngLat.convert(options.center);
toPoint = tr.centerPoint.add(offset);
} else if ('around' in options) {
toLngLat = LngLat.convert(options.around);
toPoint = tr.locationPoint(toLngLat);
} else {
toPoint = tr.centerPoint.add(offset);
toLngLat = tr.pointLocation(toPoint);
}
var fromPoint = tr.locationPoint(toLngLat);
if (options.animate === false) options.duration = 0;
this.zooming = (zoom !== startZoom);
this.rotating = (startBearing !== bearing);
this.pitching = (pitch !== startPitch);
if (!options.noMoveStart) {
this.fire('movestart', eventData);
}
if (this.zooming) {
this.fire('zoomstart', eventData);
}
clearTimeout(this._onEaseEnd);
this._ease(function (k) {
if (this.zooming) {
tr.zoom = interpolate(startZoom, zoom, k);
}
if (this.rotating) {
tr.bearing = interpolate(startBearing, bearing, k);
}
if (this.pitching) {
tr.pitch = interpolate(startPitch, pitch, k);
}
tr.setLocationAtPoint(toLngLat, fromPoint.add(toPoint.sub(fromPoint)._mult(k)));
this.fire('move', eventData);
if (this.zooming) {
this.fire('zoom', eventData);
}
if (this.rotating) {
this.fire('rotate', eventData);
}
if (this.pitching) {
this.fire('pitch', eventData);
}
}, function() {
if (options.delayEndEvents) {
this._onEaseEnd = setTimeout(this._easeToEnd.bind(this, eventData), options.delayEndEvents);
} else {
this._easeToEnd(eventData);
}
}.bind(this), options);
return this;
},
_easeToEnd: function(eventData) {
if (this.zooming) {
this.fire('zoomend', eventData);
}
this.fire('moveend', eventData);
this.zooming = false;
this.rotating = false;
this.pitching = false;
},
/**
* Change any combination of center, zoom, bearing, and pitch, animated along a curve that
* evokes flight. The transition animation seamlessly incorporates zooming and panning to help
* the user find his or her bearings even after traversing a great distance.
*
* @param {CameraOptions|AnimationOptions} options map view and animation options
* @param {number} [options.curve=1.42] Relative amount of zooming that takes place along the
* flight path. A high value maximizes zooming for an exaggerated animation, while a low
* value minimizes zooming for something closer to {@link #Map.easeTo}. 1.42 is the average
* value selected by participants in the user study in
* [van Wijk (2003)](https://www.win.tue.nl/~vanwijk/zoompan.pdf). A value of
* `Math.pow(6, 0.25)` would be equivalent to the root mean squared average velocity. A
* value of 1 would produce a circular motion.
* @param {number} [options.minZoom] Zero-based zoom level at the peak of the flight path. If
* `options.curve` is specified, this option is ignored.
* @param {number} [options.speed=1.2] Average speed of the animation. A speed of 1.2 means that
* the map appears to move along the flight path by 1.2 times `options.curve` screenfuls every
* second. A _screenful_ is the visible span in pixels. It does not correspond to a fixed
* physical distance but rather varies by zoom level.
* @param {number} [options.screenSpeed] Average speed of the animation, measured in screenfuls
* per second, assuming a linear timing curve. If `options.speed` is specified, this option
* is ignored.
* @param {Function} [options.easing] Transition timing curve
* @param {EventData} [eventData] Data to propagate to any event receivers
* @fires movestart
* @fires zoomstart
* @fires move
* @fires zoom
* @fires rotate
* @fires pitch
* @fires zoomend
* @fires moveend
* @returns {this}
* @example
* // fly with default options to null island
* map.flyTo({center: [0, 0], zoom: 9});
* // using flyTo options
* map.flyTo({
* center: [0, 0],
* zoom: 9,
* speed: 0.2,
* curve: 1,
* easing: function(t) {
* return t;
* }
* });
*/
flyTo: function(options, eventData) {
// This method implements an “optimal path” animation, as detailed in:
//
// Van Wijk, Jarke J.; Nuij, Wim A. A. “Smooth and efficient zooming and panning.” INFOVIS
// ’03. pp. 15–22. <https://www.win.tue.nl/~vanwijk/zoompan.pdf#page=5>.
//
// Where applicable, local variable documentation begins with the associated variable or
// function in van Wijk (2003).
this.stop();
options = util.extend({
offset: [0, 0],
speed: 1.2,
curve: 1.42,
easing: util.ease
}, options);
var tr = this.transform,
offset = Point.convert(options.offset),
startZoom = this.getZoom(),
startBearing = this.getBearing(),
startPitch = this.getPitch();
var center = 'center' in options ? LngLat.convert(options.center) : this.getCenter();
var zoom = 'zoom' in options ? +options.zoom : startZoom;
var bearing = 'bearing' in options ? this._normalizeBearing(options.bearing, startBearing) : startBearing;
var pitch = 'pitch' in options ? +options.pitch : startPitch;
// If a path crossing the antimeridian would be shorter, extend the final coordinate so that
// interpolating between the two endpoints will cross it.
if (Math.abs(tr.center.lng) + Math.abs(center.lng) > 180) {
if (tr.center.lng > 0 && center.lng < 0) {
center.lng += 360;
} else if (tr.center.lng < 0 && center.lng > 0) {
center.lng -= 360;
}
}
var scale = tr.zoomScale(zoom - startZoom),
from = tr.point,
to = 'center' in options ? tr.project(center).sub(offset.div(scale)) : from;
var startWorldSize = tr.worldSize,
rho = options.curve,
// w₀: Initial visible span, measured in pixels at the initial scale.
w0 = Math.max(tr.width, tr.height),
// w₁: Final visible span, measured in pixels with respect to the initial scale.
w1 = w0 / scale,
// Length of the flight path as projected onto the ground plane, measured in pixels from
// the world image origin at the initial scale.
u1 = to.sub(from).mag();
if ('minZoom' in options) {
var minZoom = util.clamp(Math.min(options.minZoom, startZoom, zoom), tr.minZoom, tr.maxZoom);
// w<sub>m</sub>: Maximum visible span, measured in pixels with respect to the initial
// scale.
var wMax = w0 / tr.zoomScale(minZoom - startZoom);
rho = Math.sqrt(wMax / u1 * 2);
}
// ρ²
var rho2 = rho * rho;
/**
* rᵢ: Returns the zoom-out factor at one end of the animation.
