scottaiton.github.io/index.html at master · scottaiton/scottaiton.github.io · GitHub

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<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <title>Hello WebGL</title>
    <meta name="generator" content="BBEdit 10.5" />

    <!-- load matrix manipulation helper methods -->
    <script type="text/javascript" src="glMatrix_util.js"></script>
    <script type="text/javascript" src="webgl-utils.js"></script>
    <script type="text/javascript" src="ReadClawAscii.js"></script>
    <script type="text/javascript" src="MeshGeometry.js"></script>
    <script type="text/javascript" src="Mesh.js"></script>

    <!-- define our shaders -->
    <script id="shader-fs" type="x-shader/x-fragment">
      precision mediump float;

      uniform vec3 uColormap[256];
      uniform float uColormapSize;
      uniform float uColormapLength;
      uniform float uColorMin;
      uniform float uColorMax;

      varying float vZ;

      uniform sampler2D uSampler;

      void main(void) {
          if(vZ<uColorMin){
            gl_FragColor = texture2D(uSampler, vec2(0.0, 0.5));
          }else if(vZ>uColorMax){
            gl_FragColor = texture2D(uSampler, vec2((0.5+uColormapSize-1.0)/uColormapLength, 0.5));
          }else{
            float float_index = (vZ-uColorMin)*(uColormapSize-1.0)/(uColorMax-uColorMin);
            float index = floor(float_index);
            float t = float_index-index;
            vec4 low_color = texture2D(uSampler, vec2((0.5+index)/uColormapLength, 0.5));
            vec4 high_color = texture2D(uSampler, vec2((0.5+index+1.0)/uColormapLength, 0.5));
            gl_FragColor = mix(low_color, high_color, t);
          }
      }
    </script>

    <script id="shader-vs" type="x-shader/x-vertex">
      attribute vec3 aVertexPosition;

      uniform mat4 uMVMatrix;
      uniform mat4 uRotMatrix;
      uniform mat4 uPMatrix;

      varying float vZ;

      void main(void) {
          vZ = aVertexPosition.z;
          gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
      }
    </script>

    <script>
         <!-- define Javascript functions for drawing WebGL items -->

        var gl;
        var patches = new Array();
        var geometry;
        var mesh;

        function initWebGLContext(aname) {
          gl = null;
          var canvas = document.getElementById(aname);
          try {
            // Try to grab the standard context. If it fails, fallback to experimental.
            gl = canvas.getContext("webgl") || canvas.getContext("experimental-webgl");
          }
          catch(e) {}

          // If we don't have a GL context, give up now
          if (!gl) {
            alert("Unable to initialize WebGL. Your browser may not support it.");
            gl = null;
          }
          gl.viewportWidth = canvas.width;
          gl.viewportHeight = canvas.height;
          return gl;
        }
        // define the function to initial WebGL and Setup Geometry Objects
        function initGLScene()
        {
            // Initialize the WebGL Context - the gl engine for drawing things.
            var gl = initWebGLContext("hellowebgl"); // The id of the Canvas Element
                if (!gl) // if fails simply return
             {
                  return;
             }
             // succeeded in initializing WebGL system
             gl.getExtension('OES_standard_derivatives');
             return gl;
        }


           function getShader(gl, id) {
                var shaderScript = document.getElementById(id);
                if (!shaderScript) {
                    return null;
                }

                var str = "";
                var k = shaderScript.firstChild;
                while (k) {
                    if (k.nodeType == 3) {
                        str += k.textContent;
                    }
                    k = k.nextSibling;
                }

                var shader;
                if (shaderScript.type == "x-shader/x-fragment") {
                    shader = gl.createShader(gl.FRAGMENT_SHADER);
                } else if (shaderScript.type == "x-shader/x-vertex") {
                    shader = gl.createShader(gl.VERTEX_SHADER);
                } else {
                    return null;
                }

                gl.shaderSource(shader, str);
                gl.compileShader(shader);

                if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
                    alert(gl.getShaderInfoLog(shader));
                    return null;
                }

                return shader;
            }


            var shaderProgram;
            var boxShaderProgram;

            function initShaders() {
                var fragmentShader = getShader(gl, "shader-fs");
                var vertexShader = getShader(gl, "shader-vs");
                // main shader
                shaderProgram = gl.createProgram();
                gl.attachShader(shaderProgram, vertexShader);
                gl.attachShader(shaderProgram, fragmentShader);
                gl.linkProgram(shaderProgram);

                if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
                    alert("Could not initialise shaders");
                }
                gl.useProgram(shaderProgram);

