chunkyguy · July 2, 2013 11:15
diff --git a/gistfile1.html b/gistfile1.html
 <html>

 <head>
 <title>Texture Coordinates</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 vec2 vTextureCoord;

    uniform sampler2D uSampler;

    void main(void) {
        gl_FragColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));
    }
 </script>

 <script id="shader-vs" type="x-shader/x-vertex">
    attribute vec3 aVertexPosition;
    attribute vec2 aTextureCoord;

    uniform mat4 uMVMatrix;
    uniform mat4 uPMatrix;

    varying vec2 vTextureCoord;


    void main(void) {
        gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
        vTextureCoord = aTextureCoord;
    }
 </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.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "aTextureCoord");
        gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);

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

    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 positionBuffer;
    var textureCoordBuffer;
    
    function initBuffers() {
      positionBuffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
        vertices = [
            -1.0, -1.0,  1.0,
             1.0, -1.0,  1.0,
            -1.0,  1.0,  1.0,
            1.0,  1.0,  1.0
        ];
        gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
        positionBuffer.itemSize = 3;
        positionBuffer.numItems = 4;

        textureCoordBuffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, textureCoordBuffer);
        var textureCoords = [
          0.0, 1.0,
          1.0, 1.0,
          0.0, 0.0,
          1.0, 0.0
        ];
        gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
        textureCoordBuffer.itemSize = 2;
        textureCoordBuffer.numItems = 4;
    }

    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.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
        gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);
        gl.bindTexture(gl.TEXTURE_2D, null);
    }


    var neheTexture;

    function initTexture() {
        neheTexture = gl.createTexture();
        neheTexture.image = new Image();
        neheTexture.image.onload = function () {
            handleLoadedTexture(neheTexture)
        }

        neheTexture.image.src = "images/coolguy.png";
    }

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

        mat4.perspective(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0, pMatrix);

        mat4.identity(mvMatrix);

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

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

        gl.bindBuffer(gl.ARRAY_BUFFER, textureCoordBuffer);
        gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, textureCoordBuffer.itemSize, gl.FLOAT, false, 0, 0);

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

        setMatrixUniforms();
        gl.drawArrays(gl.TRIANGLE_STRIP, 0, positionBuffer.numItems);
    }


    var lastTime = 0;

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

            xRot += (90 * elapsed) / 1000.0;
            yRot += (90 * elapsed) / 1000.0;
            zRot += (90 * elapsed) / 1000.0;
        }
        lastTime = timeNow;
    }


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


    function webGLStart() {
        var canvas = document.getElementById("lesson05-canvas");
        initGL(canvas);
        initShaders();
        initBuffers();
        initTexture();

        gl.clearColor(0.5, 0.5, 0.5, 1.0);
        gl.enable(gl.DEPTH_TEST);

 //        drawScene();
        tick();
    }


 </script>


 </head>


 <body onload="webGLStart();">
    <canvas id="lesson05-canvas" style="border: none;" width="500" height="500"></canvas>
 </body>

 </html>
	<html>

	<head>
	<title>Texture Coordinates</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 vec2 vTextureCoord;

	uniform sampler2D uSampler;

	void main(void) {
	gl_FragColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));
	}
	</script>

	<script id="shader-vs" type="x-shader/x-vertex">
	attribute vec3 aVertexPosition;
	attribute vec2 aTextureCoord;

	uniform mat4 uMVMatrix;
	uniform mat4 uPMatrix;

	varying vec2 vTextureCoord;


	void main(void) {
	gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
	vTextureCoord = aTextureCoord;
	}
	</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.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "aTextureCoord");
	gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);

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

	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 positionBuffer;
	var textureCoordBuffer;

	function initBuffers() {
	positionBuffer = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
	vertices = [
	-1.0, -1.0, 1.0,
	1.0, -1.0, 1.0,
	-1.0, 1.0, 1.0,
	1.0, 1.0, 1.0
	];
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
	positionBuffer.itemSize = 3;
	positionBuffer.numItems = 4;

	textureCoordBuffer = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, textureCoordBuffer);
	var textureCoords = [
	0.0, 1.0,
	1.0, 1.0,
	0.0, 0.0,
	1.0, 0.0
	];
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
	textureCoordBuffer.itemSize = 2;
	textureCoordBuffer.numItems = 4;
	}

	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.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);
	gl.bindTexture(gl.TEXTURE_2D, null);
	}


	var neheTexture;

	function initTexture() {
	neheTexture = gl.createTexture();
	neheTexture.image = new Image();
	neheTexture.image.onload = function () {
	handleLoadedTexture(neheTexture)
	}

	neheTexture.image.src = "images/coolguy.png";
	}

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

	mat4.perspective(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0, pMatrix);

	mat4.identity(mvMatrix);

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

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

	gl.bindBuffer(gl.ARRAY_BUFFER, textureCoordBuffer);
	gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, textureCoordBuffer.itemSize, gl.FLOAT, false, 0, 0);

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

	setMatrixUniforms();
	gl.drawArrays(gl.TRIANGLE_STRIP, 0, positionBuffer.numItems);
	}


	var lastTime = 0;

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

	xRot += (90 * elapsed) / 1000.0;
	yRot += (90 * elapsed) / 1000.0;
	zRot += (90 * elapsed) / 1000.0;
	}
	lastTime = timeNow;
	}


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


	function webGLStart() {
	var canvas = document.getElementById("lesson05-canvas");
	initGL(canvas);
	initShaders();
	initBuffers();
	initTexture();

	gl.clearColor(0.5, 0.5, 0.5, 1.0);
	gl.enable(gl.DEPTH_TEST);

	// drawScene();
	tick();
	}


	</script>


	</head>


	<body onload="webGLStart();">
	<canvas id="lesson05-canvas" style="border: none;" width="500" height="500"></canvas>
	</body>

	</html>