< script src = lib2.js > < / script >
< script src = "https://cdnjs.cloudflare.com/ajax/libs/ace/1.4.12/ace.js" crossorigin = "anonymous" > < / script >
< script src = "https://cdnjs.cloudflare.com/ajax/libs/ace/1.4.12/ext-language_tools.js" crossorigin = "anonymous" > < / script >
< style >
.ace_gutter-layer {
/* original width is 48px */
width: 25px !important;
}
.ace_gutter-layer > * {
/* 48 - 32 = 16 */
margin-left: 0;
}
.ace_gutter-cell {
padding-left: 0 !important;
padding-right: 3px !important;
}
.code{
font-family: "monaco, menlo, ubuntu mono, consolas, source-code-pro" ;
}
< / style >
< body bgcolor = white text = black link = black alink = blue vlink = blue >
< center >
< canvas id = 'canvas1' width = 600 height = 600 > < / canvas >
< / center >
< / body >
<!!-------- VERTEX SHADER: YOU PROBABLY DON'T WANT TO CHANGE THIS RIGHT NOW -------->
< script id = 'my_vertex_shader' type = 'x-shader/x-vertex' >
attribute vec3 aPos;
varying vec3 vPos;
void main() {
gl_Position = vec4(aPos, 1.);
vPos = aPos;
}
< / script >
<!!-------- FRAGMENT SHADER: THIS IS WHERE YOU WILL DO YOUR WORK -------->
< script src = "shader.frag" id = 'my_fragment_shader' type = 'x-shader/x-fragment' > < / script >
<!!-------- CREATE A PROPERLY DESCRIPTIVE TITLE BELOW -------->
< script id = 'my_title' type = 'text/html' >
The Bouncing Earth
< / script >
<!!-------- HERE IS WHERE YOU CAN PROVIDE A LONGER TEXT DESCRIPTION -------->
< script id = 'my_instructions' type = 'text/html' > < f o n t c o l o r = # 9 0 9 0 9 0 >
< p style = "font-size:30px; " > This is a description
of my cool homework
that you are seeing now.< / p >
< p >
< i style = "font-size:25px;" > Here is how it works:< / i >
< ul >
< li > First, I added < a href = "http://planetpixelemporium.com/download/download.php?earthmap1k.jpg" > texture< / a > to the sphere. The code to load the texture is from
< a href = "https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/Tutorial/Using_textures_in_WebGL" > here< / a > . Please wait a sec for the texture to download.< / li >
< li > Then, I mapped the 3D sphere surface to the rectangular 2D texture picture. < / li >
< li > I also make it look like it's rotating by adding uTime to the offset of the texture and reset the offset to 0 whenever it exceeds
the width of the texture.< / li >
< li > I used Perlin Noise to generate fake clouds.< / li >
< li > I modified the lighting so that the light source won't move with the sphere and
the lighting will change when the sphere moves. I also added specular lights to make it shinier.< / li >
< li > I tried to add some 'soft shadow' to it. I used a mix of methods inspired by Ambient Occlusion and Ray Tracing.< br >
< ul >
< li > The Ambient lights and diffusion lights are reduced with respect to the distance between the background point and the sphere.< / li >
< li > The specular light of the background wall is eliminated and the diffusion factor is reduced when the ray shooting from the background point
towards the light source or from the background point towards the camera position intersect with the sphere.< / li >
< / ul >
< li > I added basic interactions such as press ctrl + 't' key to hide/show texture, click on the above canvas to pause/unpause animations.
Just a proof of concept.< / li >
< li > Finally, I made some small changes like changing R over time and refined the UI a little bit. I used
< a href = "https://ace.c9.io" > Ace< / a > for code highlighting and autocompletion on the edit panel.< / li >
< li > Comments begin with '//*' are added by me.< / li >
< li > Repo on < a href = "https://github.com/sunyinqi0508/graphics_hw1" > Github< / a > .< / li >
< / li >
< / ul >
< p >
< / script >
<!!-------- YOU PROBABLY DON'T WANT TO CHANGE ANYTHING BELOW FOR NOW -------->
< script >
// CREATE THE HTML DOCUMENT
let flags = 0x0;
let vs = my_vertex_shader.innerHTML;
var client = new XMLHttpRequest();
client.open('GET', './shader.frag');
client.onloadend = function() {
fs = (client.responseText);
// START EVERYTHING.
gl_start(canvas1, vs, fs);
editor.getSession().setValue(fs);
editor.session.on('change', function(delta) {
if(typeof canvas1.setShaders === "function")
{
canvas1.setShaders(vs, editor.getSession().getValue());
setUniform('1i', 'flags', flags);
}
});
}
client.send();
document.body.innerHTML = [''
,'< font size = 7 color = #909090 > ' + my_title.innerHTML
,'< TABLE cellspacing = 0 cellpadding = 0 > < TR > '
,'< td > < font color = red size = 5 > < div id = errorMessage > < / div > < / font > < / td > '
,'< / TR > < TR > '
,'< table cellspacing = 0 > '
,'< tr > '
,'< td valign = top > '
,'< div id = "ace" style = "width:800px;height:1780px;" > < / div > '
,'< / td > < td valign = top > ' + document.body.innerHTML + '< div style = \'font-size:25px\' > ' + my_instructions.innerHTML + '< / div > ' + '< / td > '
,'< / tr > < / table > '
,'< / TR > < / TABLE > '
].join('');
// SET UP THE EDITABLE TEXT AREA ON THE LEFT SIDE.
ace.require("ace/ext/language_tools");
var editor = ace.edit("ace", {
mode:"ace/mode/glsl",
theme:"ace/theme/crimson_editor"
});
editor.setOptions({
enableBasicAutocompletion: true,
enableSnippets: true,
enableLiveAutocompletion: true,
fontSize: 14,
fontFamily: "monaco, menlo, ubuntu mono, consolas, source-code-pro",
fixedWidthGutter: true,
showGutter: true,
showPrintMargin: false,
});
editor.setAutoScrollEditorIntoView(true);
// REPARSE THE SHADER PROGRAM AFTER EVERY KEYSTROKE.
let lastTime = Date.now();
let animating = true;
let ctrl = false;
canvas1.addEventListener('click',function(ev){
if(animating)
lastTime = Date.now();
else
startTime += Date.now() - lastTime;
animating = !animating;
});
document.addEventListener('keydown',(e)=>{
if(e.code.startsWith('Control'))
{
ctrl = true;
}
else if(ctrl & & e.code == 'KeyT')
{
mask = 0x1;
flags = flags& !mask | (!(flags&mask)?mask:0);
setUniform('1i', 'flags', flags);
}
else if (ctrl & & e.code == 'KeyS')
{
let a = document.createElement('a');
a.href = "data:text/plain,"+encodeURIComponent(editor.getSession().getValue());
a.download = 'shader.frag';
a.click();
}
});
document.addEventListener('keyup',(e)=>{
if(e.code.startsWith('Control'))
{
ctrl = false;
}
});
// SET THE CURRENT TIME IN SECONDS BEFORE RENDERING EACH FRAME.
let startTime = Date.now();
function animate(gl) {
if(animating)
setUniform('1f', 'uTime', (Date.now() - startTime) / 1000);
else
setUniform('1f', 'uTime', (lastTime - startTime) / 1000);
}
< / script >
