amadeus/index.html

## index.html
<html>

<head>
<title>Learning WebGL &mdash; lesson 3</title>
<meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">

<script type="text/javascript" src="glMatrix-0.9.5.min.js"></script>
<script type="text/javascript" src="webgl-utils.js"></script>

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

    varying vec4 vColor;

    void main(void) {
        gl_FragColor = vColor;
    }
</script>

<script id="shader-vs" type="x-shader/x-vertex">
    attribute vec3 aVertexPosition;
    attribute vec4 aVertexColor;

    uniform mat4 uMVMatrix;
    uniform mat4 uPMatrix;

    varying vec4 vColor;

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


<script type="text/javascript">

    var gl;

    function initGL(canvas) {
        try {
            gl = canvas.getContext("experimental-webgl");
            gl.viewportWidth = canvas.width;
            gl.viewportHeight = canvas.height;
        } catch (e) {
        }
        if (!gl) {
            alert("Could not initialise WebGL, sorry :-(");
        }
    }


    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;

    function initShaders() {
        var fragmentShader = getShader(gl, "shader-fs");
        var vertexShader = getShader(gl, "shader-vs");

        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);

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

        shaderProgram.vertexColorAttribute = gl.getAttribLocation(shaderProgram, "aVertexColor");
        gl.enableVertexAttribArray(shaderProgram.vertexColorAttribute);

        shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
        shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
    }


    var mvMatrix = mat4.create();
    var mvMatrixStack = [];
    var pMatrix = mat4.create();

    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);
    }


    function degToRad(degrees) {
        return degrees * Math.PI / 180;
    }


    var triangleVertexPositionBuffer;
    var triangleVertexColorBuffer;
    var squareVertexPositionBuffer;
    var squareVertexColorBuffer;

    function initBuffers() {
        triangleVertexPositionBuffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexPositionBuffer);
        var vertices = [
             0.0,  1.0,  0.0,
            -1.0, -1.0,  0.0,
             1.0, -1.0,  0.0
        ];
        gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
        triangleVertexPositionBuffer.itemSize = 3;
        triangleVertexPositionBuffer.numItems = 3;

        triangleVertexColorBuffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexColorBuffer);
        var colors = [
            1.0, 0.0, 0.0, 1.0,
            0.0, 1.0, 0.0, 1.0,
            0.0, 0.0, 1.0, 1.0,
        ];
        gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors), gl.STATIC_DRAW);
        triangleVertexColorBuffer.itemSize = 4;
        triangleVertexColorBuffer.numItems = 3;


        squareVertexPositionBuffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexPositionBuffer);
        vertices = [
             1.0,  1.0,  0.0,
            -1.0,  1.0,  0.0,
             1.0, -1.0,  0.0,
            -1.0, -1.0,  0.0
            ];
        gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
        squareVertexPositionBuffer.itemSize = 3;
        squareVertexPositionBuffer.numItems = 4;

        squareVertexColorBuffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexColorBuffer);
        colors = []
        for (var i=0; i < 4; i++) {
            colors = colors.concat([0.5, 0.5, 1.0, 1.0]);
        }
        gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors), gl.STATIC_DRAW);
        squareVertexColorBuffer.itemSize = 4;
        squareVertexColorBuffer.numItems = 4;
    }


    var rTri = 0;
    var rSquare = 0;

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

        // Set the projection matrix
        mat4.perspective(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0, pMatrix);

        // Reset the model-view matrix
        mat4.identity(mvMatrix);

        // Move the mv matrix to the left 1.5 unites, and away 7 units
        mat4.translate(mvMatrix, [-1.5, 0.0, -7.0]);

        // Save the model view matrix to the stack
        mvPushMatrix();
        // Rotate the model-view matrix
        mat4.rotate(mvMatrix, degToRad(rTri), [0, 1, 0]);

        // Bind the triangle vertex data
        gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexPositionBuffer);
        // Setup the attribute pointer
        gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, triangleVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);

        // Bind the triangle color data
        gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexColorBuffer);
        // Setup the attribute pointer
        gl.vertexAttribPointer(shaderProgram.vertexColorAttribute, triangleVertexColorBuffer.itemSize, gl.FLOAT, false, 0, 0);

