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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              
<!DOCTYPE html>
<html>

<script type="text/javascript" src="https://www.cs.unm.edu/~angel/WebGL/7E/Common/webgl-utils.js"></script>
<script type="text/javascript" src="https://www.cs.unm.edu/~angel/WebGL/7E/Common/initShaders.js"></script>
<script type="text/javascript" src="https://www.cs.unm.edu/~angel/WebGL/7E/Common/MV.js"></script>

<script id="vertex-shader" type="x-shader/x-vertex">

attribute  vec4 vPosition;
attribute  vec3 vNormal;
attribute  vec4 vColor;
varying vec4 fColor;

uniform vec4 ambientProduct, diffuseProduct, specularProduct;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
uniform vec4 lightPosition;
uniform float shininess;

void main()
{
    vec3 pos = -(modelViewMatrix * vPosition).xyz;
    vec3 light = lightPosition.xyz;
    vec3 L = normalize( light - pos );

	
    vec3 E = normalize( -pos );
    vec3 H = normalize( L + E );
    
    vec4 NN = vec4(vNormal,0);

    // Transform vertex normal into eye coordinates
    vec3 N = normalize( (modelViewMatrix*NN).xyz);

    // Compute terms in the illumination equation
    //vec4 ambient = ambientProduct;
    vec4 ambient = 0.5*vColor;

    float Kd = max( dot(L, N), 0.0 );
    vec4  diffuse = Kd*diffuseProduct;

    float Ks = pow( max(dot(N, H), 0.0), shininess );
    vec4  specular = Ks * specularProduct;
    
    if( dot(L, N) < 0.0 ) {
	specular = vec4(0.0, 0.0, 0.0, 1.0);
    } 

    gl_Position = projectionMatrix * modelViewMatrix * vPosition;
    fColor = ambient + diffuse +specular;
    
    fColor.a = 1.0;
} 
</script>

<script id="fragment-shader" type="x-shader/x-fragment">
precision mediump float;

uniform int i;

varying vec4 fColor;

void main()
{
    vec4 c[7];
    c[0] = fColor;
    c[1] = vec4(1.0, 0.0, 0.0, 1.0);
    c[2] = vec4(0.0, 1.0, 0.0, 1.0);
    c[3] = vec4(0.0, 0.0, 1.0, 1.0);
    c[4] = vec4(1.0, 1.0, 0.0, 1.0);
    c[5] = vec4(0.0, 1.0, 1.0, 1.0);
    c[6] = vec4(1.0, 0.0, 1.0, 1.0);
    

    if(i==0) gl_FragColor = c[0];
    else if(i==1) gl_FragColor = c[1];
    else if(i==2) gl_FragColor = c[2];
    else if(i==3) gl_FragColor = c[3];
    else if(i==4) gl_FragColor = c[4];
    else if(i==5) gl_FragColor = c[5];
    else if(i==6) gl_FragColor = c[6];
}
</script>


<body>
<div>
<canvas id="gl-canvas" width="512" height="512">
Oops ... your browser doesn't support the HTML5 canvas element
</canvas>
</div>
<div>
<button id = "ButtonX">Rotate X</button>
<button id = "ButtonY">Rotate Y</button>
<button id = "ButtonZ">Rotate Z</button>
<button id = "ButtonT">Toggle Rotation</button>
</div>
<div id = "test">
face
</div>
</body>
</html>

            
          
!
            
              var elt;

var canvas;
var gl;

var program;

var NumVertices  = 36;

var pointsArray = [];
var normalsArray = [];
var colorsArray = [];

var framebuffer;

var flag = true;

var color = new Uint8Array(4);

var vertices = [
        vec4( -0.5, -0.5,  0.5, 1.0 ),
        vec4( -0.5,  0.5,  0.5, 1.0 ),
        vec4( 0.5,  0.5,  0.5, 1.0 ),
        vec4( 0.5, -0.5,  0.5, 1.0 ),
        vec4( -0.5, -0.5, -0.5, 1.0 ),
        vec4( -0.5,  0.5, -0.5, 1.0 ),
        vec4( 0.5,  0.5, -0.5, 1.0 ),
        vec4( 0.5, -0.5, -0.5, 1.0 ),
    ];
    
var vertexColors = [
        vec4( 0.0, 0.0, 0.0, 1.0 ),  // black
        vec4( 1.0, 0.0, 0.0, 1.0 ),  // red
        vec4( 1.0, 1.0, 0.0, 1.0 ),  // yellow
        vec4( 0.0, 1.0, 0.0, 1.0 ),  // green
        vec4( 0.0, 0.0, 1.0, 1.0 ),  // blue
        vec4( 1.0, 0.0, 1.0, 1.0 ),  // magenta
        vec4( 0.0, 1.0, 1.0, 1.0 ),  // cyan
        vec4( 1.0, 1.0, 1.0, 1.0 ),   // white
    ];


var lightPosition = vec4(1.0, 1.0, 1.0, 0.0 );
var lightAmbient = vec4(0.2, 0.2, 0.2, 1.0 );
var lightDiffuse = vec4( 1.0, 1.0, 1.0, 1.0 );
var lightSpecular = vec4( 1.0, 1.0, 1.0, 1.0 );

