/*!
 * Signature Pad v3.0.0-beta.1 | https://github.com/szimek/signature_pad
 * (c) 2018 Szymon Nowak | Released under the MIT license
 */

(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
	typeof define === 'function' && define.amd ? define(factory) :
	(global.SignaturePad = factory());
}(this, (function () { 'use strict';

var Point = (function () {
    function Point(x, y, time) {
        this.x = x;
        this.y = y;
        this.time = time || Date.now();
    }
    Point.prototype.distanceTo = function (start) {
        return Math.sqrt(Math.pow(this.x - start.x, 2) + Math.pow(this.y - start.y, 2));
    };
    Point.prototype.equals = function (other) {
        return this.x === other.x && this.y === other.y && this.time === other.time;
    };
    Point.prototype.velocityFrom = function (start) {
        return (this.time !== start.time) ? this.distanceTo(start) / (this.time - start.time) : 0;
    };
    return Point;
}());

var Bezier = (function () {
    function Bezier(startPoint, control2, control1, endPoint, startWidth, endWidth) {
        this.startPoint = startPoint;
        this.control2 = control2;
        this.control1 = control1;
        this.endPoint = endPoint;
        this.startWidth = startWidth;
        this.endWidth = endWidth;
    }
    Bezier.fromPoints = function (points, widths) {
        var c2 = this.calculateControlPoints(points[0], points[1], points[2]).c2;
        var c3 = this.calculateControlPoints(points[1], points[2], points[3]).c1;
        return new Bezier(points[1], c2, c3, points[2], widths.start, widths.end);
    };
    Bezier.calculateControlPoints = function (s1, s2, s3) {
        var dx1 = s1.x - s2.x;
        var dy1 = s1.y - s2.y;
        var dx2 = s2.x - s3.x;
        var dy2 = s2.y - s3.y;
        var m1 = { x: (s1.x + s2.x) / 2.0, y: (s1.y + s2.y) / 2.0 };
        var m2 = { x: (s2.x + s3.x) / 2.0, y: (s2.y + s3.y) / 2.0 };
        var l1 = Math.sqrt((dx1 * dx1) + (dy1 * dy1));
        var l2 = Math.sqrt((dx2 * dx2) + (dy2 * dy2));
        var dxm = (m1.x - m2.x);
        var dym = (m1.y - m2.y);
        var k = l2 / (l1 + l2);
        var cm = { x: m2.x + (dxm * k), y: m2.y + (dym * k) };
        var tx = s2.x - cm.x;
        var ty = s2.y - cm.y;
        return {
            c1: new Point(m1.x + tx, m1.y + ty),
            c2: new Point(m2.x + tx, m2.y + ty)
        };
    };
    Bezier.prototype.length = function () {
        var steps = 10;
        var length = 0;
        var px;
        var py;
        for (var i = 0; i <= steps; i += 1) {
            var t = i / steps;
            var cx = this.point(t, this.startPoint.x, this.control1.x, this.control2.x, this.endPoint.x);
            var cy = this.point(t, this.startPoint.y, this.control1.y, this.control2.y, this.endPoint.y);
            if (i > 0) {
                var xdiff = cx - px;
                var ydiff = cy - py;
                length += Math.sqrt((xdiff * xdiff) + (ydiff * ydiff));
            }
            px = cx;
            py = cy;
        }
        return length;
    };
    Bezier.prototype.point = function (t, start, c1, c2, end) {
        return (start * (1.0 - t) * (1.0 - t) * (1.0 - t))
            + (3.0 * c1 * (1.0 - t) * (1.0 - t) * t)
            + (3.0 * c2 * (1.0 - t) * t * t)
            + (end * t * t * t);
    };
    return Bezier;
}());

function throttle(fn, wait) {
    if (wait === void 0) { wait = 250; }
    var previous = 0;
    var timeout = null;
    var result;
    var storedContext;
    var storedArgs;
    var later = function () {
        previous = Date.now();
        timeout = null;
        result = fn.apply(storedContext, storedArgs);
        if (!timeout) {
            storedContext = null;
            storedArgs = [];
        }
    };
    return function () {
        var args = [];
        for (var _i = 0; _i < arguments.length; _i++) {
            args[_i] = arguments[_i];
        }
        var now = Date.now();
        var remaining = wait - (now - previous);
        storedContext = this;
        storedArgs = args;
        if (remaining <= 0 || remaining > wait) {
            if (timeout) {
                clearTimeout(timeout);
                timeout = null;
            }
            previous = now;
            result = fn.apply(storedContext, storedArgs);
            if (!timeout) {
                storedContext = null;
                storedArgs = [];
            }
        }
        else if (!timeout) {
            timeout = setTimeout(later, remaining);
        }
        return result;
    };
}

