devextreme/viz/vector_map/projection.main.js

HTML5 JavaScript Component Suite for Responsive Web Development

/**
 * DevExtreme (viz/vector_map/projection.main.js)
 * Version: 18.1.3
 * Build date: Tue May 15 2018
 *
 * Copyright (c) 2012 - 2018 Developer Express Inc. ALL RIGHTS RESERVED
 * Read about DevExtreme licensing here: https://js.devexpress.com/Licensing/
 */
"use strict";
var extend = require("../../core/utils/extend").extend,
    eventEmitterModule = require("./event_emitter");
var _Number = Number,
    _min = Math.min,
    _max = Math.max,
    _abs = Math.abs,
    _round = Math.round,
    _ln = Math.log,
    _pow = Math.pow,
    TWO_TO_LN2 = 2 / Math.LN2,
    MIN_BOUNDS_RANGE = 1 / 3600 / 180 / 10,
    DEFAULT_MIN_ZOOM = 1,
    DEFAULT_MAX_ZOOM = 256,
    DEFAULT_CENTER = [NaN, NaN],
    DEFAULT_ENGINE_NAME = "mercator";

function floatsEqual(f1, f2) {
    return _abs(f1 - f2) < 1e-8
}

function arraysEqual(a1, a2) {
    return floatsEqual(a1[0], a2[0]) && floatsEqual(a1[1], a2[1])
}

function parseAndClamp(value, minValue, maxValue, defaultValue) {
    var val = _Number(value);
    return isFinite(val) ? _min(_max(val, minValue), maxValue) : defaultValue
}

function parseAndClampArray(value, minValue, maxValue, defaultValue) {
    return [parseAndClamp(value[0], minValue[0], maxValue[0], defaultValue[0]), parseAndClamp(value[1], minValue[1], maxValue[1], defaultValue[1])]
}

function getEngine(engine) {
    return engine instanceof Engine && engine || projection.get(engine) || projection.get(DEFAULT_ENGINE_NAME)
}

