Websites/webkit.org/blog-files/webgl/SpinningBox.html - platform/external/chromium_org/third_party/WebKit - Git at Google

 <!DOCTYPE html>
 <!--
 /*
  * Copyright (C) 2009 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
  -->
 <html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
 <title>Spinning WebGL Box</title>

 <script src="resources/J3DI.js"> </script>
 <script src="resources/J3DIMath.js" type="text/javascript"> </script>
 <script id="vshader" type="x-shader/x-vertex">
     uniform mat4 u_modelViewProjMatrix;
     uniform mat4 u_normalMatrix;
     uniform vec3 lightDir;

     attribute vec3 vNormal;
     attribute vec4 vColor;
     attribute vec4 vPosition;

     varying float v_Dot;
     varying vec4 v_Color;

     void main()
     {
         gl_Position = u_modelViewProjMatrix * vPosition;
         v_Color = vColor;
         vec4 transNormal = u_normalMatrix * vec4(vNormal, 1);
         v_Dot = max(dot(transNormal.xyz, lightDir), 0.0);
     }
 </script>

 <script id="fshader" type="x-shader/x-fragment">
 #ifdef GL_ES
     precision mediump float;
 #endif

     varying float v_Dot;
     varying vec4 v_Color;

     void main()
     {
         gl_FragColor = vec4(v_Color.xyz * v_Dot, v_Color.a);
     }
 </script>

 <script>
     function init()
     {
         // Initialize
         var gl = initWebGL(
             // The id of the Canvas Element
             "example",
             // The ids of the vertex and fragment shaders
             "vshader", "fshader",
             // The vertex attribute names used by the shaders.
             // The order they appear here corresponds to their index
             // used later.
             [ "vNormal", "vColor", "vPosition"],
             // The clear color and depth values
             [ 0, 0, 0, 1 ], 10000);

         gl.console.log("Starting init...");

         // Set up a uniform variable for the shaders
         gl.uniform3f(gl.getUniformLocation(gl.program, "lightDir"), 0, 0, 1);

         // Create a box. On return 'gl' contains a 'box' property with
         // the BufferObjects containing the arrays for vertices,
         // normals, texture coords, and indices.
         gl.box = makeBox(gl);

         // Set up the array of colors for the cube's faces
         var colors = new Uint8Array(
             [  0, 0, 1, 1,   0, 0, 1, 1,   0, 0, 1, 1,   0, 0, 1, 1,     // v0-v1-v2-v3 front
                1, 0, 0, 1,   1, 0, 0, 1,   1, 0, 0, 1,   1, 0, 0, 1,     // v0-v3-v4-v5 right
                0, 1, 0, 1,   0, 1, 0, 1,   0, 1, 0, 1,   0, 1, 0, 1,     // v0-v5-v6-v1 top
                1, 1, 0, 1,   1, 1, 0, 1,   1, 1, 0, 1,   1, 1, 0, 1,     // v1-v6-v7-v2 left
                1, 0, 1, 1,   1, 0, 1, 1,   1, 0, 1, 1,   1, 0, 1, 1,     // v7-v4-v3-v2 bottom
                0, 1, 1, 1,   0, 1, 1, 1,   0, 1, 1, 1,   0, 1, 1, 1 ]    // v4-v7-v6-v5 back
                                                 );

         // Set up the vertex buffer for the colors
         gl.box.colorObject = gl.createBuffer();
         gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.colorObject);
         gl.bufferData(gl.ARRAY_BUFFER, colors, gl.STATIC_DRAW);

         // Create some matrices to use later and save their locations in the shaders
         gl.mvMatrix = new J3DIMatrix4();
         gl.u_normalMatrixLoc = gl.getUniformLocation(gl.program, "u_normalMatrix");
         gl.normalMatrix = new J3DIMatrix4();
         gl.u_modelViewProjMatrixLoc =
                 gl.getUniformLocation(gl.program, "u_modelViewProjMatrix");
         gl.mvpMatrix = new J3DIMatrix4();

         // Enable all of the vertex attribute arrays.
         gl.enableVertexAttribArray(0);
         gl.enableVertexAttribArray(1);
         gl.enableVertexAttribArray(2);

         // Set up all the vertex attributes for vertices, normals and colors
         gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.vertexObject);
         gl.vertexAttribPointer(2, 3, gl.FLOAT, false, 0, 0);

         gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.normalObject);
         gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

         gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.colorObject);
         gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, false, 0, 0);

         // Bind the index array
         gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, gl.box.indexObject);

         return gl;
     }

     width = -1;
     height = -1;

     function reshape(gl)
     {
         var canvas = document.getElementById('example');
         var windowWidth = window.innerWidth - 20;
         var windowHeight = window.innerHeight - 40;
         if (windowWidth == width && windowHeight == height)
             return;

         width = windowWidth;
         height = windowHeight;
         canvas.width = width;
         canvas.height = height;

