lottie-web/player/js/utils/text/TextSelectorProperty.js

After Effects plugin for exporting animations to SVG + JavaScript or canvas + JavaScript

import {
  extendPrototype,
} from '../functionExtensions';
import DynamicPropertyContainer from '../helpers/dynamicProperties';
import PropertyFactory from '../PropertyFactory';
import BezierFactory from '../../3rd_party/BezierEaser';

const TextSelectorProp = (function () {
  var max = Math.max;
  var min = Math.min;
  var floor = Math.floor;

  function TextSelectorPropFactory(elem, data) {
    this._currentTextLength = -1;
    this.k = false;
    this.data = data;
    this.elem = elem;
    this.comp = elem.comp;
    this.finalS = 0;
    this.finalE = 0;
    this.initDynamicPropertyContainer(elem);
    this.s = PropertyFactory.getProp(elem, data.s || { k: 0 }, 0, 0, this);
    if ('e' in data) {
      this.e = PropertyFactory.getProp(elem, data.e, 0, 0, this);
    } else {
      this.e = { v: 100 };
    }
    this.o = PropertyFactory.getProp(elem, data.o || { k: 0 }, 0, 0, this);
    this.xe = PropertyFactory.getProp(elem, data.xe || { k: 0 }, 0, 0, this);
    this.ne = PropertyFactory.getProp(elem, data.ne || { k: 0 }, 0, 0, this);
    this.sm = PropertyFactory.getProp(elem, data.sm || { k: 100 }, 0, 0, this);
    this.a = PropertyFactory.getProp(elem, data.a, 0, 0.01, this);
    if (!this.dynamicProperties.length) {
      this.getValue();
    }
  }

  TextSelectorPropFactory.prototype = {
    getMult: function (ind) {
      if (this._currentTextLength !== this.elem.textProperty.currentData.l.length) {
        this.getValue();
      }
      var x1 = 0;
      var y1 = 0;
      var x2 = 1;
      var y2 = 1;
      if (this.ne.v > 0) {
        x1 = this.ne.v / 100.0;
      } else {
        y1 = -this.ne.v / 100.0;
      }
      if (this.xe.v > 0) {
        x2 = 1.0 - this.xe.v / 100.0;
      } else {
        y2 = 1.0 + this.xe.v / 100.0;
      }
      var easer = BezierFactory.getBezierEasing(x1, y1, x2, y2).get;

      var mult = 0;
      var s = this.finalS;
      var e = this.finalE;
      var type = this.data.sh;
      if (type === 2) {
        if (e === s) {
          mult = ind >= e ? 1 : 0;
        } else {
          mult = max(0, min(0.5 / (e - s) + (ind - s) / (e - s), 1));
        }
        mult = easer(mult);
      } else if (type === 3) {
        if (e === s) {
          mult = ind >= e ? 0 : 1;
        } else {
          mult = 1 - max(0, min(0.5 / (e - s) + (ind - s) / (e - s), 1));
        }

        mult = easer(mult);
      } else if (type === 4) {
        if (e === s) {
          mult = 0;
        } else {
          mult = max(0, min(0.5 / (e - s) + (ind - s) / (e - s), 1));
          if (mult < 0.5) {
            mult *= 2;
          } else {
            mult = 1 - 2 * (mult - 0.5);
          }
        }
        mult = easer(mult);
      } else if (type === 5) {
        if (e === s) {
          mult = 0;
        } else {
          var tot = e - s;
          /* ind += 0.5;
                    mult = -4/(tot*tot)*(ind*ind)+(4/tot)*ind; */
          ind = min(max(0, ind + 0.5 - s), e - s);
          var x = -tot / 2 + ind;
          var a = tot / 2;
          mult = Math.sqrt(1 - (x * x) / (a * a));
        }
        mult = easer(mult);
      } else if (type === 6) {
        if (e === s) {
          mult = 0;
        } else {
          ind = min(max(0, ind + 0.5 - s), e - s);
          mult = (1 + (Math.cos((Math.PI + Math.PI * 2 * (ind) / (e - s))))) / 2; // eslint-disable-line
        }
        mult = easer(mult);
      } else {
        if (ind >= floor(s)) {
          if (ind - s < 0) {
            mult = max(0, min(min(e, 1) - (s - ind), 1));
          } else {
            mult = max(0, min(e - ind, 1));
          }
        }
        mult = easer(mult);
      }
      // Smoothness implementation.
      // The smoothness represents a reduced range of the original [0; 1] range.
      // if smoothness is 25%, the new range will be [0.375; 0.625]
      // Steps are:
      // - find the lower value of the new range (threshold)
      // - if multiplier is smaller than that value, floor it to 0
      // - if it is larger,
      //     - subtract the threshold
      //     - divide it by the smoothness (this will return the range to [0; 1])
      // Note: If it doesn't work on some scenarios, consider applying it before the easer.
      if (this.sm.v !== 100) {
        var smoothness = this.sm.v * 0.01;
        if (smoothness === 0) {
          smoothness = 0.00000001;
        }
        var threshold = 0.5 - smoothness * 0.5;
        if (mult < threshold) {
          mult = 0;
        } else {
          mult = (mult - threshold) / smoothness;
          if (mult > 1) {
            mult = 1;
          }
        }
      }
      return mult * this.a.v;
    },
    getValue: function (newCharsFlag) {
      this.iterateDynamicProperties();
      this._mdf = newCharsFlag || this._mdf;
      this._currentTextLength = this.elem.textProperty.currentData.l.length || 0;
      if (newCharsFlag && this.data.r === 2) {
        this.e.v = this._currentTextLength;
      }
      var divisor = this.data.r === 2 ? 1 : 100 / this.data.totalChars;
      var o = this.o.v / divisor;
      var s = this.s.v / divisor + o;
      var e = (this.e.v / divisor) + o;
      if (s > e) {
        var _s = s;
        s = e;
        e = _s;
      }
      this.finalS = s;
      this.finalE = e;
    },
  };
  extendPrototype([DynamicPropertyContainer], TextSelectorPropFactory);

  function getTextSelectorProp(elem, data, arr) {
    return new TextSelectorPropFactory(elem, data, arr);
  }

  return {
    getTextSelectorProp: getTextSelectorProp,
  };
}());

export default TextSelectorProp;