function Projection(parameters) {
    var that = this;
    that._initEvents();
    that._params = parameters;
    that._engine = getEngine();
    that._center = that._engine.center();
    that._adjustCenter()
}
Projection.prototype = {
    constructor: Projection,
    _minZoom: DEFAULT_MIN_ZOOM,
    _maxZoom: DEFAULT_MAX_ZOOM,
    _zoom: DEFAULT_MIN_ZOOM,
    _center: DEFAULT_CENTER,
    _canvas: {},
    _scale: [],
    dispose: function() {
        this._disposeEvents()
    },
    setEngine: function(value) {
        var that = this,
            engine = getEngine(value);
        if (that._engine !== engine) {
            that._engine = engine;
            that._fire("engine");
            if (that._changeCenter(engine.center())) {
                that._triggerCenterChanged()
            }
            if (that._changeZoom(that._minZoom)) {
                that._triggerZoomChanged()
            }
            that._adjustCenter();
            that._setupScreen()
        }
    },
    setBounds: function(bounds) {
        if (void 0 !== bounds) {
            this.setEngine(this._engine.original().bounds(bounds))
        }
    },
    _setupScreen: function() {
        var that = this,
            canvas = that._canvas,
            width = canvas.width,
            height = canvas.height,
            aspectRatio = that._engine.ar();
        that._x0 = canvas.left + width / 2;
        that._y0 = canvas.top + height / 2;
        if (width / height <= aspectRatio) {
            that._xRadius = width / 2;
            that._yRadius = width / 2 / aspectRatio
        } else {
            that._xRadius = height / 2 * aspectRatio;
            that._yRadius = height / 2
        }
        that._fire("screen")
    },
    setSize: function(canvas) {
        var that = this;
        that._canvas = canvas;
        that._setupScreen()
    },
    _toScreen: function(coordinates) {
        return [this._x0 + this._xRadius * coordinates[0], this._y0 + this._yRadius * coordinates[1]]
    },
    _fromScreen: function(coordinates) {
        return [(coordinates[0] - this._x0) / this._xRadius, (coordinates[1] - this._y0) / this._yRadius]
    },
    _toTransformed: function(coordinates) {
        return [coordinates[0] * this._zoom + this._xCenter, coordinates[1] * this._zoom + this._yCenter]
    },
    _toTransformedFast: function(coordinates) {
        return [coordinates[0] * this._zoom, coordinates[1] * this._zoom]
    },
    _fromTransformed: function(coordinates) {
        return [(coordinates[0] - this._xCenter) / this._zoom, (coordinates[1] - this._yCenter) / this._zoom]
    },
    _adjustCenter: function() {
        var that = this,
            center = that._engine.project(that._center);
        that._xCenter = -center[0] * that._zoom || 0;
        that._yCenter = -center[1] * that._zoom || 0
    },
    project: function(coordinates) {
        return this._engine.project(coordinates)
    },
    transform: function(coordinates) {
        return this._toScreen(this._toTransformedFast(coordinates))
    },
    isInvertible: function() {
        return this._engine.isInvertible()
    },
    getSquareSize: function(size) {
        return [size[0] * this._zoom * this._xRadius, size[1] * this._zoom * this._yRadius]
    },
    getZoom: function() {
        return this._zoom
    },
    _changeZoom: function(value) {
        var that = this,
            oldZoom = that._zoom,
            newZoom = that._zoom = parseAndClamp(value, that._minZoom, that._maxZoom, that._minZoom),
            isChanged = !floatsEqual(oldZoom, newZoom);
        if (isChanged) {
            that._adjustCenter();
            that._fire("zoom")
        }
        return isChanged
    },
    setZoom: function(value) {
        if (this._engine.isInvertible() && this._changeZoom(value)) {
            this._triggerZoomChanged()
        }
    },
    getScaledZoom: function() {
        return _round((this._scale.length - 1) * _ln(this._zoom) / _ln(this._maxZoom))
    },
    setScaledZoom: function(scaledZoom) {
        this.setZoom(this._scale[_round(scaledZoom)])
    },
    changeScaledZoom: function(deltaZoom) {
        this.setZoom(this._scale[_max(_min(_round(this.getScaledZoom() + deltaZoom), this._scale.length - 1), 0)])