//var materialAmbient = vec4( 1.0, 0.0, 1.0, 1.0 );
var materialAmbient = vec4( 1.0, 1.0, 1.0, 1.0 );
//var materialDiffuse = vec4( 1.0, 0.8, 0.0, 1.0);
var materialDiffuse = vec4( 0.5, 0.5, 0.5, 1.0);
var materialSpecular = vec4( 1.0, 0.8, 0.0, 1.0 );
var materialShininess = 10.0;

var ctm;
var ambientColor, diffuseColor, specularColor;
var modelView, projection;
var viewerPos;
var program;

var xAxis = 0;
var yAxis = 1;
var zAxis = 2;
var axis = xAxis;

var theta = [45.0, 45.0, 45.0];

var thetaLoc;

var Index = 0;


function quad(a, b, c, d) {

     var t1 = subtract(vertices[b], vertices[a]);
     var t2 = subtract(vertices[c], vertices[b]);
     var normal = cross(t1, t2);
     var normal = vec3(normal);
     normal = normalize(normal);

     pointsArray.push(vertices[a]); 
     normalsArray.push(normal); 
     colorsArray.push(vertexColors[a]);
     pointsArray.push(vertices[b]); 
     normalsArray.push(normal); 
     colorsArray.push(vertexColors[a]);
     pointsArray.push(vertices[c]); 
     normalsArray.push(normal);  
     colorsArray.push(vertexColors[a]); 
     pointsArray.push(vertices[a]);  
     normalsArray.push(normal); 
     colorsArray.push(vertexColors[a]);
     pointsArray.push(vertices[c]); 
     normalsArray.push(normal); 
     colorsArray.push(vertexColors[a]);
     pointsArray.push(vertices[d]); 
     normalsArray.push(normal);  
     colorsArray.push(vertexColors[a]);  
}


function colorCube()
{
    quad( 1, 0, 3, 2 );
    quad( 2, 3, 7, 6 );
    quad( 3, 0, 4, 7 );
    quad( 6, 5, 1, 2 );
    quad( 4, 5, 6, 7 );
    quad( 5, 4, 0, 1 );
}


window.onload = function init() {
    canvas = document.getElementById( "gl-canvas" );
    
    var ctx = canvas.getContext("experimental-webgl", {preserveDrawingBuffer: true});
    
    gl = WebGLUtils.setupWebGL( canvas );
    if ( !gl ) { alert( "WebGL isn't available" ); }
    
  
    // Element to show color name
    elt = document.getElementById("test");


    gl.viewport( 0, 0, canvas.width, canvas.height );
    gl.clearColor( 0.5, 0.5, 0.5, 1.0 );
    
    gl.enable(gl.CULL_FACE);
    
    var texture = gl.createTexture();
    gl.bindTexture( gl.TEXTURE_2D, texture );
    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 512, 512, 0, 
       gl.RGBA, gl.UNSIGNED_BYTE, null);
    gl.generateMipmap(gl.TEXTURE_2D);

// Allocate a frame buffer object

   framebuffer = gl.createFramebuffer();
   gl.bindFramebuffer( gl.FRAMEBUFFER, framebuffer);


// Attach color buffer

   gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);

// check for completeness

   //var status = gl.checkFramebufferStatus(gl.FRAMEBUFFER);
   //if(status != gl.FRAMEBUFFER_COMPLETE) alert('Frame Buffer Not Complete');

gl.bindFramebuffer(gl.FRAMEBUFFER, null);

