Project5-WebGL/vert_wave_custom.html at master · XJMa/Project5-WebGL · GitHub

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<html>

<head>
<title>Vertex Wave</title>
<meta charset ="utf-8">
<meta http-equiv="X-UA-Compatible" content="chrome=1">  <!-- Use Chrome Frame in IE -->
</head>

<body>
<div id="message" style="position:absolute;top:100px"></div> <!-- Pixel offset to avoid FPS counter -->
<canvas id="canvas" style="border: none;" width="1024" height="768" tabindex="1"></canvas>
<script src ="js/lib/gl-matrix.js" type ="text/javascript"></script>
<script src ="js/webGLUtility.js" type ="text/javascript"></script>
<script src="js/lib/dat.gui.min.js" type="text/javascript"></script>

<script id="vs" type="x-shader/x-vertex">
    attribute vec2 position;

    uniform mat4 u_modelViewPerspective;

    uniform float u_time;
    uniform vec3 u_mincolor;
    uniform vec3 u_maxcolor;

    varying vec3 fs_color; //input
    void main(void)
    {
      // NOTE : according to the WebGL standard, 0.0f is not accepted
          float dis = sqrt( (position.x-0.5)*(position.x-0.5) + (position.y-0.5)*(position.y-0.5) );
          float s_contrib = sin(5.0*dis*3.14159 + u_time);
          //float t_contrib = cos(position.y*2.0*3.14159 + u_time);
          float height = s_contrib / (1.0 + 5.0 * dis);;
          float alpha = (height+1.0)/2.0;
          fs_color = mix(u_mincolor/255.0, u_maxcolor/255.0,alpha );
      // NOTE : gl_Position is always a vec4
		  gl_Position = u_modelViewPerspective * vec4(vec3(position, height), 1.0);
    }
</script>

<script id="fs" type="x-shader/x-fragment">
    precision mediump float;
    uniform vec4 u_color;
    varying vec3 fs_color;  //output
    void main(void)
    {
      // NOTE : gl_FragColor is always a vec4
		  gl_FragColor = vec4(fs_color,1.0);
    }
</script>

<script>
  // Globals
  var positionLocation = 0;
  var heightLocation = 1;
  var u_modelViewPerspectiveLocation;
  var u_color;

  var heights;
  var numberOfIndices;

  var eye = [2.0, 1.0, 3.0];
  var center = [0.0, 0.0, 0.0];
  var up = [0.0, 0.0, 1.0];
  var NUM_WIDTH_PTS = 32;
  var NUM_HEIGHT_PTS = 32;
  var message;
  var canvas;
  var context;
  var persp = mat4.create();
  var view = mat4.create();
  //Added
  var time = 0.0;
  var u_timeLocation;
  var u_mincolorLocation;
  var u_maxcolorLocation;
  var Colors = {
      mincolor : [100, 100, 255],
      maxcolor : [255, 100, 100]
  };
  // Function called when the window is loaded
  window.onload = function () {
      // Add GUI component
      var gui = new dat.GUI();
      gui.addColor(Colors, 'mincolor');
      gui.addColor(Colors, 'maxcolor');
      init();
      animate();
  };
  function init() {
    message = document.getElementById("message");
    canvas = document.getElementById("canvas");
    context = createWebGLContext(canvas, message);
    if (!context) {
      return;
    }
    // SET UP WEBGL CONTEXT
    context.viewport(0, 0, canvas.width, canvas.height);
    context.clearColor(1.0, 1.0, 1.0, 1.0);
    context.enable(context.DEPTH_TEST);
    mat4.perspective(45.0, 0.5, 0.1, 100.0, persp);
    mat4.lookAt(eye, center, up, view);

    initializeShader();
    initializeGrid();
  }
  function animate(){
    // Update
    var model = mat4.create();
    mat4.identity(model);
    mat4.translate(model, [-0.5, -0.5, 0.0]);
    var mv = mat4.create();
    mat4.multiply(view, model, mv);
    var mvp = mat4.create();
    mat4.multiply(persp, mv, mvp);
    //Added
    time = time + 0.03;
    if (time == 3.14159 * 100.0)
        time = 0.0;
    // Render
    context.clear(context.COLOR_BUFFER_BIT | context.DEPTH_BUFFER_BIT);
    context.uniformMatrix4fv(u_modelViewPerspectiveLocation, false, mvp);
    context.drawElements(context.LINES, numberOfIndices, context.UNSIGNED_SHORT, 0);
    //Added
    context.uniform1f(u_timeLocation, time);