var SignaturePad = (function () {
    function SignaturePad(canvas, options) {
        if (options === void 0) { options = {}; }
        var _this = this;
        this.canvas = canvas;
        this.options = options;
        this.velocityFilterWeight = options.velocityFilterWeight || 0.7;
        this.minWidth = options.minWidth || 0.5;
        this.maxWidth = options.maxWidth || 2.5;
        this.throttle = ("throttle" in options ? options.throttle : 16);
        this.minDistance = ("minDistance" in options ? options.minDistance : 5);
        if (this.throttle) {
            this._strokeMoveUpdate = throttle(SignaturePad.prototype._strokeUpdate, this.throttle);
        }
        else {
            this._strokeMoveUpdate = SignaturePad.prototype._strokeUpdate;
        }
        this.dotSize = options.dotSize || function () {
            return (this.minWidth + this.maxWidth) / 2;
        };
        this.penColor = options.penColor || "black";
        this.backgroundColor = options.backgroundColor || "rgba(0,0,0,0)";
        this.onBegin = options.onBegin;
        this.onEnd = options.onEnd;
        this._ctx = canvas.getContext("2d");
        this.clear();
        this._handleMouseDown = function (event) {
            if (event.which === 1) {
                _this._mouseButtonDown = true;
                _this._strokeBegin(event);
            }
        };
        this._handleMouseMove = function (event) {
            if (_this._mouseButtonDown) {
                _this._strokeMoveUpdate(event);
            }
        };
        this._handleMouseUp = function (event) {
            if (event.which === 1 && _this._mouseButtonDown) {
                _this._mouseButtonDown = false;
                _this._strokeEnd(event);
            }
        };
        this._handleTouchStart = function (event) {
            event.preventDefault();
            if (event.targetTouches.length === 1) {
                var touch = event.changedTouches[0];
                _this._strokeBegin(touch);
            }
        };
        this._handleTouchMove = function (event) {
            event.preventDefault();
            var touch = event.targetTouches[0];
            _this._strokeMoveUpdate(touch);
        };
        this._handleTouchEnd = function (event) {
            var wasCanvasTouched = event.target === _this.canvas;
            if (wasCanvasTouched) {
                event.preventDefault();
                var touch = event.targetTouches[0];
                _this._strokeEnd(touch);
            }
        };
        this.on();
    }
    SignaturePad.prototype.clear = function () {
        var ctx = this._ctx;
        var canvas = this.canvas;
        ctx.fillStyle = this.backgroundColor;
        ctx.clearRect(0, 0, canvas.width, canvas.height);
        ctx.fillRect(0, 0, canvas.width, canvas.height);
        this._data = [];
        this._reset();
        this._isEmpty = true;
    };
    SignaturePad.prototype.fromDataURL = function (dataUrl, options) {
        var _this = this;
        if (options === void 0) { options = {}; }
        var image = new Image();
        var ratio = options.ratio || window.devicePixelRatio || 1;
        var width = options.width || (this.canvas.width / ratio);
        var height = options.height || (this.canvas.height / ratio);
        this._reset();
        image.src = dataUrl;
        image.onload = function () {
            _this._ctx.drawImage(image, 0, 0, width, height);
        };
        this._isEmpty = false;
    };
    SignaturePad.prototype.toDataURL = function (type, encoderOptions) {
        switch (type) {
            case "image/svg+xml":
                return this._toSVG();
            default:
                return this.canvas.toDataURL(type, encoderOptions);
        }
    };
    SignaturePad.prototype.on = function () {
        this._handleMouseEvents();
        this._handleTouchEvents();
    };
    SignaturePad.prototype.off = function () {
        this.canvas.style.msTouchAction = "auto";
        this.canvas.style.touchAction = "auto";
        this.canvas.removeEventListener("mousedown", this._handleMouseDown);
        this.canvas.removeEventListener("mousemove", this._handleMouseMove);
        document.removeEventListener("mouseup", this._handleMouseUp);
        this.canvas.removeEventListener("touchstart", this._handleTouchStart);
        this.canvas.removeEventListener("touchmove", this._handleTouchMove);
        this.canvas.removeEventListener("touchend", this._handleTouchEnd);
    };
    SignaturePad.prototype.isEmpty = function () {
        return this._isEmpty;
    };
    SignaturePad.prototype.fromData = function (pointGroups) {
        var _this = this;
        this.clear();
        this._fromData(pointGroups, function (_a) {
            var color = _a.color, curve = _a.curve;
            return _this._drawCurve({ color: color, curve: curve });
        }, function (_a) {