                //main shader
                shaderProgram.vertexPositionAttribute = gl.getAttribLocation(shaderProgram, "aVertexPosition");
                gl.enableVertexAttribArray(shaderProgram.vertexPositionAttribute);

                shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
                shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
                shaderProgram.rotMatrixUniform = gl.getUniformLocation(shaderProgram, "uRotMatrix");
                shaderProgram.colormapUniform = gl.getUniformLocation(shaderProgram, "uColormap");
                shaderProgram.colormapSizeUniform = gl.getUniformLocation(shaderProgram, "uColormapSize");
                shaderProgram.colormapLengthUniform = gl.getUniformLocation(shaderProgram, "uColormapLength");
                shaderProgram.colorMinUniform = gl.getUniformLocation(shaderProgram, "uColorMin");
                shaderProgram.colorMaxUniform = gl.getUniformLocation(shaderProgram, "uColorMax");
                shaderProgram.samplerUniform = gl.getUniformLocation(shaderProgram, "uSampler");
            }

      var jet = [
          0.000000,0.000000,0.562500,
          0.000000,0.000000,0.625000,
          0.000000,0.000000,0.687500,
          0.000000,0.000000,0.750000,
          0.000000,0.000000,0.812500,
          0.000000,0.000000,0.875000,
          0.000000,0.000000,0.937500,
          0.000000,0.000000,1.000000,
          0.000000,0.062500,1.000000,
          0.000000,0.125000,1.000000,
          0.000000,0.187500,1.000000,
          0.000000,0.250000,1.000000,
          0.000000,0.312500,1.000000,
          0.000000,0.375000,1.000000,
          0.000000,0.437500,1.000000,
          0.000000,0.500000,1.000000,
          0.000000,0.562500,1.000000,
          0.000000,0.625000,1.000000,
          0.000000,0.687500,1.000000,
          0.000000,0.750000,1.000000,
          0.000000,0.812500,1.000000,
          0.000000,0.875000,1.000000,
          0.000000,0.937500,1.000000,
          0.000000,1.000000,1.000000,
          0.062500,1.000000,0.937500,
          0.125000,1.000000,0.875000,
          0.187500,1.000000,0.812500,
          0.250000,1.000000,0.750000,
          0.312500,1.000000,0.687500,
          0.375000,1.000000,0.625000,
          0.437500,1.000000,0.562500,
          0.500000,1.000000,0.500000,
          0.562500,1.000000,0.437500,
          0.625000,1.000000,0.375000,
          0.687500,1.000000,0.312500,
          0.750000,1.000000,0.250000,
          0.812500,1.000000,0.187500,
          0.875000,1.000000,0.125000,
          0.937500,1.000000,0.062500,
          1.000000,1.000000,0.000000,
          1.000000,0.937500,0.000000,
          1.000000,0.875000,0.000000,
          1.000000,0.812500,0.000000,
          1.000000,0.750000,0.000000,
          1.000000,0.687500,0.000000,
          1.000000,0.625000,0.000000,
          1.000000,0.562500,0.000000,
          1.000000,0.500000,0.000000,
          1.000000,0.437500,0.000000,
          1.000000,0.375000,0.000000,
          1.000000,0.312500,0.000000,
          1.000000,0.250000,0.000000,
          1.000000,0.187500,0.000000,
          1.000000,0.125000,0.000000,
          1.000000,0.062500,0.000000,
          1.000000,0.000000,0.000000,
          0.937500,0.000000,0.000000,
          0.875000,0.000000,0.000000,
          0.812500,0.000000,0.000000,
          0.750000,0.000000,0.000000,
          0.687500,0.000000,0.000000,
          0.625000,0.000000,0.000000,
          0.562500,0.000000,0.000000,
          0.500000,0.000000,0.000000];


