1. WebGL: a New Platform for 3D Games Advanced Games Programming by Jarek Francik 2011

2. HTML5, Canvas & WebGL Google Chromeok Mozilla Firefoxok, but not today Safaridev version only Operadev version only Internet ExplorerNO!!!

3. HTML5 WebGL Tutorial WebGL Tutorial If nothing visible, try to run with the latest version of Chrome. If it still doesn't help, try to upload to any web server and run through http.

4. Fragment Shader #ifdef GL_ES precision highp float; #endif varying vec4 vColor; void main(void) { gl_FragColor = vColor; }

5. Vertex Shader attribute vec3 aVertexPosition; uniform mat4 uMVMatrix; uniform mat4 uPMatrix; varying vec4 vColor; void main(void) { gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0); vColor = vec4(1.0, 1.0, 1.0, 1.0); }

6. main function (1)

7. main function (2) function main() { // Initialize WebGL context var canvas = document.getElementById("idCanvas"); var gl = canvas.getContext("experimental-webgl"); gl.viewport(0, 0, canvas.width, canvas.height); gl.clearColor(0.0, 0.0, 0.0, 1.0); gl.enable(gl.DEPTH_TEST); //.... // see following slides

8. main function (3) // Initialize Shader Program var txtShaderFrag = document.getElementById("shader-fs").innerText; var txtShaderVert = document.getElementById("shader-vs").innerText; var shaderProgram = gl.createProgram(); var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER); gl.shaderSource(fragmentShader, txtShaderFrag); gl.compileShader(fragmentShader); gl.attachShader(shaderProgram, fragmentShader); var vertexShader = gl.createShader(gl.VERTEX_SHADER); gl.shaderSource(vertexShader, txtShaderVert); gl.compileShader(vertexShader); gl.attachShader(shaderProgram, vertexShader); gl.linkProgram(shaderProgram); gl.useProgram(shaderProgram); gl.enableVertexAttribArray(gl.getAttribLocation(shaderProgram, "aVertexPosition")); gl.enableVertexAttribArray(gl.getAttribLocation(shaderProgram, "aVertexColor")); gl.shaderProgram = shaderProgram;

9. main function (4) // Init Objects initObjects(gl); // Render buffers render(gl); }

10. main function function main() { // Initialize WebGL context var canvas = document.getElementById("idCanvas"); var gl = canvas.getContext("experimental-webgl"); gl.viewport(0, 0, canvas.width, canvas.height); gl.clearColor(0.0, 0.0, 0.0, 1.0); gl.enable(gl.DEPTH_TEST); // Initialize Shader Program var txtShaderFrag = document.getElementById("shader-fs").innerText; var txtShaderVert = document.getElementById("shader-vs").innerText; var shaderProgram = gl.createProgram(); var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER); gl.shaderSource(fragmentShader, txtShaderFrag); gl.compileShader(fragmentShader); gl.attachShader(shaderProgram, fragmentShader); var vertexShader = gl.createShader(gl.VERTEX_SHADER); gl.shaderSource(vertexShader, txtShaderVert); gl.compileShader(vertexShader); gl.attachShader(shaderProgram, vertexShader); gl.linkProgram(shaderProgram); gl.useProgram(shaderProgram); gl.enableVertexAttribArray(gl.getAttribLocation(shaderProgram, "aVertexPosition")); gl.enableVertexAttribArray(gl.getAttribLocation(shaderProgram, "aVertexColor")); gl.shaderProgram = shaderProgram; // Init Objects initObjects(gl); // Render buffers render(gl); }

11. initObjects function initObjects(gl) { var bufVertexPositions = gl.createBuffer(); gl.bindBuffer(gl.ARRAY_BUFFER, bufVertexPositions); var vertices = [ 0.0, 1.0, 0.0, // triangle -1.0, -1.0, 0.0, 1.0, -1.0, 0.0, 1.0, 1.0, 0.0, // square -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); gl.bufVertexPositions = bufVertexPositions; }

12. render (1) function render(gl) { // clear canvas gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); // bind and set the vertex buffer gl.bindBuffer(gl.ARRAY_BUFFER, gl.bufVertexPositions); loc = gl.getAttribLocation(gl.shaderProgram, "aVertexPosition"); gl.vertexAttribPointer(loc, 3, gl.FLOAT, false, 0, 0);

13. render (2) // set-up the view matrix var pMatrix = mat4.create(); mat4.perspective(45, gl.canvas.width / gl.canvas.height, 0.1, 100.0, pMatrix); mat4.translate(pMatrix, [0, 0.0, -7.0]); loc = gl.getUniformLocation(gl.shaderProgram, "uPMatrix"); gl.uniformMatrix4fv(loc, false, pMatrix); // set up the world matrix var mvMatrix = mat4.create(); mat4.identity(mvMatrix); mat4.translate(mvMatrix, [-1.5, 0.0, 0.0]); loc = gl.getUniformLocation(gl.shaderProgram, "uMVMatrix"); gl.uniformMatrix4fv(loc, false, mvMatrix);

