@rgsoft/turtle/dist/index.mjs

Turtle graphics and L-Systems library

// src/types.ts
var alphabetSymbols = ["F", "G", "H", "L", "M", "D", "U", "+", "-", "[", "]"];
var isValidAlphabetSymbol = (chr) => alphabetSymbols.includes(chr);

// src/rule.ts
var Rule = class {
  constructor(rule) {
    const matches = rule.replace(/\s/g, "").match(/^(.)(-|=)>(.+)$/);
    if (!matches) {
      throw new Error("Unrecognized rule pattern");
    }
    const base = matches[1];
    const next = matches[3];
    if (!isValidAlphabetSymbol(base)) {
      throw new Error(`Symbol '${base}' not recognized in condition`);
    }
    this._base = base;
    this._next = [];
    next.split("").forEach((c) => {
      if (!isValidAlphabetSymbol(c)) {
        throw new Error(`Symbol '${c}' not recognized in predicate`);
      }
      this._next.push(c);
    });
  }
  get base() {
    return this._base;
  }
  get next() {
    return this._next;
  }
  get nextString() {
    return this._next.join("");
  }
  toString() {
    return `${this.base} => ${this._next.join("")}`;
  }
};

// src/lsystem.ts
var LSystem = class {
  constructor(axiom, rules) {
    this._axiom = "";
    this._sentence = "";
    this._generation = 0;
    this.axiom = axiom;
    this._rules = rules.map((rule) => typeof rule === "string" ? new Rule(rule) : rule);
    this.init();
  }
  init() {
    this._sentence = this._axiom;
    this._generation = 0;
  }
  /**
   * 
   * @param { number } n 
   */
  generate(n = 1) {
    let nextGen;
    for (let i = 0; i < n; i++) {
      nextGen = "";
      this._sentence.split("").forEach((c) => {
        const rule = this._rules.find((r) => r.base === c);
        nextGen = nextGen.concat(rule === void 0 ? c : rule.nextString);
      });
      this._sentence = nextGen;
      this._generation++;
    }
  }
  get sentence() {
    return this._sentence;
  }
  get generation() {
    return this._generation;
  }
  get rules() {
    return [...this._rules];
  }
  set axiom(val) {
    val.split("").forEach((c) => {
      if (!isValidAlphabetSymbol(c)) {
        throw new Error(`Symbol '${c}' not recognized in axiom`);
      }
    });
    this._axiom = val;
    this.init();
  }
  get axiom() {
    return this._axiom;
  }
};

// src/turtle.ts
var Turtle = class {
  constructor(config) {
    this.config = config;
    /**
     * @type { number }
     */
    this.currentScale = 1;
    this.alphabetMap = {
      F: () => {
        const ctx = this.config.context;
        const lineWith = this.config.scale.scaleStrokeWeight ? this.config.strokeWeight * this.currentScale : this.config.strokeWeight;
        const lineSize = this.config.scale.scaleStrokeSize ? this.config.strokeSize * this.currentScale : this.config.strokeSize;
        ctx.beginPath();
        ctx.moveTo(0, 0);
        ctx.lineCap = "round";
        ctx.lineWidth = lineWith;
        ctx.lineTo(lineSize, 0);
        ctx.stroke();
        ctx.translate(lineSize, 0);
      },
      G: () => {
        const ctx = this.config.context;
        const lineWith = this.config.scale.scaleStrokeWeight ? this.config.strokeWeight * this.currentScale : this.config.strokeWeight;
        const lineSize = this.config.scale.scaleStrokeSize ? this.config.strokeSize * this.currentScale : this.config.strokeSize;
        ctx.beginPath();
        ctx.moveTo(0, 0);
        ctx.lineCap = "round";
        ctx.lineWidth = lineWith;
        ctx.lineTo(lineSize, 0);
        ctx.stroke();
        ctx.translate(lineSize, 0);
      },
      H: () => {
        const ctx = this.config.context;
        const lineWith = this.config.scale.scaleStrokeWeight ? this.config.strokeWeight * this.currentScale : this.config.strokeWeight;
        const lineSize = this.config.scale.scaleStrokeSize ? this.config.strokeSize * this.currentScale : this.config.strokeSize;
        ctx.beginPath();
        ctx.moveTo(0, 0);
        ctx.lineCap = "round";
        ctx.lineWidth = lineWith;
        ctx.lineTo(lineSize, 0);
        ctx.stroke();
        ctx.translate(lineSize, 0);
      },
      L: () => {
        const ctx = this.config.context;
        const lineWith = this.config.scale.scaleStrokeWeight ? this.config.strokeWeight * this.currentScale : this.config.strokeWeight;
        const lineSize = this.config.scale.scaleStrokeSize ? this.config.strokeSize * this.currentScale : this.config.strokeSize;
        ctx.beginPath();
        ctx.moveTo(0, 0);
        ctx.lineCap = "round";
        ctx.lineWidth = lineWith;
        ctx.arc(lineSize * 0.5, lineSize * 0.5, lineSize * Math.SQRT1_2, Math.PI * 1.25, Math.PI * 1.75);
        ctx.arc(lineSize * 0.5, -lineSize * 0.5, lineSize * Math.SQRT1_2, Math.PI * 0.25, Math.PI * 0.75);
        ctx.stroke();
      },
      M: () => {
        const lineSize = this.config.scale.scaleStrokeSize ? this.config.strokeSize * this.currentScale : this.config.strokeSize;
        this.config.context.translate(lineSize, 0);
      },
      D: () => this.currentScale *= this.config.scale.ratio,
      U: () => this.currentScale /= this.config.scale.ratio,
      "+": () => {
        const angle = this.config.scale.scaleAngle ? this.config.angle * this.currentScale : this.config.angle;
        this.config.context.rotate(angle);
      },
      "-": () => {
        const angle = this.config.scale.scaleAngle ? this.config.angle * this.currentScale : this.config.angle;
        this.config.context.rotate(-angle);
      },
      "[": () => this.config.context.save(),
      "]": () => this.config.context.restore()
    };
  }
  /**
   * 
   * @param { string } sentence 
   */
  render(sentence) {
    for (let i = 0; i < sentence.length; i++) {
      const chr = sentence[i];
      const fn = this.alphabetMap[chr];
      if (typeof fn === "function") {
        fn.call(this);
      }
    }
  }
  /**
   * 
   * @param { number } x 
   * @param { number } y 
   * @param { number } angle 
   */
  init(x, y, angle) {
    this.config.context.resetTransform();
    this.config.context.translate(x, y);
    this.config.context.rotate(angle);
    this.currentScale = 1;
  }
};
export {
  LSystem,
  Rule,
  Turtle
};
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