        // create our basic model and view matrix
        var mvMatrix = mat4.create();
        var rotMatrix = mat4.create();
        var mvMatrixStack = [];
        // create our projection matrix for projecting from 3D to 2D.
        var pMatrix = mat4.create();
        //other unifomrs
        var dirLight = [0.0, -1.0, 0.0];
        var shaderType = 0;
        var textureType = 0;
        var ni=32;
        var nj=16;
        var ambientWeight=0.5;
        var diffuseWeight=0.5;
        var phongWeight=0.5;
        var useBumpMap=false;
        var nShiny=10;
        var colormap = [0.0,1.0,0.0,
                        0.0,0.0,1.0];
        var colorMin=0.0;
        var colorMax=1.0;
        var colormapTexture;

         function mvPushMatrix() {
                var copy = mat4.create();
                mat4.set(mvMatrix, copy);
                mvMatrixStack.push(copy);
            }

            function mvPopMatrix() {
                if (mvMatrixStack.length == 0) {
                    throw "Invalid popMatrix!";
                }
                mvMatrix = mvMatrixStack.pop();
            }

        function setMatrixUniforms()
        {
                gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, pMatrix);
                gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix);
                gl.uniformMatrix4fv(shaderProgram.rotMatrixUniform, false, rotMatrix);
                gl.uniform1f(shaderProgram.colormapSizeUniform, colormapTexture.length);
                gl.uniform1f(shaderProgram.colormapLengthUniform, colormapTexture.data.length/4);
                gl.uniform1f(shaderProgram.colorMaxUniform, colorMax);
                gl.uniform1f(shaderProgram.colorMinUniform, colorMin);
        }


        // create and initialize our geometry objects
        var gridVertexPositionBuffer;
        var gridVertexTextureCoordBuffer;
        var gridVertexIndexBuffer;
        var gridVertexNormalBuffer;
        var radius = 1.27374; //1000 km

        function reloadGeometry(in_patches)
        {
            patches = in_patches;
            mesh = new Mesh(patches);
            geometry = new MeshGeometry(gl,mesh);
            colorMax = mesh.max_value;
            colorMin = mesh.min_value;
        }


        // Initialize our texture data and prepare it for rendering
        function initTextures()
        {
          colormapTexture = gl.createTexture();
          updateColormap(colormap);
        }

        function updateColormap(colormap){
            colormapTexture.data = new Uint8Array(4*Math.pow(2,Math.ceil(Math.log2(colormap.length/3))));
            colormapTexture.length = colormap.length/3;
            for(var i=0;i<colormap.length/3;i++){
                colormapTexture.data[4*i+0] = Math.round(255*colormap[3*i+0]);
                colormapTexture.data[4*i+1] = Math.round(255*colormap[3*i+1]);
                colormapTexture.data[4*i+2] = Math.round(255*colormap[3*i+2]);
                colormapTexture.data[4*i+3] = 255;
            }
            gl.bindTexture(gl.TEXTURE_2D, colormapTexture);
            gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
            gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, colormapTexture.data.length/4, 1, 0,
                          gl.RGBA, gl.UNSIGNED_BYTE, colormapTexture.data);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
            gl.bindTexture(gl.TEXTURE_2D, null);
         }

        function handleLoadedTexture(texture)
        {
            gl.bindTexture(gl.TEXTURE_2D, texture);
            gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
            gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, texture.image);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
            gl.bindTexture(gl.TEXTURE_2D, null);
        }


        var xRot = 0;
        var yRot = 0;
        var zRot = 0;
        var scroll = 0;
        var enableBox = false;
        function initListeners(){
          var canvas = document.getElementById("hellowebgl");
          var xPrev, yPrev;
          var rotating = false;
          var panning = false;
          canvas.addEventListener("mousedown",function(e){
              xPrev = e.pageX;
              yPrev = e.pageY;
              rotating = e.button==0;
              panning = e.button==2;
          },false);
          canvas.addEventListener("mouseup",function(e){
              rotating=false;
              panning=false;
          },false);
          canvas.addEventListener("mouseleave",function(e){
              rotating=false;
              panning=false;
          },false);
          canvas.addEventListener("mousemove",function(e){
              if(rotating){
                  var xDelta = e.pageX-xPrev;
                  var yDelta = e.pageY-yPrev;
                  xPrev = e.pageX;
                  yPrev = e.pageY;
                  xRot += yDelta*360/canvas.height;
                  yRot += xDelta*360/canvas.width;
                  //limit rotation
                  if(xRot>90){
                      xRot = 90;
                  }else if(xRot<-90){
                      xRot = -90;
                  }
              }
              if(panning){

              }
          },false);

          canvas.addEventListener("wheel",function(e){
              scroll += e.deltaY/1000;
          },false)

          document.getElementById('file').addEventListener('change',function(evt){
              var file = evt.target.files[0];
              ReadClawAscii.readFile(file,reloadGeometry);
          },false)
        }

        //Initialize everything for starting up a simple webGL application
        function startHelloWebGL()
        {
           // attach 'Handler' functions to handle events generated by the canvas.
           // for when the browser is resized or closed.