    },
    getZoomScalePartition: function() {
        return this._scale.length - 1
    },
    _setupScaling: function() {
        var step, zoom, that = this,
            k = _round(TWO_TO_LN2 * _ln(that._maxZoom)),
            i = 1;
        k = k > 4 ? k : 4;
        step = _pow(that._maxZoom, 1 / k);
        zoom = that._minZoom;
        that._scale = [zoom];
        for (; i <= k; ++i) {
            that._scale.push(zoom *= step)
        }
    },
    setMaxZoom: function(maxZoom) {
        var that = this;
        that._minZoom = DEFAULT_MIN_ZOOM;
        that._maxZoom = parseAndClamp(maxZoom, that._minZoom, _Number.MAX_VALUE, DEFAULT_MAX_ZOOM);
        that._setupScaling();
        if (that._zoom > that._maxZoom) {
            that.setZoom(that._maxZoom)
        }
        that._fire("max-zoom")
    },
    getCenter: function() {
        return this._center.slice()
    },
    setCenter: function(value) {
        if (this._engine.isInvertible() && this._changeCenter(value || [])) {
            this._triggerCenterChanged()
        }
    },
    _changeCenter: function(value) {
        var that = this,
            engine = that._engine,
            oldCenter = that._center,
            newCenter = that._center = parseAndClampArray(value, engine.min(), engine.max(), engine.center()),
            isChanged = !arraysEqual(oldCenter, newCenter);
        if (isChanged) {
            that._adjustCenter();
            that._fire("center")
        }
        return isChanged
    },
    _triggerCenterChanged: function() {
        this._params.centerChanged(this.getCenter())
    },
    _triggerZoomChanged: function() {
        this._params.zoomChanged(this.getZoom())
    },
    setCenterByPoint: function(coordinates, screenPosition) {
        var that = this,
            p = that._engine.project(coordinates),
            q = that._fromScreen(screenPosition);
        that.setCenter(that._engine.unproject([-q[0] / that._zoom + p[0], -q[1] / that._zoom + p[1]]))
    },
    beginMoveCenter: function() {
        if (this._engine.isInvertible()) {
            this._moveCenter = this._center
        }
    },
    endMoveCenter: function() {
        var that = this;
        if (that._moveCenter) {
            if (!arraysEqual(that._moveCenter, that._center)) {
                that._triggerCenterChanged()
            }
            that._moveCenter = null
        }
    },
    moveCenter: function(shift) {
        var current, center, that = this;
        if (that._moveCenter) {
            current = that._toScreen(that._toTransformed(that._engine.project(that._center)));
            center = that._engine.unproject(that._fromTransformed(that._fromScreen([current[0] + shift[0], current[1] + shift[1]])));
            that._changeCenter(center)
        }
    },
    getViewport: function() {
        var that = this,
            unproject = that._engine.unproject,
            lt = unproject(that._fromTransformed([-1, -1])),
            lb = unproject(that._fromTransformed([-1, 1])),
            rt = unproject(that._fromTransformed([1, -1])),
            rb = unproject(that._fromTransformed([1, 1])),
            minMax = findMinMax([selectFarthestPoint(lt[0], lb[0], rt[0], rb[0]), selectFarthestPoint(lt[1], rt[1], lb[1], rb[1])], [selectFarthestPoint(rt[0], rb[0], lt[0], lb[0]), selectFarthestPoint(lb[1], rb[1], lt[1], rt[1])]);
        return [].concat(minMax.min, minMax.max)
    },
    setViewport: function(viewport) {
        var engine = this._engine,
            data = viewport ? getZoomAndCenterFromViewport(engine.project, engine.unproject, viewport) : [this._minZoom, engine.center()];
        this.setZoom(data[0]);
        this.setCenter(data[1])
    },
    getTransform: function() {
        return {
            translateX: this._xCenter * this._xRadius,
            translateY: this._yCenter * this._yRadius
        }
    },
    fromScreenPoint: function(coordinates) {
        return this._engine.unproject(this._fromTransformed(this._fromScreen(coordinates)))
    },
    _eventNames: ["engine", "screen", "center", "zoom", "max-zoom"]
};
eventEmitterModule.makeEventEmitter(Projection);

