在p5.js中是否有一种简单的方法可以在不同的shaderoy着色器之间定相？

Question

我正在寻找一种方法，可以在shadertoy.com的多个着色器之间切换我一直在使用有关如何移植shadertoys with p5.js的说明，并已成功地将sublime与它或一个名为glitch.com的网站一起使用]

我的问题是，如何循环显示一个着色器到下一个着色器？这是到目前为止的javascript文件。我知道我需要使用函数draw和一个循环来调用我预加载的两个不同的着色器，但是由于我对编码非常陌生，因此在语法上遇到了一些麻烦。任何帮助，将不胜感激！

let theShader;

function preload(){
  // load the shader
  theShader1 = loadShader('shader1.vert', 'shader1.frag');
  theShader2 = loadShader('shader2.vert', 'shader2.frag');
}

function setup() {
  createCanvas(windowWidth, windowHeight, WEBGL);
  noStroke();
}

function draw() {  
  //sets the active shader with shader1
  shader(theShader1);
  
  theShader1.setUniform("iResolution", [width, height]);
  theShader1.setUniform("iFrame", frameCount);
  theShader1.setUniform("iMouse", [mouseX, map(mouseY, 0, height, height, 0)]);


  // rect gives us some geometry on the screen
  rect(0,0,width, height);
}

function windowResized(){
  resizeCanvas(windowWidth, windowHeight);
}

Answer 1

而不是在平局中使用theShader1。使用theShader，然后根据某物（计时器，计数，用户单击某物）将theShader设置为theShader1或theShader2

    let theShader;
    let oldTime;

    function preload(){
      // load the shader
      theShader1 = loadShader('shader1.vert', 'shader1.frag');
      theShader2 = loadShader('shader2.vert', 'shader2.frag');
      theShader = theShader1;  // start with theShader1
    }

    function setup() {
      createCanvas(windowWidth, windowHeight, WEBGL);
      noStroke();
    }

    function draw() {  
      // switch shaders every second
      let time = performance.now() / 1000 | 0;  // convert to seconds
      if (oldTime !== time) {
        oldTime = time;
        theShader = theShader === theShader1 ? theShader2 : theShader1;
      }

      //sets the active shader
      shader(theShader);

      theShader.setUniform("iResolution", [width, height]);
      theShader.setUniform("iFrame", frameCount);
      theShader.setUniform("iMouse", [mouseX, map(mouseY, 0, height, height, 0)]);

      // rect gives us some geometry on the screen
      rect(0,0,width, height);
    }

    function windowResized(){
      resizeCanvas(windowWidth, windowHeight);
    }

如果您有2个以上的着色器，请将它们放在一个数组中并保留一个索引。例如

    let theShader;
    let oldTime;
    let shaderNdx = 0;

    const shaders = [];

    function preload(){
      // load the shader
      shaders.push(loadShader('shader1.vert', 'shader1.frag'));
      shaders.push(loadShader('shader2.vert', 'shader2.frag'));
      shaders.push(loadShader('shader3.vert', 'shader3.frag'));
      theShader = shaders[0];  // start with the first shader
    }

    function setup() {
      createCanvas(windowWidth, windowHeight, WEBGL);
      noStroke();
    }

    function draw() {  
      // switch shaders every second
      let time = performance.now() / 1000 | 0;  // convert to seconds
      if (oldTime !== time) {
        oldTime = time;
        // increment shader index to the next shader but wrap around 
        // back to 0 at then of the array of shaders
        shaderNdx = (shaderNdx + 1) % shaders.length;
        theShader = shaders[shaderNdx]
      }

      //sets the active shader
      shader(theShader);

      theShader.setUniform("iResolution", [width, height]);
      theShader.setUniform("iFrame", frameCount);
      theShader.setUniform("iMouse", [mouseX, map(mouseY, 0, height, height, 0)]);

      // rect gives us some geometry on the screen
      rect(0,0,width, height);
    }

    function windowResized(){
      resizeCanvas(windowWidth, windowHeight);
    }