    context.uniform3f(u_mincolorLocation, Colors.mincolor[0], Colors.mincolor[1], Colors.mincolor[2]);
    context.uniform3f(u_maxcolorLocation, Colors.maxcolor[0], Colors.maxcolor[1], Colors.maxcolor[2]);
    window.requestAnimFrame(animate);
  }
  function initializeShader() {
    var program;
    var vs = getShaderSource(document.getElementById("vs"));
    var fs = getShaderSource(document.getElementById("fs"));
		var program = createProgram(context, vs, fs, message);
		context.bindAttribLocation(program, positionLocation, "position");
		u_modelViewPerspectiveLocation = context.getUniformLocation(program,"u_modelViewPerspective");
    u_colorLocation = context.getUniformLocation(program, "u_color");
    //Added
    u_timeLocation = context.getUniformLocation(program, "u_time");
    u_mincolorLocation = context.getUniformLocation(program, "u_mincolor");
    u_maxcolorLocation = context.getUniformLocation(program, "u_maxcolor");
    context.useProgram(program);
  }
  function initializeGrid() {
    function uploadMesh(positions, heights, indices) {
      // Positions
      var positionsName = context.createBuffer();
      context.bindBuffer(context.ARRAY_BUFFER, positionsName);
      context.bufferData(context.ARRAY_BUFFER, positions, context.STREAM_DRAW);
      context.vertexAttribPointer(positionLocation, 2, context.FLOAT, false, 0, 0);
      context.enableVertexAttribArray(positionLocation);
      if (heights){
        // Heights
        var heightsName = context.createBuffer();
        context.bindBuffer(context.ARRAY_BUFFER, heightsName);
        context.bufferData(context.ARRAY_BUFFER, heights.length *
                            heights.BYTES_PER_ELEMENT, context.STATIC_DRAW);
        context.vertexAttribPointer(heightLocation, 1, context.FLOAT, false, 0, 0);
        context.enableVertexAttribArray(heightLocation);
      }
      // Indices
      var indicesName = context.createBuffer();
      context.bindBuffer(context.ELEMENT_ARRAY_BUFFER, indicesName);
      context.bufferData(context.ELEMENT_ARRAY_BUFFER, indices, context.STATIC_DRAW);
    }
    var WIDTH_DIVISIONS = NUM_WIDTH_PTS - 1;
    var HEIGHT_DIVISIONS = NUM_HEIGHT_PTS - 1;
    var numberOfPositions = NUM_WIDTH_PTS * NUM_HEIGHT_PTS;
    var positions = new Float32Array(2 * numberOfPositions);
    var indices = new Uint16Array(2 * ((NUM_HEIGHT_PTS * (NUM_WIDTH_PTS - 1)) +
                                (NUM_WIDTH_PTS * (NUM_HEIGHT_PTS - 1))));
    var positionsIndex = 0;
    var indicesIndex = 0;
    var length;
    for (var j = 0; j < NUM_WIDTH_PTS; ++j){
      positions[positionsIndex++] = j /(NUM_WIDTH_PTS - 1);
      positions[positionsIndex++] = 0.0;
      if (j>=1){
        length = positionsIndex / 2;
        indices[indicesIndex++] = length - 2;
        indices[indicesIndex++] = length - 1;
      }
    }
    for (var i = 0; i < HEIGHT_DIVISIONS; ++i){
      var v = (i + 1) / (NUM_HEIGHT_PTS - 1);
      positions[positionsIndex++] = 0.0;
      positions[positionsIndex++] = v;
      length = (positionsIndex / 2);
      indices[indicesIndex++] = length - 1;
      indices[indicesIndex++] = length - 1 - NUM_WIDTH_PTS;
      for (var k = 0; k < WIDTH_DIVISIONS; ++k){
        positions[positionsIndex++] = (k + 1) / (NUM_WIDTH_PTS - 1);
        positions[positionsIndex++] = v;
        length = positionsIndex / 2;
        var new_pt = length - 1;
        indices[indicesIndex++] = new_pt - 1;  // Previous side
        indices[indicesIndex++] = new_pt;
        indices[indicesIndex++] = new_pt - NUM_WIDTH_PTS;  // Previous bottom
        indices[indicesIndex++] = new_pt;
      }
    }
    uploadMesh(positions, heights, indices);
    numberOfIndices = indices.length;
}
</script>

</body>

</html>