ShaderPlayground/main.html at main · QuackingBob/ShaderPlayground · GitHub

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<!DOCTYPE html>
<html>

<head>
  <title>Shaders</title>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/gl-matrix/2.8.1/gl-matrix-min.js"></script>
  <script src="vertexShader.glsl"></script>
  <script src="fragmentShader.glsl"></script>
</head>

<body>
  <h3 id="fps_counter">FPS: </h3>
  <canvas id="webgl-canvas"></canvas>
  <h3>Logs</h3>
  <p id="log"></p>
  <script>
    async function main() {
      var vert;
      var frag;

      const response1 = await fetch('vertexShader.glsl');
      vert = await response1.text();
      // console.log(vert);

      const response2 = await fetch('fragmentShader.glsl');
      frag = await response2.text();
      // console.log(frag);

      console.log("vert: " + vert);
      console.log("frag: " + frag);

      // fetch ('vertexShader.glsl')
      //   .then(response => response.text())
      //   .then(vertexShaderSource => {
      //     vert = vertexShaderSource;
      //     console.log(vertexShaderSource);
      //   });

      // fetch ('fragmentShader.glsl')
      //   .then(response => response.text())
      //   .then(fragmentShaderSource => {
      //     frag = fragmentShaderSource;
      //     console.log(fragmentShaderSource);
      //   });

      var canvas = document.getElementById("webgl-canvas");
      canvas.height = 600;
      canvas.width = 700;
      var gl = document.getElementById("webgl-canvas").getContext('webgl');
      var vertexShader = createShader(gl, gl.VERTEX_SHADER, vert);
      var fragmentShader = createShader(gl, gl.FRAGMENT_SHADER, frag);
      var program = createProgram(gl, vertexShader, fragmentShader);
      const timeLocation = gl.getUniformLocation(program, "time");
      var positionAttributeLocation = gl.getAttribLocation(program, "a_position");
      var positionBuffer = gl.createBuffer();
      gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
      var positions = [
        -1, -1,
        -1, 1,
        1, 1,
        1, 1,
        1, -1,
        -1, -1,
      ];
      gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions), gl.STATIC_DRAW);

      var fps_counter = document.getElementById("fps_counter");
      var elapsed_time = 0;

      function render(time) {
        gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);
        gl.clearColor(0, 0, 0, 0);
        gl.clear(gl.COLOR_BUFFER_BIT);
        gl.useProgram(program);
        gl.enableVertexAttribArray(positionAttributeLocation);
        gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
        // // Tell the attribute how to get data out of positionBuffer (ARRAY_BUFFER)
        var size = 2;          // 2 components per iteration
        var type = gl.FLOAT;   // the data is 32bit floats
        var normalize = false; // don't normalize the data
        var stride = 0;        // 0 = move forward size * sizeof(type) each iteration to get the next position
        var offset = 0;        // start at the beginning of the buffer
        gl.vertexAttribPointer(
          positionAttributeLocation, size, type, normalize, stride, offset)

        gl.uniform1f(timeLocation, time * 0.001);
        var primitiveType = gl.TRIANGLES;
        var offset = 0;
        var count = 6;
        gl.drawArrays(primitiveType, offset, count);

        var fps = 1000 / (performance.now() - time);
        elapsed_time += performance.now() - time;
        if (elapsed_time > 200) {
          fps_counter.innerHTML = "FPS: " + Math.round(fps);
          elapsed_time = 0;
        }

        requestAnimationFrame(render);
      }

      requestAnimationFrame(render);
    }

    main();

    function createProgram(gl, vs, fs) {
      const p = gl.createProgram();
      gl.attachShader(p, vs);
      gl.attachShader(p, fs);
      gl.linkProgram(p);
      return p;
    }

    function createShader(gl, type, src) {
      const s = gl.createShader(type);
      gl.shaderSource(s, src);
      gl.compileShader(s);
      if (!gl.getShaderParameter(s, gl.COMPILE_STATUS)) {
        console.error('An error occurred compiling the shaders: ' + gl.getShaderInfoLog(s));
        text = document.getElementById("log")
        text.innerHTML += gl.getShaderInfoLog(s) + "\n\n";
        gl.deleteShader(s);
        return null;
      }
      else {
        console.log("successfully loaded shader " + type);
        text = document.getElementById("log")
        text.innerHTML += "successfully loaded shader " + type + "\n\n";
      }
      return s;
    }
  </script>

  <input type="file" id="fileInput" onchange="loadImage()" />
  <br />
  <canvas id="canvas"></canvas>
  <script>
    async function loadImage() {
      const fileInput = document.getElementById("fileInput");
      const canvas = document.getElementById("canvas");
      const ctx = canvas.getContext("2d");
      const file = fileInput.files[0];
      const reader = new FileReader();
      reader.onload = function (e) {
        const img = new Image();
        img.onload = function () {
          canvas.width = 512;
          canvas.height = (canvas.width / img.width) * img.height;
          ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
        };
        img.src = e.target.result;
        console.log("loaded image \"" + img.src + "\"");
      };
      reader.readAsDataURL(file);
    }
  </script>
</body>

</html>