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synced 2025-09-21 04:27:56 +08:00
merged jfollas's new TextPath shape, and moved non-primative shapes to the plugins folder as shape plugins
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281
src/plugins/shapes/TextPath.js
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281
src/plugins/shapes/TextPath.js
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///////////////////////////////////////////////////////////////////////
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// Text Path
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///////////////////////////////////////////////////////////////////////
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/**
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* Path constructor.
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* @author Jason Follas
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* @constructor
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* @augments Kinetic.Path
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* @param {Object} config
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*/
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Kinetic.TextPath = Kinetic.Path.extend({
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init: function(config) {
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this.setDefaultAttrs({
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fontFamily: 'Calibri',
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fontSize: 12,
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fontStyle: 'normal',
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detectionType: 'path',
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text: ''
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});
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this.dummyCanvas = document.createElement('canvas');
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this.shapeType = "TextPath";
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var that = this;
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config.drawFunc = function(context) {
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var charArr = this.charArr;
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context.font = this.attrs.fontStyle + ' ' + this.attrs.fontSize + 'pt ' + this.attrs.fontFamily;
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context.textBaseline = 'middle';
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context.textAlign = 'left';
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context.save();
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var glyphInfo = this.glyphInfo;
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for (var i=0; i < glyphInfo.length; i++)
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{
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context.save();
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var p0 = glyphInfo[i].p0;
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var p1 = glyphInfo[i].p1;
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var ht = parseFloat(this.attrs.fontSize);
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context.translate(p0.x, p0.y);
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context.rotate(glyphInfo[i].rotation);
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this.fillText(context, glyphInfo[i].text);
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this.strokeText(context, glyphInfo[i].text);
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context.restore();
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//// To assist with debugging visually, uncomment following
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// context.beginPath();
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// if (i % 2)
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// context.strokeStyle = 'cyan';
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// else
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// context.strokeStyle = 'green';
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// context.moveTo(p0.x, p0.y);
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// context.lineTo(p1.x, p1.y);
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// context.stroke();
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}
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context.restore();
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};
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// call super constructor
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this._super(config);
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// update text data for certain attr changes
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var attrs = ['padding', 'text', 'textStroke', 'textStrokeWidth'];
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for(var n = 0; n < attrs.length; n++) {
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var attr = attrs[n];
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this.on(attr + 'Change', that._setTextData);
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}
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that._setTextData();
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},
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/**
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* get text width in pixels
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*/
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getTextWidth: function() {
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return this.textWidth;
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},
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/**
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* get text height in pixels
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*/
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getTextHeight: function() {
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return this.textHeight;
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},
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_getTextSize: function(text) {
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var dummyCanvas = this.dummyCanvas;
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var context = dummyCanvas.getContext('2d');
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context.save();
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context.font = this.attrs.fontStyle + ' ' + this.attrs.fontSize + 'pt ' + this.attrs.fontFamily;
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var metrics = context.measureText(text);
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context.restore();
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return {
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width: metrics.width,
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height: parseInt(this.attrs.fontSize, 10)
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};
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},
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/**
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* set text data.
