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

varying vec3 R;
attribute vec4 vPosition;
attribute vec4 vNormal;
attribute float vDoReflect;

uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
uniform mat3 normalMatrix;

void main()
{     
    //vec3 eyePos  = normalize((modelViewMatrix*vPosition).xyz);
    vec3 eyePos  = (modelViewMatrix*vPosition).xyz;

    vec3 N = normalize(normalMatrix*vNormal.xyz);
    //vec3 N = normalMatrix*vNormal.xyz;
    
    if (vDoReflect >= 0.5) {
      gl_Position = projectionMatrix*modelViewMatrix*vPosition;
      R = reflect(eyePos, N);
    } else {
      gl_Position = projectionMatrix*vPosition;
      R = vec3(vNormal.x, vNormal.y, -vNormal.z);
    } 
}
</script>

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

precision mediump float;

varying vec3 R;
uniform samplerCube texMap;

void main()
{
    vec4 texColor = textureCube(texMap, R);

    gl_FragColor = texColor;
}
</script>

<p> </p>
<button id = "Button2">Increase theta</button>
<button id = "Button3">Decrease theta</button>
<button id = "Button4">Increase phi</button>
<button id = "Button5">Decrease phi</button>
<p> </p>



<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>

<body>
<canvas id="gl-canvas" width="512" height="512">
Oops ... your browser doesn't support the HTML5 canvas element
</canvas>
</body>
</html>

            
          
!
            
              var canvas;
var gl;
var program;

var numVertices  = 36;

var dr = 5.0 * Math.PI/180.0;
var radius = 3.0;
var theta  = -6.0 * dr;
var phi    = -6.0 * dr;

var near = 0.001;
var far = 1000.0;
var  fovy = 120.0;  // Field-of-view in Y direction angle (in degrees)
var  aspect;       // Viewport aspect ratio


var flag = true;

var red = new Uint8Array([255, 0, 0, 255]);
var green = new Uint8Array([0, 255, 0, 255]);
var blue = new Uint8Array([0, 0, 255, 255]);
var cyan = new Uint8Array([0, 255, 255, 255]);
var magenta = new Uint8Array([255, 0, 255, 255]);
var yellow = new Uint8Array([255, 255, 0, 255]);

var cubeMap;

var pointsArray = [];
var normalsArray = [];
var reflectArray = [];

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 )
];


function configureCubeMap() {

    cubeMap = gl.createTexture();

    gl.bindTexture(gl.TEXTURE_CUBE_MAP, cubeMap);
    gl.texImage2D(gl.TEXTURE_CUBE_MAP_POSITIVE_X ,0,gl.RGBA,
       1,1,0,gl.RGBA,gl.UNSIGNED_BYTE, red);
    gl.texImage2D(gl.TEXTURE_CUBE_MAP_NEGATIVE_X ,0,gl.RGBA,
       1,1,0,gl.RGBA,gl.UNSIGNED_BYTE, green);
    gl.texImage2D(gl.TEXTURE_CUBE_MAP_POSITIVE_Y ,0,gl.RGBA,
       1,1,0,gl.RGBA,gl.UNSIGNED_BYTE, blue);
    gl.texImage2D(gl.TEXTURE_CUBE_MAP_NEGATIVE_Y ,0,gl.RGBA,
       1,1,0,gl.RGBA,gl.UNSIGNED_BYTE, cyan);
    gl.texImage2D(gl.TEXTURE_CUBE_MAP_POSITIVE_Z ,0,gl.RGBA,
       1,1,0,gl.RGBA,gl.UNSIGNED_BYTE, yellow);
    gl.texImage2D(gl.TEXTURE_CUBE_MAP_NEGATIVE_Z ,0,gl.RGBA,
       1,1,0,gl.RGBA,gl.UNSIGNED_BYTE, magenta);
    

    gl.texParameteri(gl.TEXTURE_CUBE_MAP,gl.TEXTURE_MAG_FILTER,gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_CUBE_MAP,gl.TEXTURE_MIN_FILTER,gl.NEAREST);
}

function scaleVertex(scaling, vertex) {
  scaledVertex = scale(scaling, vertex);
  scaledVertex[3] = 1.0;
  return scaledVertex;
}