    //
    //  Load shaders and initialize attribute buffers
    //
    program = initShaders( gl, "vertex-shader", "fragment-shader" );
    gl.useProgram( program );
    
    colorCube();
    
    var cBuffer = gl.createBuffer();
    gl.bindBuffer( gl.ARRAY_BUFFER, cBuffer );
    gl.bufferData( gl.ARRAY_BUFFER, flatten(colorsArray), gl.STATIC_DRAW );
    
    var vColor = gl.getAttribLocation( program, "vColor" );
    gl.vertexAttribPointer( vColor, 4, gl.FLOAT, false, 0, 0 );
    gl.enableVertexAttribArray( vColor );


    var nBuffer = gl.createBuffer();
    gl.bindBuffer( gl.ARRAY_BUFFER, nBuffer );
    gl.bufferData( gl.ARRAY_BUFFER, flatten(normalsArray), gl.STATIC_DRAW );
    
    var vNormal = gl.getAttribLocation( program, "vNormal" );
    gl.vertexAttribPointer( vNormal, 3, gl.FLOAT, false, 0, 0 );
    gl.enableVertexAttribArray( vNormal );

    var vBuffer = gl.createBuffer();
    gl.bindBuffer( gl.ARRAY_BUFFER, vBuffer );
    gl.bufferData( gl.ARRAY_BUFFER, flatten(pointsArray), gl.STATIC_DRAW );
    
    var vPosition = gl.getAttribLocation(program, "vPosition");
    gl.vertexAttribPointer(vPosition, 4, gl.FLOAT, false, 0, 0);
    gl.enableVertexAttribArray(vPosition);
    
    viewerPos = vec3(0.0, 0.0, -20.0 );

    projection = ortho(-1, 1, -1, 1, -100, 100);
    
    ambientProduct = mult(lightAmbient, materialAmbient);
    diffuseProduct = mult(lightDiffuse, materialDiffuse);
    specularProduct = mult(lightSpecular, materialSpecular); 
    
    document.getElementById("ButtonX").onclick = function(){axis = xAxis;};
    document.getElementById("ButtonY").onclick = function(){axis = yAxis;};
    document.getElementById("ButtonZ").onclick = function(){axis = zAxis;};
    document.getElementById("ButtonT").onclick = function(){flag = !flag};
    
    gl.uniform4fv(gl.getUniformLocation(program, "ambientProduct"),
       flatten(ambientProduct));
    gl.uniform4fv(gl.getUniformLocation(program, "diffuseProduct"),
       flatten(diffuseProduct) );
    gl.uniform4fv(gl.getUniformLocation(program, "specularProduct"), 
       flatten(specularProduct) );	
    gl.uniform4fv(gl.getUniformLocation(program, "lightPosition"), 
       flatten(lightPosition) );
       
    gl.uniform1f(gl.getUniformLocation(program, 
       "shininess"),materialShininess);
    
    gl.uniformMatrix4fv( gl.getUniformLocation(program, "projectionMatrix"),
       false, flatten(projection));


    canvas.addEventListener("mousedown", function(event){
        
        gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
        gl.clear( gl.COLOR_BUFFER_BIT);
        gl.uniform3fv(thetaLoc, theta);
        for(var i=0; i<6; i++) {
            gl.uniform1i(gl.getUniformLocation(program, "i"), i+1);
            gl.drawArrays( gl.TRIANGLES, 6*i, 6 );
        }
        var x = event.clientX;
        var y = canvas.height -event.clientY;
          
        gl.readPixels(x, y, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, color);

      if (color[0] == 255) {
        if (color[1] == 255) {
          elt.innerHTML = "<div> cyan </div>";
        } else if (color[2] == 255) {
          elt.innerHTML = "<div> magenta </div>";
        } else {
          elt.innerHTML = "<div> red </div>";
        }
      } else if (color[1] == 255) {
        if (color[2] == 255) {
          elt.innerHTML = "<div> blue </div>";
        } else {
          elt.innerHTML = "<div> yellow </div>";
        }
      } else if (color[2] == 255) {
        elt.innerHTML = "<div> green </div>";
      } else {
        elt.innerHTML = "<div> background </div>";
      }

        // Real render
        gl.bindFramebuffer(gl.FRAMEBUFFER, null);

        gl.uniform1i(gl.getUniformLocation(program, "i"), 0);
        gl.clear( gl.COLOR_BUFFER_BIT );
        gl.uniform3fv(thetaLoc, theta);
        gl.drawArrays(gl.TRIANGLES, 0, 36);

    }); 
          
    render();
}

var render = function(){
    gl.clear( gl.COLOR_BUFFER_BIT );
    if(flag) theta[axis] += 2.0;
    modelView = mat4();
    modelView = mult(modelView, rotate(theta[xAxis], [1, 0, 0] ));
    modelView = mult(modelView, rotate(theta[yAxis], [0, 1, 0] ));
    modelView = mult(modelView, rotate(theta[zAxis], [0, 0, 1] ));
    
    gl.uniformMatrix4fv( gl.getUniformLocation(program,
            "modelViewMatrix"), false, flatten(modelView) );

    gl.uniform1i(gl.getUniformLocation(program, "i"),0);
    gl.drawArrays( gl.TRIANGLES, 0, 36 );

    requestAnimFrame(render);
}
            
          
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