Rotating Image between 2 angles in Javascript using p5.js

Question

I want to rotate my image between cos(20) and -cos(20) with a smooth animation.

The tree is done recursively with branch() function. I can't figure out how to do it with loops. Is there a built in function or a specific algorithm to do so?

let angles = 0;
  var strokeValue = 1;
  function setup() {
    const canvas = createCanvas(540, 400);
    frameRate(8);
  }
 
  function draw() {
    background(220);
    angle = PI/8;
    translate(250, height);
    // I think the rotate function should be here
    branch(90); 
  }

  function branch(length) {
    strokeWeight(strokeValue);
    line(1, 1, 1, -length);
    translate(0, -length);
    if (length > 4) {
      //Right branches
      push();
      rotate(angle);
      branch(length * 0.72);
      pop();
      // left branches
      push();
      rotate(-angle);
      branch(length * 0.72);
      pop();
      push();
      // middle
      rotate(-angle * 0.2);
      branch(length * 0.3);
      pop();
    } 
  }

<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.4.0/p5.min.js"></script>

This is the picture

Nice tree you got there, is that a fractal tree ? because it sure looks like one [https://progur.com/2016/10/procedural-generation-create-fractal-trees-javascript.html](https://progur.com/2016/10/procedural-generation-create-fractal-trees-javascript.html) — darklightcode, Oct 19 '21 at 17:57

score 1 · Accepted Answer · edited Oct 19 '21 at 18:02

I tried this, though I'm not sure it's what you asked for so feel free to comment.

let angles = 0;
  var strokeValue = 1;
  function setup() {
    const canvas = createCanvas(540, 400);
    frameRate(30);
  }
 
  function draw() {
    background(220);
    angle = PI/8;
    translate(250, height);
    // I think the rotate function should be here
    rotate(cos(map(frameCount / 10,0,100,-20,20)));
    branch(90); 
  }

  function branch(length) {
    strokeWeight(strokeValue);
    line(1, 1, 1, -length);
    translate(0, -length);
    if (length > 4) {
      //Right branches
      push();
      rotate(angle);
      branch(length * 0.72);
      pop();
      // left branches
      push();
      rotate(-angle);
      branch(length * 0.72);
      pop();
      push();
      // middle
      rotate(-angle * 0.2);
      branch(length * 0.3);
      pop();
    } 
  }

<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.4.0/p5.min.js"></script>

Thank you, it works although it's not as smooth as I want it. — Yassine Mrabet, Oct 20 '21 at 10:19

Rotating Image between 2 angles in Javascript using p5.js

1 Answers1