        // Apply projection and model-view matrices
        gl.uniformMatrix4fv(shaderProgram.pMatrixUniform,  false, pMatrix);
        gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix);

        // Draw the triangle
        gl.drawArrays(gl.TRIANGLE_FAN, 0, triangleVertexPositionBuffer.numItems);
        mvPopMatrix();


        mat4.translate(mvMatrix, [3.0, 0.0, 0.0]);

        mvPushMatrix();
        mat4.rotate(mvMatrix, degToRad(rSquare), [1, 0, 0]);

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

        gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexColorBuffer);
        gl.vertexAttribPointer(shaderProgram.vertexColorAttribute, squareVertexColorBuffer.itemSize, gl.FLOAT, false, 0, 0);

        gl.uniformMatrix4fv(shaderProgram.pMatrixUniform,  false, pMatrix);
        gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix);

        gl.drawArrays(gl.TRIANGLE_STRIP, 0, squareVertexPositionBuffer.numItems);

        mvPopMatrix();
    }


    var lastTime = 0;

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

            rTri += (90 * elapsed) / 1000.0;
            rSquare += (75 * elapsed) / 1000.0;
        }
        lastTime = timeNow;
    }


    function tick() {
        requestAnimFrame(tick);
        drawScene();
        animate();
    }


    function webGLStart() {
        var canvas = document.getElementById("lesson03-canvas");
        initGL(canvas);
        initShaders()
        initBuffers();

        gl.clearColor(0.0, 0.0, 0.0, 1.0);
        gl.enable(gl.DEPTH_TEST);

        tick();
    }

</script>

</head>


<body onload="webGLStart();">
    <a href="http://learningwebgl.com/blog/?p=239">&lt;&lt; Back to Lesson 3</a><br />

    <canvas id="lesson03-canvas" style="border: none;" width="500" height="500"></canvas>

    <br/>
    <a href="http://learningwebgl.com/blog/?p=239">&lt;&lt; Back to Lesson 3</a><br />
</body>

</html>
	<html>

	<head>
	<title>Learning WebGL — lesson 3</title>
	<meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">

	<script type="text/javascript" src="glMatrix-0.9.5.min.js"></script>
	<script type="text/javascript" src="webgl-utils.js"></script>

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

	varying vec4 vColor;

	void main(void) {
	gl_FragColor = vColor;
	}
	</script>

	<script id="shader-vs" type="x-shader/x-vertex">
	attribute vec3 aVertexPosition;
	attribute vec4 aVertexColor;

	uniform mat4 uMVMatrix;
	uniform mat4 uPMatrix;

	varying vec4 vColor;

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


	<script type="text/javascript">

	var gl;

	function initGL(canvas) {
	try {
	gl = canvas.getContext("experimental-webgl");
	gl.viewportWidth = canvas.width;
	gl.viewportHeight = canvas.height;
	} catch (e) {
	}
	if (!gl) {
	alert("Could not initialise WebGL, sorry :-(");
	}
	}


	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;

	function initShaders() {
	var fragmentShader = getShader(gl, "shader-fs");
	var vertexShader = getShader(gl, "shader-vs");

	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);

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

	shaderProgram.vertexColorAttribute = gl.getAttribLocation(shaderProgram, "aVertexColor");
	gl.enableVertexAttribArray(shaderProgram.vertexColorAttribute);

	shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
	shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
	}


	var mvMatrix = mat4.create();
	var mvMatrixStack = [];
	var pMatrix = mat4.create();