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*/
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_setTextData: function() {
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var that = this;
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var size = this._getTextSize(this.attrs.text);
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this.textWidth = size.width;
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this.textHeight = size.height;
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this.glyphInfo = [];
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var charArr = this.attrs.text.split('');
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var p0 = undefined;
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var p1 = undefined;
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var pathCmd = undefined;
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var pIndex = -1;
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var currentT = 0;
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var getNextPathSegment = function() {
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currentT = 0;
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var pathData = that.dataArray;
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for (var i = pIndex + 1; i < pathData.length; i++) {
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if (pathData[i].pathLength > 0) {
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pIndex = i;
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return pathData[i];
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}
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else if (pathData[i].command == 'M') {
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p0 = {x: pathData[i].points[0], y: pathData[i].points[1]};
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}
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}
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return {};
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}
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var findSegmentToFitCharacter = function(c, before) {
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var glyphWidth = that._getTextSize(c).width;
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var currLen = 0;
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var attempts = 0;
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var needNextSegment = false;
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p1 = undefined;
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while (Math.abs(glyphWidth - currLen) / glyphWidth > 0.01 && attempts < 25) {
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attempts++;
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var cumulativePathLength = currLen;
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while (pathCmd === undefined) {
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pathCmd = getNextPathSegment();
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if (pathCmd && cumulativePathLength + pathCmd.pathLength < glyphWidth)
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{
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cumulativePathLength += pathCmd.pathLength;
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pathCmd = undefined;
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}
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}
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if (pathCmd === {} || p0 === undefined)
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return undefined;
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var needNewSegment = false;
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switch(pathCmd.command) {
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case 'L':
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if (that._getLineLength(p0.x, p0.y, pathCmd.points[0], pathCmd.points[1]) > glyphWidth)
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{
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p1 = that._getPointOnLine(glyphWidth, p0.x, p0.y, pathCmd.points[0], pathCmd.points[1], p0.x, p0.y);
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}
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else
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pathCmd = undefined;
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break;
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case 'A':
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var start = pathCmd.points[4]; // 4 = theta
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var dTheta = pathCmd.points[5];// 5 = dTheta
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var end = pathCmd.points[4] + dTheta;
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if (currentT == 0)
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currentT = start + 0.00000001; // Just in case start is 0
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else if (glyphWidth > currLen)
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currentT += (Math.PI / 180.0) * dTheta / Math.abs(dTheta);
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else
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currentT -= Math.PI / 360.0 * dTheta / Math.abs(dTheta);
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if (Math.abs(currentT) > Math.abs(end)) {
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currentT = end;
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needNewSegment = true;
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}
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p1 = that._getPointOnEllipticalArc(pathCmd.points[0], pathCmd.points[1], pathCmd.points[2], pathCmd.points[3], currentT, pathCmd.points[6]);
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break;
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case 'C':
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if (currentT == 0) {
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if (glyphWidth > pathCmd.pathLength)
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currentT = 0.00000001;
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else
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currentT = glyphWidth / pathCmd.pathLength;
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}
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else if (glyphWidth > currLen)
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currentT += (glyphWidth - currLen) / pathCmd.pathLength;
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else
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currentT -= (currLen - glyphWidth) / pathCmd.pathLength;
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if (currentT > 1.0) {
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currentT = 1.0;
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needNewSegment = true;
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}
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p1 = that._getPointOnCubicBezier(currentT, pathCmd.start.x, pathCmd.start.y, pathCmd.points[0], pathCmd.points[1], pathCmd.points[2], pathCmd.points[3], pathCmd.points[4], pathCmd.points[5])
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break;
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case 'Q':
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if (currentT == 0)
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currentT = glyphWidth / pathCmd.pathLength;
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else if (glyphWidth > currLen)
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currentT += (glyphWidth - currLen) / pathCmd.pathLength;
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else
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currentT -= (currLen - glyphWidth) / pathCmd.pathLength;
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if (currentT > 1.0) {
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currentT = 1.0;
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needNewSegment = true;
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}
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p1 = that._getPointOnQuadraticBezier(currentT, pathCmd.start.x, pathCmd.start.y, pathCmd.points[0], pathCmd.points[1], pathCmd.points[2], pathCmd.points[3])
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break;
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}
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if (p1 !== undefined)
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{
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currLen = that._getLineLength(p0.x, p0.y, p1.x, p1.y);
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}
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if (needNewSegment) {
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needNewSegment = false;
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pathCmd = undefined;
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}
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}
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}
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for (var i=0; i < charArr.length; i++) {
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// Find p1 such that line segment between p0 and p1 is approx. width of glyph
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findSegmentToFitCharacter(charArr[i]);
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if (p0 === undefined || p1 === undefined)
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break;
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var width = this._getLineLength(p0.x, p0.y, p1.x, p1.y);
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// Note: Since glyphs are rendered one at a time, any kerning pair data built into the font will not be used.
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// Can foresee having a rough pair table built in that the developer can override as needed.
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var kern = 0; // placeholder for future implementation
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var midpoint = this._getPointOnLine(kern + width / 2.0, p0.x, p0.y, p1.x, p1.y);
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var rotation = Math.atan2((p1.y - p0.y),(p1.x - p0.x));
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this.glyphInfo.push({ transposeX: midpoint.x, transposeY: midpoint.y, text: charArr[i], rotation: rotation, p0:p0, p1:p1});
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p0 = p1;
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}
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}
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});
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// add setters and getters
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Kinetic.Node.addGettersSetters(Kinetic.TextPath, ['fontFamily', 'fontSize', 'fontStyle', 'textFill', 'textStroke', 'textStrokeWidth', 'text']);
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