           // first initialize webgl components
           var gl = initGLScene();

           // now build basic geometry objects.
           initShaders();
           reloadGeometry(patches);
           initTextures(colormap);

           gl.clearColor(0.4,0.4,0.4,1.0);
           gl.enable(gl.DEPTH_TEST);
           // Draw the Scene
           Frames();
           // If doing an animation need to add code to rotate our geometry

           initListeners();
        }

        // This function draws a basic webGL scene
        // first it clears the framebuffer.
        // then we define our View positions for our camera using WebGL matrices.
        // OpenGL has convenience methods for this such as glPerspective().
        // finally we call the gl draw methods to draw our defined geometry objects.

        function drawScene() {
            gl.viewport(0, 0, gl.viewportWidth, gl.viewportHeight);
            gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

            if(!geometry.empty) {
                mat4.perspective(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0, pMatrix);

                mat4.identity(mvMatrix);

                mat4.translate(mvMatrix, [0.0, 0.0, -5.0]);

                var scale = 1.0*Math.pow(10,-scroll);
                mat4.scale(mvMatrix, [scale,scale,scale]);

                mat4.identity(rotMatrix);
                mat4.rotate(rotMatrix, xRot/180.0*3.1415, [1, 0, 0]);

                mat4.rotate(rotMatrix, yRot/180.0*3.1415, [0, 1, 0]);

                //rotate to graphics coords
                mat4.rotate(rotMatrix, -90/180.0*3.1415, [1, 0, 0]);

                mat4.multiply(mvMatrix,rotMatrix,mvMatrix);
                //move to center
                mat4.translate(mvMatrix, [-(mesh.tree.xmin+mesh.tree.xmax)/2.0, -(mesh.tree.ymin+mesh.tree.ymax)/2.0, 0.0]);


                gl.useProgram(shaderProgram);

                gl.bindBuffer(gl.ARRAY_BUFFER, geometry.positionBuffer);
                gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, geometry.positionBuffer.itemSize, gl.FLOAT, false, 0, 0);

                gl.activeTexture(gl.TEXTURE0);
                gl.bindTexture(gl.TEXTURE_2D, colormapTexture);
                gl.uniform1i(shaderProgram.samplerUniform, 0);

                gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, geometry.vertexIndexBuffer);
                setMatrixUniforms();
                var ext = gl.getExtension('OES_element_index_uint');

                gl.drawElements(gl.TRIANGLES, geometry.vertexIndexBuffer.numItems, gl.UNSIGNED_INT, 0);
            }
        }


            var lastTime = 0;
            var sun_pos = 0;

            function animate() {
                var timeNow = new Date().getTime();
                if (lastTime != 0) {
                    var elapsed = timeNow - lastTime;
                    //xRot=50;

                    var rate = 8; //rpm
                    sun_pos+=360*rate*elapsed/(60*1000);
                    sun_pos=sun_pos%360;

                    var sun_rads = sun_pos/180.0*3.1415;
                    dirLight = [-Math.sin(sun_rads),0,-Math.cos(sun_rads)];
                }
                lastTime = timeNow;
            }


            function Frames() {
                requestAnimFrame(Frames);
                drawScene();
                animate();
            }
    </script>
  </head>

  <!-- declare the "body" of the HTML document-->
  <!-- the onload attribute specifies a javascript function to execute when the body tag is loaded into the browser -->

  <body onload="startHelloWebGL()">
    <h1>Surface Plot!</h1>

    <!-- embed the HTML5 Canvas Drawing object on the page.-->
    <!-- Name the canvas 'hellowebgl' for the javascript code. -->
    <canvas id="hellowebgl" width="640" height="480">
      If you're seeing this your web browser doesn't support the &lt;canvas>&gt;
      element. Ouch!
    </canvas>
    <br />
    <input type="file" id="file" />
  </body>
</html>