            var color = _a.color, point = _a.point;
            return _this._drawDot({ color: color, point: point });
        });
        this._data = pointGroups;
    };
    SignaturePad.prototype.toData = function () {
        return this._data;
    };
    SignaturePad.prototype._strokeBegin = function (event) {
        var newPointGroup = {
            color: this.penColor,
            points: []
        };
        this._data.push(newPointGroup);
        this._reset();
        this._strokeUpdate(event);
        if (typeof this.onBegin === "function") {
            this.onBegin(event);
        }
    };
    SignaturePad.prototype._strokeUpdate = function (event) {
        var x = event.clientX;
        var y = event.clientY;
        var point = this._createPoint(x, y);
        var lastPointGroup = this._data[this._data.length - 1];
        var lastPoints = lastPointGroup.points;
        var lastPoint = lastPoints.length > 0 && lastPoints[lastPoints.length - 1];
        var isLastPointTooClose = lastPoint ? point.distanceTo(lastPoint) <= this.minDistance : false;
        var color = lastPointGroup.color;
        if (!lastPoint || !(lastPoint && isLastPointTooClose)) {
            var curve = this._addPoint(point);
            if (!lastPoint) {
                this._drawDot({ color: color, point: point });
            }
            else if (curve) {
                this._drawCurve({ color: color, curve: curve });
            }
            lastPoints.push({
                time: point.time,
                x: point.x,
                y: point.y
            });
        }
    };
    SignaturePad.prototype._strokeEnd = function (event) {
        this._strokeUpdate(event);
        if (typeof this.onEnd === "function") {
            this.onEnd(event);
        }
    };
    SignaturePad.prototype._handleMouseEvents = function () {
        this._mouseButtonDown = false;
        this.canvas.addEventListener("mousedown", this._handleMouseDown);
        this.canvas.addEventListener("mousemove", this._handleMouseMove);
        document.addEventListener("mouseup", this._handleMouseUp);
    };
    SignaturePad.prototype._handleTouchEvents = function () {
        this.canvas.style.msTouchAction = "none";
        this.canvas.style.touchAction = "none";
        this.canvas.addEventListener("touchstart", this._handleTouchStart);
        this.canvas.addEventListener("touchmove", this._handleTouchMove);
        this.canvas.addEventListener("touchend", this._handleTouchEnd);
    };
    SignaturePad.prototype._reset = function () {
        this._points = [];
        this._lastVelocity = 0;
        this._lastWidth = (this.minWidth + this.maxWidth) / 2;
        this._ctx.fillStyle = this.penColor;
    };
    SignaturePad.prototype._createPoint = function (x, y) {
        var rect = this.canvas.getBoundingClientRect();
        return new Point(x - rect.left, y - rect.top, new Date().getTime());
    };
    SignaturePad.prototype._addPoint = function (point) {
        var _points = this._points;
        _points.push(point);
        if (_points.length > 2) {
            if (_points.length === 3) {
                _points.unshift(_points[0]);
            }
            var widths = this._calculateCurveWidths(_points[1], _points[2]);
            var curve = Bezier.fromPoints(_points, widths);
            _points.shift();
            return curve;
        }
        return null;
    };
    SignaturePad.prototype._calculateCurveWidths = function (startPoint, endPoint) {
        var velocity = (this.velocityFilterWeight * endPoint.velocityFrom(startPoint))
            + ((1 - this.velocityFilterWeight) * this._lastVelocity);
        var newWidth = this._strokeWidth(velocity);
        var widths = {
            end: newWidth,
            start: this._lastWidth
        };
        this._lastVelocity = velocity;
        this._lastWidth = newWidth;
        return widths;
    };
    SignaturePad.prototype._strokeWidth = function (velocity) {
        return Math.max(this.maxWidth / (velocity + 1), this.minWidth);
    };
    SignaturePad.prototype._drawCurveSegment = function (x, y, width) {
        var ctx = this._ctx;
        ctx.moveTo(x, y);
        ctx.arc(x, y, width, 0, 2 * Math.PI, false);
        this._isEmpty = false;
    };
    SignaturePad.prototype._drawCurve = function (_a) {
        var color = _a.color, curve = _a.curve;
        var ctx = this._ctx;
        var widthDelta = curve.endWidth - curve.startWidth;
        var drawSteps = Math.floor(curve.length()) * 2;
        ctx.beginPath();
        ctx.fillStyle = color;
        for (var i = 0; i < drawSteps; i += 1) {
            var t = i / drawSteps;
            var tt = t * t;
            var ttt = tt * t;
            var u = 1 - t;
            var uu = u * u;
            var uuu = uu * u;
            var x = uuu * curve.startPoint.x;
            x += 3 * uu * t * curve.control1.x;