	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);
	}


	function degToRad(degrees) {
	return degrees * Math.PI / 180;
	}


	var triangleVertexPositionBuffer;
	var triangleVertexColorBuffer;
	var squareVertexPositionBuffer;
	var squareVertexColorBuffer;

	function initBuffers() {
	triangleVertexPositionBuffer = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexPositionBuffer);
	var vertices = [
	0.0, 1.0, 0.0,
	-1.0, -1.0, 0.0,
	1.0, -1.0, 0.0
	];
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
	triangleVertexPositionBuffer.itemSize = 3;
	triangleVertexPositionBuffer.numItems = 3;

	triangleVertexColorBuffer = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexColorBuffer);
	var colors = [
	1.0, 0.0, 0.0, 1.0,
	0.0, 1.0, 0.0, 1.0,
	0.0, 0.0, 1.0, 1.0,
	];
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors), gl.STATIC_DRAW);
	triangleVertexColorBuffer.itemSize = 4;
	triangleVertexColorBuffer.numItems = 3;


	squareVertexPositionBuffer = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexPositionBuffer);
	vertices = [
	1.0, 1.0, 0.0,
	-1.0, 1.0, 0.0,
	1.0, -1.0, 0.0,
	-1.0, -1.0, 0.0
	];
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
	squareVertexPositionBuffer.itemSize = 3;
	squareVertexPositionBuffer.numItems = 4;

	squareVertexColorBuffer = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexColorBuffer);
	colors = []
	for (var i=0; i < 4; i++) {
	colors = colors.concat([0.5, 0.5, 1.0, 1.0]);
	}
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors), gl.STATIC_DRAW);
	squareVertexColorBuffer.itemSize = 4;
	squareVertexColorBuffer.numItems = 4;
	}



	var rTri = 0;
	var rSquare = 0;

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

	// Set the projection matrix
	mat4.perspective(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0, pMatrix);

	// Reset the model-view matrix
	mat4.identity(mvMatrix);

	// Move the mv matrix to the left 1.5 unites, and away 7 units
	mat4.translate(mvMatrix, [-1.5, 0.0, -7.0]);

	// Save the model view matrix to the stack
	mvPushMatrix();
	// Rotate the model-view matrix
	mat4.rotate(mvMatrix, degToRad(rTri), [0, 1, 0]);

	// Bind the triangle vertex data
	gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexPositionBuffer);
	// Setup the attribute pointer
	gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, triangleVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);

	// Bind the triangle color data
	gl.bindBuffer(gl.ARRAY_BUFFER, triangleVertexColorBuffer);
	// Setup the attribute pointer
	gl.vertexAttribPointer(shaderProgram.vertexColorAttribute, triangleVertexColorBuffer.itemSize, gl.FLOAT, false, 0, 0);

	// Apply projection and model-view matrices
	gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, pMatrix);
	gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix);

	// Draw the triangle
	gl.drawArrays(gl.TRIANGLE_FAN, 0, triangleVertexPositionBuffer.numItems);
	mvPopMatrix();


	mat4.translate(mvMatrix, [3.0, 0.0, 0.0]);

	mvPushMatrix();
	mat4.rotate(mvMatrix, degToRad(rSquare), [1, 0, 0]);

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

	gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexColorBuffer);
	gl.vertexAttribPointer(shaderProgram.vertexColorAttribute, squareVertexColorBuffer.itemSize, gl.FLOAT, false, 0, 0);

	gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, pMatrix);
	gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix);

	gl.drawArrays(gl.TRIANGLE_STRIP, 0, squareVertexPositionBuffer.numItems);

	mvPopMatrix();
	}


	var lastTime = 0;

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

	rTri += (90 * elapsed) / 1000.0;
	rSquare += (75 * elapsed) / 1000.0;
	}
	lastTime = timeNow;
	}


	function tick() {
	requestAnimFrame(tick);
	drawScene();
	animate();
	}


	function webGLStart() {
	var canvas = document.getElementById("lesson03-canvas");
	initGL(canvas);
	initShaders()
	initBuffers();

	gl.clearColor(0.0, 0.0, 0.0, 1.0);
	gl.enable(gl.DEPTH_TEST);

	tick();
	}

	</script>

	</head>


	<body onload="webGLStart();">
	<a href="http://learningwebgl.com/blog/?p=239"><< Back to Lesson 3</a><br />

	<canvas id="lesson03-canvas" style="border: none;" width="500" height="500"></canvas>

	<br/>
	<a href="http://learningwebgl.com/blog/?p=239"><< Back to Lesson 3</a><br />
	</body>

	</html>