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

     var t1 = scale(scaling, subtract(vertices[b], vertices[a]));
     var t2 = scale(scaling, subtract(vertices[c], vertices[a]));
     var normal = cross(t1, t2);
     normal[3] = 0.0;

  console.log(scaling);
  console.log(vertices[a]);
  console.log(scaleVertex(scaling, vertices[a]));
     pointsArray.push(scaleVertex(scaling, vertices[a])); 
     normalsArray.push(normal); 
     reflectArray.push(doReflect);

     pointsArray.push(scaleVertex(scaling, vertices[b])); 
     normalsArray.push(normal);
     reflectArray.push(doReflect);

     pointsArray.push(scaleVertex(scaling, vertices[c])); 
     normalsArray.push(normal);
     reflectArray.push(doReflect);
    
     pointsArray.push(scaleVertex(scaling, vertices[a])); 
     normalsArray.push(normal);
     reflectArray.push(doReflect);

     pointsArray.push(scaleVertex(scaling, vertices[c])); 
     normalsArray.push(normal);
     reflectArray.push(doReflect);

     pointsArray.push(scaleVertex(scaling, vertices[d])); 
     normalsArray.push(normal);
     reflectArray.push(doReflect);   
}

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

function init() {
    canvas = document.getElementById( "gl-canvas" );
    
    gl = WebGLUtils.setupWebGL( canvas );
    if ( !gl ) { alert( "WebGL isn't available" ); }

    gl.viewport( 0, 0, canvas.width, canvas.height );
    gl.clearColor( 1.0, 1.0, 1.0, 1.0 );
    
    gl.enable(gl.DEPTH_TEST);

    // Set aspect ratio of canvas
    aspect =  canvas.width/canvas.height;
  
    //
    //  Load shaders and initialize attribute buffers
    //
    program = initShaders( gl, "vertex-shader", "fragment-shader" );
    gl.useProgram( program );
    
    colorCube(1.0, 1.0);
    colorCube(-10.0, 0.0);

    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, 4, 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);
    
    var rBuffer = gl.createBuffer();
    gl.bindBuffer( gl.ARRAY_BUFFER, rBuffer);
    gl.bufferData( gl.ARRAY_BUFFER, flatten(reflectArray), gl.STATIC_DRAW );
    
    var vDoReflect = gl.getAttribLocation( program, "vDoReflect");
    gl.vertexAttribPointer( vDoReflect, 1, gl.FLOAT, false, 0, 0);
    gl.enableVertexAttribArray( vDoReflect);

    //var projectionMatrix = ortho(-2, 2, -2, 2, -10, 10);
    var projectionMatrix = perspective(fovy, aspect, near, far);

    gl.uniformMatrix4fv( gl.getUniformLocation( program, "projectionMatrix" ), false, flatten(projectionMatrix) );

    configureCubeMap();
    gl.activeTexture( gl.TEXTURE0 );
    gl.uniform1i(gl.getUniformLocation(program, "texMap"),0); 
    
    document.getElementById("Button2").onclick = function(){theta += dr;};
    document.getElementById("Button3").onclick = function(){theta -= dr;};
    document.getElementById("Button4").onclick = function(){phi += dr;};
    document.getElementById("Button5").onclick = function(){phi -= dr;};

    render();
}

var render = function(){
    gl.clear( gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
    
    var eye = vec3(radius*Math.sin(theta)*Math.cos(phi), 
        radius*Math.sin(theta)*Math.sin(phi), radius*Math.cos(theta));
    var at = vec3(0.0, 0.0, 0.0);
    var up = vec3(0.0, 1.0, 0.0);
    
    var modelViewMatrix = lookAt(eye, at, up);
  
    gl.uniformMatrix4fv( gl.getUniformLocation(program, "modelViewMatrix"), false, flatten(modelViewMatrix) );
            
    var normalMatrix = [
        vec3(modelViewMatrix[0][0], modelViewMatrix[0][1], modelViewMatrix[0][2]),
        vec3(modelViewMatrix[1][0], modelViewMatrix[1][1], modelViewMatrix[1][2]),
        vec3(modelViewMatrix[2][0], modelViewMatrix[2][1], modelViewMatrix[2][2])
    ];
    
    gl.uniformMatrix3fv(gl.getUniformLocation(program, "normalMatrix"), false, flatten(normalMatrix) );

    gl.drawArrays( gl.TRIANGLES, 0, pointsArray.length );
    requestAnimFrame(render);
}

init();
            
          
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