14. render (3) // draw the triangle (3 vertices) gl.drawArrays(gl.TRIANGLES, 0, 3); // modify the world matrix mat4.translate(mvMatrix, [3.0, 0.0, 0.0]); loc = gl.getUniformLocation(gl.shaderProgram, "uMVMatrix"); gl.uniformMatrix4fv(loc, false, mvMatrix); // draw the square (4 vertices, starting from no 3) gl.drawArrays(gl.TRIANGLE_STRIP, 3, 4); }

15. render function render(gl) { // clear canvas gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); // bind and set the vertex buffer gl.bindBuffer(gl.ARRAY_BUFFER, gl.bufVertexPositions); loc = gl.getAttribLocation(gl.shaderProgram, "aVertexPosition"); gl.vertexAttribPointer(loc, 3, gl.FLOAT, false, 0, 0); // set-up the view matrix var pMatrix = mat4.create(); mat4.perspective(45, gl.canvas.width / gl.canvas.height, 0.1, 100.0, pMatrix); mat4.translate(pMatrix, [0, 0.0, -7.0]); loc = gl.getUniformLocation(gl.shaderProgram, "uPMatrix"); gl.uniformMatrix4fv(loc, false, pMatrix); // set up the world matrix var mvMatrix = mat4.create(); mat4.identity(mvMatrix); mat4.translate(mvMatrix, [-1.5, 0.0, 0.0]); loc = gl.getUniformLocation(gl.shaderProgram, "uMVMatrix"); gl.uniformMatrix4fv(loc, false, mvMatrix); // draw the triangle (3 vertices) gl.drawArrays(gl.TRIANGLES, 0, 3); // modify the world matrix mat4.translate(mvMatrix, [3.0, 0.0, 0.0]); loc = gl.getUniformLocation(gl.shaderProgram, "uMVMatrix"); gl.uniformMatrix4fv(loc, false, mvMatrix); // draw the square (4 vertices, starting from no 3) gl.drawArrays(gl.TRIANGLE_STRIP, 3, 4); }

16. animate (1) 1.Add (before render): var angle = 0; 2.Add (in world matrix configuration): mat4.rotateY(mvMatrix, angle); 3.Replace render() call in main() with: // Start animation loop animate(gl);

17. animate (2) function animate(gl) { window.webkitRequestAnimationFrame(function() { animate(gl); }); render(gl); angle += 0.025; }

18. Next Stages 1.(Animated Triangle and Square) 2.Added Colours 3.Added 3D: Pyramid and Cube 4.Added Texture 5.Added Lighting (not covered today)

19. Three.js: HTML WebGL/Three.js Tutorial

20. Three.js: javascript (1) var camera, scene, renderer, sphere; function main() { // create a renderer, camera, and scene renderer = new THREE.WebGLRenderer(); renderer.setSize( window.innerWidth, window.innerHeight ); camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 10000); camera.position.z = 600; scene = new THREE.Scene();

21. Three.js: javascript (2) var texture = THREE.ImageUtils.loadTexture( "land_ocean_ice_cloud_2048.jpg" ); sphere = new THREE.Mesh(new THREE.SphereGeometry(200, 100, 100), new THREE.MeshBasicMaterial( { map:texture } )); scene.add(sphere); // add lighting var light = new THREE.DirectionalLight(0xFFFFFF); light.position.x = 150; light.position.y = 250; light.position.z = 150; scene.add(light); // attach the scene to the DOM document.getElementById("container").appendChild(renderer.domElement); animate(); }

22. Three.js: javascript function animate() { window.webkitRequestAnimationFrame(animate); renderer.render(scene, camera); }

23. Three.js: javascript var camera, scene, renderer, sphere; function main() { // create a renderer, camera, and scene renderer = new THREE.WebGLRenderer(); renderer.setSize( window.innerWidth, window.innerHeight ); camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 10000); camera.position.z = 600; scene = new THREE.Scene(); var texture = THREE.ImageUtils.loadTexture( "land_ocean_ice_cloud_2048.jpg" ); sphere = new THREE.Mesh(new THREE.SphereGeometry(200, 100, 100), new THREE.MeshBasicMaterial( { map:texture } )); scene.add(sphere); // add lighting var light = new THREE.DirectionalLight(0xFFFFFF); light.position.x = 150; light.position.y = 250; light.position.z = 150; scene.add(light); // attach the scene to the DOM document.getElementById("container").appendChild(renderer.domElement); animate(); } function animate() { window.webkitRequestAnimationFrame(animate); renderer.render(scene, camera); }