Another noise field
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// You can find the Turtle API reference here: https://turtletoy.net/syntax Canvas.setpenopacity(0.5); const size = 95; //min = 10, max = 100, step = 5 const perlinSize = 3; //min = 1, max = 50, step = 1 const turnRatio = 0.5; //min = 0.1, max = 5, step = 0.1 const footStep = 0.1; //min = 0.1, max = 2, step = 0.1 //const drawBoth = 2; //min = 0, max = 2, step = 1,(no, yes, middle) // Global code will be evaluated once. const turtle = new Turtle(); class Perlin{ constructor(size, gridSize){ this.size = size; this.gridSize = gridSize; this.grid = []; // For each grid intersection, compute a random unit vector for(let i = 0; i <= gridSize; i++){ let table = []; for(let j = 0; j <= gridSize; j++){ let angle = Math.random() * 2 * Math.PI; let x = Math.cos(angle); let y = Math.sin(angle); table.push([x, y]); // console.log([x, y]); } this.grid.push(table); } // console.log(this.grid); } get(x, y){ x = x / 2 + this.size / 2; y = y / 2 + this.size / 2; if(x < 0) x = 0; if(x >= this.size) x = this.size - 0.01; if(y < 0) y = 0; if(y >= this.size) y = this.size - 0.01; // console.log(x, y); let posx = x * this.gridSize / this.size; let posy = y * this.gridSize / this.size; // console.log(posx, posy); let x1 = Math.floor(posx); let x2 = x1 + 1; let y1 = Math.floor(posy); let y2 = y1 + 1; let scal = []; scal.push() scal.push(this.scalar(posx, posy, x1, y1)); scal.push(this.scalar(posx, posy, x2, y1)); scal.push(this.scalar(posx, posy, x1, y2)); scal.push(this.scalar(posx, posy, x2, y2)); // console.log(scal); // interpolate : linear interpolation for a start let int1 = this.interpolate(posx - x1, scal[0], scal[1]); let int2 = this.interpolate(posx - x1, scal[2], scal[3]); // console.log(int1, int2); return this.interpolate(posy - y1, int1, int2); } scalar(x, y, vx, vy){ x -= vx; y -= vy; // console.log(x, y); return x * this.grid[vx][vy][0] + y * this.grid[vx][vy][1]; } smooth(v){ if(v < 0) v = 0; if(v > 1) v = 1; return v**2 * (3 - 2*v); } interpolate(x, a, b){ return a + (b - a) * this.smooth(x) } } let perlin = new Perlin(size, perlinSize); let posx = 0; let posy = 0; let gen = 0; let step = 0; // The walk function will be called until it returns false. function walk(i) { if(Math.abs(posx) > size || Math.abs(posy) > size){ step++; posx = 0; posy = 0; turtle.seth(step); turtle.jump(posx, posy); gen++; if(step == 360) return false; } let turn = perlin.get(posx, posy) // console.log(amp); turtle.right(turn * turnRatio); turtle.forward(footStep); posx = turtle.x(); posy = turtle.y(); // console.log(posx, posy); return true; }