         // Set the viewport and projection matrix for the scene
         gl.viewport(0, 0, width, height);
         gl.perspectiveMatrix = new J3DIMatrix4();
         gl.perspectiveMatrix.perspective(30, width/height, 1, 10000);
         gl.perspectiveMatrix.lookat(0, 0, 7, 0, 0, 0, 0, 1, 0);
     }

     function drawPicture(gl)
     {
         // Make sure the canvas is sized correctly.
         reshape(gl);

         // Clear the canvas
         gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

         // Make a model/view matrix.
         gl.mvMatrix.makeIdentity();
         gl.mvMatrix.rotate(20, 1,0,0);
         gl.mvMatrix.rotate(currentAngle, 0,1,0);

         // Construct the normal matrix from the model-view matrix and pass it in
         gl.normalMatrix.load(gl.mvMatrix);
         gl.normalMatrix.invert();
         gl.normalMatrix.transpose();
         gl.normalMatrix.setUniform(gl, gl.u_normalMatrixLoc, false);

         // Construct the model-view * projection matrix and pass it in
         gl.mvpMatrix.load(gl.perspectiveMatrix);
         gl.mvpMatrix.multiply(gl.mvMatrix);
         gl.mvpMatrix.setUniform(gl, gl.u_modelViewProjMatrixLoc, false);

         // Draw the cube
         gl.drawElements(gl.TRIANGLES, gl.box.numIndices, gl.UNSIGNED_BYTE, 0);

         // Finish up.
         gl.flush();

         // Show the framerate
         framerate.snapshot();

         currentAngle += incAngle;
         if (currentAngle > 360)
             currentAngle -= 360;
     }

     function start()
     {
         var c = document.getElementById("example");
         var w = Math.floor(window.innerWidth * 0.9);
         var h = Math.floor(window.innerHeight * 0.9);

         c.width = w;
         c.height = h;

         var gl = init();
         currentAngle = 0;
         incAngle = 0.5;
         framerate = new Framerate("framerate");
         setInterval(function() { drawPicture(gl) }, 10);
     }
 </script>
 <style type="text/css">
     canvas {
         //border: 2px solid black;
     }
     .text {
         position:absolute;
         top:100px;
         left:20px;
         font-size:2em;
         color: blue;
     }
 </style>
 </head>

 <body onload="start()">
 <canvas id="example">
     If you're seeing this your web browser doesn't support the &lt;canvas>&gt; element. Ouch!
 </canvas>
 <div class="text">This is some text over the canvas</div>
 <div id="framerate"></div>
 </body>

 </html>
	<!DOCTYPE html>
	<!--
	/*
	* Copyright (C) 2009 Apple Inc. All Rights Reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/
	-->
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
	<title>Spinning WebGL Box</title>

	<script src="resources/J3DI.js"> </script>
	<script src="resources/J3DIMath.js" type="text/javascript"> </script>
	<script id="vshader" type="x-shader/x-vertex">
	uniform mat4 u_modelViewProjMatrix;
	uniform mat4 u_normalMatrix;
	uniform vec3 lightDir;

	attribute vec3 vNormal;
	attribute vec4 vColor;
	attribute vec4 vPosition;

	varying float v_Dot;
	varying vec4 v_Color;

	void main()
	{
	gl_Position = u_modelViewProjMatrix * vPosition;
	v_Color = vColor;
	vec4 transNormal = u_normalMatrix * vec4(vNormal, 1);
	v_Dot = max(dot(transNormal.xyz, lightDir), 0.0);
	}
	</script>

	<script id="fshader" type="x-shader/x-fragment">
	#ifdef GL_ES
	precision mediump float;
	#endif

	varying float v_Dot;
	varying vec4 v_Color;

	void main()
	{
	gl_FragColor = vec4(v_Color.xyz * v_Dot, v_Color.a);
	}
	</script>

	<script>
	function init()
	{
	// Initialize
	var gl = initWebGL(
	// The id of the Canvas Element
	"example",
	// The ids of the vertex and fragment shaders
	"vshader", "fshader",
	// The vertex attribute names used by the shaders.
	// The order they appear here corresponds to their index
	// used later.
	[ "vNormal", "vColor", "vPosition"],
	// The clear color and depth values
	[ 0, 0, 0, 1 ], 10000);

	gl.console.log("Starting init...");

	// Set up a uniform variable for the shaders
	gl.uniform3f(gl.getUniformLocation(gl.program, "lightDir"), 0, 0, 1);

	// Create a box. On return 'gl' contains a 'box' property with
	// the BufferObjects containing the arrays for vertices,
	// normals, texture coords, and indices.
	gl.box = makeBox(gl);

