// The Nature of Code

// The Coding Train / Daniel Shiffman / Dusk

// https://youtu.be/pUhv2CA0omA

// https://thecodingtrain.com/learning/nature-of-code/4.4-image-textures.html

​

// Texture Maker: https://editor.p5js.org/codingtrain/sketches/NS4rB1Yx-

// Image Texture: https://editor.p5js.org/codingtrain/sketches/TTVoNt58T

// Shader (WEBGL): https://editor.p5js.org/codingtrain/sketches/EXZmcc4m_

​

let emitter;

​

let sh;

const numParticles = 153; // must also be changed in shader

let particleData = [];

​

function preload() {

  sh = loadShader('shader.vert', 'shader.frag');

}

​

function setup() {

  createCanvas(400, 400, WEBGL);

  emitter = new Emitter(200, 375);

  for (let i = 0; i < numParticles; ++i) {

    particleData.push(createVector(0, 0, 0));

  }

}

​

function draw() {

  let force = createVector(0, -0.1);

  emitter.applyForce(force);

​

  let dir = map(mouseX, width, 0, -0.1, 0.1);

  let wind = createVector(dir, 0);

  emitter.applyForce(wind);

​

  emitter.emit(3);

  emitter.show(particleData);

  emitter.update();

​

  translate(-width / 2, -height / 2);

​

  shader(sh);

​

  arrayUniform(sh, 'particle', particleData);

​

  rect(0, 0, width, height);

}

​

function arrayUniform(shader_, uniformName, vectorArray) {

  for (let i = 0; i < vectorArray.length; ++i) {

    shader_.setUniform(uniformName + i, [

      vectorArray[i].x,

      vectorArray[i].y,

      vectorArray[i].z,

    ]);

  }

}

​