*
* @param i 0 for the ascent or 1 for the descent.
* @private
*/
function r(i) {
var b = (w1 * w1 - w0 * w0 + (i ? -1 : 1) * rho2 * rho2 * u1 * u1) / (2 * (i ? w1 : w0) * rho2 * u1);
return Math.log(Math.sqrt(b * b + 1) - b);
}
function sinh(n) { return (Math.exp(n) - Math.exp(-n)) / 2; }
function cosh(n) { return (Math.exp(n) + Math.exp(-n)) / 2; }
function tanh(n) { return sinh(n) / cosh(n); }
// r₀: Zoom-out factor during ascent.
var r0 = r(0),
/**
* w(s): Returns the visible span on the ground, measured in pixels with respect to the
* initial scale.
*
* Assumes an angular field of view of 2 arctan ½ ≈ 53°.
* @private
*/
w = function (s) { return (cosh(r0) / cosh(r0 + rho * s)); },
/**
* u(s): Returns the distance along the flight path as projected onto the ground plane,
* measured in pixels from the world image origin at the initial scale.
* @private
*/
u = function (s) { return w0 * ((cosh(r0) * tanh(r0 + rho * s) - sinh(r0)) / rho2) / u1; },
// S: Total length of the flight path, measured in ρ-screenfuls.
S = (r(1) - r0) / rho;
// When u₀ = u₁, the optimal path doesn’t require both ascent and descent.
if (Math.abs(u1) < 0.000001) {
// Perform a more or less instantaneous transition if the path is too short.
if (Math.abs(w0 - w1) < 0.000001) return this.easeTo(options);
var k = w1 < w0 ? -1 : 1;
S = Math.abs(Math.log(w1 / w0)) / rho;
u = function() { return 0; };
w = function(s) { return Math.exp(k * rho * s); };
}
if ('duration' in options) {
options.duration = +options.duration;
} else {
var V = 'screenSpeed' in options ? +options.screenSpeed / rho : +options.speed;
options.duration = 1000 * S / V;
}
this.zooming = true;
if (startBearing !== bearing) this.rotating = true;
if (startPitch !== pitch) this.pitching = true;
this.fire('movestart', eventData);
this.fire('zoomstart', eventData);
this._ease(function (k) {
// s: The distance traveled along the flight path, measured in ρ-screenfuls.
var s = k * S,
us = u(s);
tr.zoom = startZoom + tr.scaleZoom(1 / w(s));
tr.center = tr.unproject(from.add(to.sub(from).mult(us)), startWorldSize);
if (this.rotating) {
tr.bearing = interpolate(startBearing, bearing, k);
}
if (this.pitching) {
tr.pitch = interpolate(startPitch, pitch, k);
}
this.fire('move', eventData);
this.fire('zoom', eventData);
if (this.rotating) {
this.fire('rotate', eventData);
}
if (this.pitching) {
this.fire('pitch', eventData);
}
}, function() {
this.fire('zoomend', eventData);
this.fire('moveend', eventData);
this.zooming = false;
this.rotating = false;
this.pitching = false;
}, options);
return this;
},
isEasing: function() {
return !!this._abortFn;
},
/**
* Stop current animation
*
* @returns {Map} `this`
*/
stop: function() {
if (this._abortFn) {
this._abortFn();
this._finishEase();
}
return this;
},
_ease: function(frame, finish, options) {
this._finishFn = finish;
this._abortFn = browser.timed(function (t) {
frame.call(this, options.easing(t));
if (t === 1) {
this._finishEase();
}
}, options.animate === false ? 0 : options.duration, this);
},
_finishEase: function() {
delete this._abortFn;
// The finish function might emit events which trigger new eases, which
// set a new _finishFn. Ensure we don't delete it unintentionally.
var finish = this._finishFn;
delete this._finishFn;
finish.call(this);
},
// convert bearing so that it's numerically close to the current one so that it interpolates properly
_normalizeBearing: function(bearing, currentBearing) {
bearing = util.wrap(bearing, -180, 180);
var diff = Math.abs(bearing - currentBearing);
if (Math.abs(bearing - 360 - currentBearing) < diff) bearing -= 360;
if (Math.abs(bearing + 360 - currentBearing) < diff) bearing += 360;
return bearing;
},
_updateEasing: function(duration, zoom, bezier) {
var easing;
if (this.ease) {
var ease = this.ease,
t = (Date.now() - ease.start) / ease.duration,
speed = ease.easing(t + 0.01) - ease.easing(t),
// Quick hack to make new bezier that is continuous with last
x = 0.27 / Math.sqrt(speed * speed + 0.0001) * 0.01,
y = Math.sqrt(0.27 * 0.27 - x * x);
easing = util.bezier(x, y, 0.25, 1);
} else {
easing = bezier ? util.bezier.apply(util, bezier) : util.ease;
}
// store information on current easing
this.ease = {
start: (new Date()).getTime(),
to: Math.pow(2, zoom),
duration: duration,
easing: easing
};
return easing;
}
});