	// Set up the array of colors for the cube's faces
	var colors = new Uint8Array(
	[ 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, // v0-v1-v2-v3 front
	1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, // v0-v3-v4-v5 right
	0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, // v0-v5-v6-v1 top
	1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, // v1-v6-v7-v2 left
	1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, // v7-v4-v3-v2 bottom
	0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1 ] // v4-v7-v6-v5 back
	);

	// Set up the vertex buffer for the colors
	gl.box.colorObject = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.colorObject);
	gl.bufferData(gl.ARRAY_BUFFER, colors, gl.STATIC_DRAW);

	// Create some matrices to use later and save their locations in the shaders
	gl.mvMatrix = new J3DIMatrix4();
	gl.u_normalMatrixLoc = gl.getUniformLocation(gl.program, "u_normalMatrix");
	gl.normalMatrix = new J3DIMatrix4();
	gl.u_modelViewProjMatrixLoc =
	gl.getUniformLocation(gl.program, "u_modelViewProjMatrix");
	gl.mvpMatrix = new J3DIMatrix4();

	// Enable all of the vertex attribute arrays.
	gl.enableVertexAttribArray(0);
	gl.enableVertexAttribArray(1);
	gl.enableVertexAttribArray(2);

	// Set up all the vertex attributes for vertices, normals and colors
	gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.vertexObject);
	gl.vertexAttribPointer(2, 3, gl.FLOAT, false, 0, 0);

	gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.normalObject);
	gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

	gl.bindBuffer(gl.ARRAY_BUFFER, gl.box.colorObject);
	gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, false, 0, 0);

	// Bind the index array
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, gl.box.indexObject);

	return gl;
	}

	width = -1;
	height = -1;

	function reshape(gl)
	{
	var canvas = document.getElementById('example');
	var windowWidth = window.innerWidth - 20;
	var windowHeight = window.innerHeight - 40;
	if (windowWidth == width && windowHeight == height)
	return;

	width = windowWidth;
	height = windowHeight;
	canvas.width = width;
	canvas.height = height;

	// Set the viewport and projection matrix for the scene
	gl.viewport(0, 0, width, height);
	gl.perspectiveMatrix = new J3DIMatrix4();
	gl.perspectiveMatrix.perspective(30, width/height, 1, 10000);
	gl.perspectiveMatrix.lookat(0, 0, 7, 0, 0, 0, 0, 1, 0);
	}

	function drawPicture(gl)
	{
	// Make sure the canvas is sized correctly.
	reshape(gl);

	// Clear the canvas
	gl.clear(gl.COLOR_BUFFER_BIT \| gl.DEPTH_BUFFER_BIT);

	// Make a model/view matrix.
	gl.mvMatrix.makeIdentity();
	gl.mvMatrix.rotate(20, 1,0,0);
	gl.mvMatrix.rotate(currentAngle, 0,1,0);

	// Construct the normal matrix from the model-view matrix and pass it in
	gl.normalMatrix.load(gl.mvMatrix);
	gl.normalMatrix.invert();
	gl.normalMatrix.transpose();
	gl.normalMatrix.setUniform(gl, gl.u_normalMatrixLoc, false);

	// Construct the model-view * projection matrix and pass it in
	gl.mvpMatrix.load(gl.perspectiveMatrix);
	gl.mvpMatrix.multiply(gl.mvMatrix);
	gl.mvpMatrix.setUniform(gl, gl.u_modelViewProjMatrixLoc, false);

	// Draw the cube
	gl.drawElements(gl.TRIANGLES, gl.box.numIndices, gl.UNSIGNED_BYTE, 0);

	// Finish up.
	gl.flush();

	// Show the framerate
	framerate.snapshot();

	currentAngle += incAngle;
	if (currentAngle > 360)
	currentAngle -= 360;
	}

	function start()
	{
	var c = document.getElementById("example");
	var w = Math.floor(window.innerWidth * 0.9);
	var h = Math.floor(window.innerHeight * 0.9);

	c.width = w;
	c.height = h;

	var gl = init();
	currentAngle = 0;
	incAngle = 0.5;
	framerate = new Framerate("framerate");
	setInterval(function() { drawPicture(gl) }, 10);
	}
	</script>
	<style type="text/css">
	canvas {
	//border: 2px solid black;
	}
	.text {
	position:absolute;
	top:100px;
	left:20px;
	font-size:2em;
	color: blue;
	}
	</style>
	</head>

	<body onload="start()">
	<canvas id="example">
	If you're seeing this your web browser doesn't support the <canvas>> element. Ouch!
	</canvas>
	<div class="text">This is some text over the canvas</div>
	<div id="framerate"></div>
	</body>

	</html>