function selectFarthestPoint(point1, point2, basePoint1, basePoint2) {
    var basePoint = (basePoint1 + basePoint2) / 2;
    return _abs(point1 - basePoint) > _abs(point2 - basePoint) ? point1 : point2
}

function selectClosestPoint(point1, point2, basePoint1, basePoint2) {
    var basePoint = (basePoint1 + basePoint2) / 2;
    return _abs(point1 - basePoint) < _abs(point2 - basePoint) ? point1 : point2
}

function getZoomAndCenterFromViewport(project, unproject, viewport) {
    var lt = project([viewport[0], viewport[3]]),
        lb = project([viewport[0], viewport[1]]),
        rt = project([viewport[2], viewport[3]]),
        rb = project([viewport[2], viewport[1]]),
        l = selectClosestPoint(lt[0], lb[0], rt[0], rb[0]),
        r = selectClosestPoint(rt[0], rb[0], lt[0], lb[0]),
        t = selectClosestPoint(lt[1], rt[1], lb[1], rb[1]),
        b = selectClosestPoint(lb[1], rb[1], lt[1], rt[1]);
    return [2 / _max(_abs(l - r), _abs(t - b)), unproject([(l + r) / 2, (t + b) / 2])]
}

function setMinMax(engine, p1, p2) {
    var minMax = findMinMax(p1, p2);
    engine.min = returnArray(minMax.min);
    engine.max = returnArray(minMax.max)
}

function Engine(parameters) {
    var that = this,
        project = createProjectMethod(parameters.to),
        unproject = parameters.from ? createUnprojectMethod(parameters.from) : returnValue(DEFAULT_CENTER);
    that.project = project;
    that.unproject = unproject;
    that.original = returnValue(that);
    that.source = function() {
        return extend({}, parameters)
    };
    that.isInvertible = returnValue(!!parameters.from);
    that.ar = returnValue(parameters.aspectRatio > 0 ? _Number(parameters.aspectRatio) : 1);
    that.center = returnArray(unproject([0, 0]));
    setMinMax(that, [unproject([-1, 0])[0], unproject([0, 1])[1]], [unproject([1, 0])[0], unproject([0, -1])[1]])
}
Engine.prototype.aspectRatio = function(aspectRatio) {
    var engine = new Engine(extend(this.source(), {
        aspectRatio: aspectRatio
    }));
    engine.original = this.original;
    engine.min = this.min;
    engine.max = this.max;
    return engine
};
Engine.prototype.bounds = function(bounds) {
    bounds = bounds || [];
    var engine, parameters = this.source(),
        min = this.min(),
        max = this.max(),
        b1 = parseAndClampArray([bounds[0], bounds[1]], min, max, min),
        b2 = parseAndClampArray([bounds[2], bounds[3]], min, max, max),
        p1 = parameters.to(b1),
        p2 = parameters.to(b2),
        delta = _min(_abs(p2[0] - p1[0]) > MIN_BOUNDS_RANGE ? _abs(p2[0] - p1[0]) : 2, _abs(p2[1] - p1[1]) > MIN_BOUNDS_RANGE ? _abs(p2[1] - p1[1]) : 2);
    if (delta < 2) {
        extend(parameters, createProjectUnprojectMethods(parameters.to, parameters.from, p1, p2, delta))
    }
    engine = new Engine(parameters);
    engine.original = this.original;
    setMinMax(engine, b1, b2);
    return engine
};

function isEngine(engine) {
    return engine instanceof Engine
}

function invertVerticalAxis(pair) {
    return [pair[0], -pair[1]]
}

function createProjectMethod(method) {
    return function(arg) {
        return invertVerticalAxis(method(arg))
    }
}

function createUnprojectMethod(method) {
    return function(arg) {
        return method(invertVerticalAxis(arg))
    }
}

function returnValue(value) {
    return function() {
        return value
    }
}

function returnArray(value) {
    return function() {
        return value.slice()
    }
}

function projection(parameters) {
    return parameters && parameters.to ? new Engine(parameters) : null
}

function findMinMax(p1, p2) {
    return {
        min: [_min(p1[0], p2[0]), _min(p1[1], p2[1])],
        max: [_max(p1[0], p2[0]), _max(p1[1], p2[1])]
    }
}
var projectionsCache = {};
projection.get = function(name) {
    return projectionsCache[name] || null
};
projection.add = function(name, engine) {
    if (!projectionsCache[name] && isEngine(engine)) {
        projectionsCache[name] = engine
    }
    return projection
};

function createProjectUnprojectMethods(project, unproject, p1, p2, delta) {
    var x0 = (p1[0] + p2[0]) / 2 - delta / 2,
        y0 = (p1[1] + p2[1]) / 2 - delta / 2,
        k = 2 / delta;
    return {
        to: function(coordinates) {
            var p = project(coordinates);
            return [-1 + (p[0] - x0) * k, -1 + (p[1] - y0) * k]
        },
        from: function(coordinates) {
            var p = [x0 + (coordinates[0] + 1) / k, y0 + (coordinates[1] + 1) / k];
            return unproject(p)
        }
    }
}
exports.Projection = Projection;
exports.projection = projection;