            x += 3 * u * tt * curve.control2.x;
            x += ttt * curve.endPoint.x;
            var y = uuu * curve.startPoint.y;
            y += 3 * uu * t * curve.control1.y;
            y += 3 * u * tt * curve.control2.y;
            y += ttt * curve.endPoint.y;
            var width = curve.startWidth + (ttt * widthDelta);
            this._drawCurveSegment(x, y, width);
        }
        ctx.closePath();
        ctx.fill();
    };
    SignaturePad.prototype._drawDot = function (_a) {
        var color = _a.color, point = _a.point;
        var ctx = this._ctx;
        var width = typeof this.dotSize === "function" ? this.dotSize() : this.dotSize;
        ctx.beginPath();
        this._drawCurveSegment(point.x, point.y, width);
        ctx.closePath();
        ctx.fillStyle = color;
        ctx.fill();
    };
    SignaturePad.prototype._fromData = function (pointGroups, drawCurve, drawDot) {
        for (var _i = 0, pointGroups_1 = pointGroups; _i < pointGroups_1.length; _i++) {
            var group = pointGroups_1[_i];
            var color = group.color, points = group.points;
            if (points.length > 1) {
                for (var j = 0; j < points.length; j += 1) {
                    var basicPoint = points[j];
                    var point = new Point(basicPoint.x, basicPoint.y, basicPoint.time);
                    this.penColor = color;
                    if (j === 0) {
                        this._reset();
                    }
                    var curve = this._addPoint(point);
                    if (curve) {
                        drawCurve({ color: color, curve: curve });
                    }
                }
            }
            else {
                this._reset();
                drawDot({
                    color: color,
                    point: points[0]
                });
            }
        }
    };
    SignaturePad.prototype._toSVG = function () {
        var _this = this;
        var pointGroups = this._data;
        var ratio = Math.max(window.devicePixelRatio || 1, 1);
        var minX = 0;
        var minY = 0;
        var maxX = this.canvas.width / ratio;
        var maxY = this.canvas.height / ratio;
        var svg = document.createElementNS("http://www.w3.org/2000/svg", "svg");
        svg.setAttribute("width", this.canvas.width.toString());
        svg.setAttribute("height", this.canvas.height.toString());
        this._fromData(pointGroups, function (_a) {
            var color = _a.color, curve = _a.curve;
            var path = document.createElement("path");
            if (!isNaN(curve.control1.x) &&
                !isNaN(curve.control1.y) &&
                !isNaN(curve.control2.x) &&
                !isNaN(curve.control2.y)) {
                var attr = "M " + curve.startPoint.x.toFixed(3) + "," + curve.startPoint.y.toFixed(3) + " "
                    + ("C " + curve.control1.x.toFixed(3) + "," + curve.control1.y.toFixed(3) + " ")
                    + (curve.control2.x.toFixed(3) + "," + curve.control2.y.toFixed(3) + " ")
                    + (curve.endPoint.x.toFixed(3) + "," + curve.endPoint.y.toFixed(3));
                path.setAttribute("d", attr);
                path.setAttribute("stroke-width", (curve.endWidth * 2.25).toFixed(3));
                path.setAttribute("stroke", color);
                path.setAttribute("fill", "none");
                path.setAttribute("stroke-linecap", "round");
                svg.appendChild(path);
            }
        }, function (_a) {
            var color = _a.color, point = _a.point;
            var circle = document.createElement("circle");
            var dotSize = typeof _this.dotSize === "function" ? _this.dotSize() : _this.dotSize;
            circle.setAttribute("r", dotSize.toString());
            circle.setAttribute("cx", point.x.toString());
            circle.setAttribute("cy", point.y.toString());
            circle.setAttribute("fill", color);
            svg.appendChild(circle);
        });
        var prefix = "data:image/svg+xml;base64,";
        var header = "<svg"
            + " xmlns=\"http://www.w3.org/2000/svg\""
            + " xmlns:xlink=\"http://www.w3.org/1999/xlink\""
            + (" viewBox=\"" + minX + " " + minY + " " + maxX + " " + maxY + "\"")
            + (" width=\"" + maxX + "\"")
            + (" height=\"" + maxY + "\"")
            + ">";
        var body = svg.innerHTML;
        if (body === undefined) {
            var dummy = document.createElement("dummy");
            var nodes = svg.childNodes;
            dummy.innerHTML = "";
            for (var i = 0; i < nodes.length; i += 1) {
                dummy.appendChild(nodes[i].cloneNode(true));
            }
            body = dummy.innerHTML;
        }
        var footer = "</svg>";
        var data = header + body + footer;
        return prefix + btoa(data);
    };
    return SignaturePad;
}());

return SignaturePad;

})));
