thebookofshaders/src/main.js
2017-08-23 11:34:44 +02:00

290 lines
8.0 KiB
JavaScript

// PARSING
//---------------------------------------------------------------
// Graph plotter function take from
// From http://blog.hvidtfeldts.net/index.php/2011/07/plotting-high-frequency-functions-using-a-gpu/
var preFunction = "\n\
#ifdef GL_ES\n\
precision mediump float;\n\
#endif\n\
\n\
#define PI 3.14159265359\n\
\n\
uniform vec2 u_resolution;\n\
uniform vec2 u_mouse;\n\
uniform float u_time;\n\
\n\
float lineJitter = 0.5;\n\
float lineWidth = 7.0;\n\
float gridWidth = 1.7;\n\
float scale = 0.0013;\n\
float zoom = 2.5;\n\
vec2 offset = vec2(0.5);\n\
\n\
float rand (in float _x) {\n\
return fract(sin(_x)*1e4);\n\
}\n\
\n\
float rand (in vec2 co) {\n\
return fract(sin(dot(co.xy,vec2(12.9898,78.233)))*43758.5453);\n\
}\n\
\n\
float noise (in float _x) {\n\
float i = floor(_x);\n\
float f = fract(_x);\n\
float u = f * f * (3.0 - 2.0 * f);\n\
return mix(rand(i), rand(i + 1.0), u);\n\
}\n\
\n\
float noise (in vec2 _st) {\n\
vec2 i = floor(_st);\n\
vec2 f = fract(_st);\n\
// Four corners in 2D of a tile\n\
float a = rand(i);\n\
float b = rand(i + vec2(1.0, 0.0));\n\
float c = rand(i + vec2(0.0, 1.0));\n\
float d = rand(i + vec2(1.0, 1.0));\n\
vec2 u = f * f * (3.0 - 2.0 * f);\n\
return mix(a, b, u.x) + \n\
(c - a)* u.y * (1.0 - u.x) + \n\
(d - b) * u.x * u.y;\n\
}\n\
\n\
float function(in float x) {\n\
float y = 0.0;\n";
var postFunction = "\n\
return y;\n\
}\n\
\n\
vec3 plot2D(in vec2 _st, in float _width ) {\n\
const float samples = 3.0;\n\
\n\
vec2 steping = _width*vec2(scale)/samples;\n\
\n\
float count = 0.0;\n\
float mySamples = 0.0;\n\
for (float i = 0.0; i < samples; i++) {\n\
for (float j = 0.0;j < samples; j++) {\n\
if (i*i+j*j>samples*samples) \n\
continue;\n\
mySamples++;\n\
float ii = i + lineJitter*rand(vec2(_st.x+ i*steping.x,_st.y+ j*steping.y));\n\
float jj = j + lineJitter*rand(vec2(_st.y + i*steping.x,_st.x+ j*steping.y));\n\
float f = function(_st.x+ ii*steping.x)-(_st.y+ jj*steping.y);\n\
count += (f>0.) ? 1.0 : -1.0;\n\
}\n\
}\n\
vec3 color = vec3(1.0);\n\
if (abs(count)!=mySamples)\n\
color = vec3(abs(float(count))/float(mySamples));\n\
return color;\n\
}\n\
\n\
vec3 grid2D( in vec2 _st, in float _width ) {\n\
float axisDetail = _width*scale;\n\
if (abs(_st.x)<axisDetail || abs(_st.y)<axisDetail) \n\
return 1.0-vec3(0.65,0.65,1.0);\n\
if (abs(mod(_st.x,1.0))<axisDetail || abs(mod(_st.y,1.0))<axisDetail) \n\
return 1.0-vec3(0.80,0.80,1.0);\n\
if (abs(mod(_st.x,0.25))<axisDetail || abs(mod(_st.y,0.25))<axisDetail) \n\
return 1.0-vec3(0.95,0.95,1.0);\n\
return vec3(0.0);\n\
}\n\
\n\
void main(){\n\
vec2 st = (gl_FragCoord.xy/u_resolution.xy)-offset;\n\
st.x *= u_resolution.x/u_resolution.y;\n\
\n\
scale *= zoom;\n\
st *= zoom;\n\
\n\
vec3 color = plot2D(st,lineWidth);\n\
color -= grid2D(st,gridWidth);\n\
\n\
gl_FragColor = vec4(color,1.0);\n\
}";
var glslCanvas = [];
var glslEditors = [];
var glslGraphs = [];
function styleCodeBlocks() {
// Highlight code blocks
var list = document.getElementsByTagName("code");
for(var i = 0; i < list.length; i++){
if (list[i].className == "language-glsl" ||
list[i].className == "language-bash" ||
list[i].className == "language-cpp" ||
list[i].className == "language-html" ||
list[i].className == "language-processing" ){
hljs.highlightBlock(list[i]);
}
}
}
function loadGlslElements() {
// Load single Shaders
var canvas = document.getElementsByClassName("canvas");
for (var i = 0; i < canvas.length; i++){
glslCanvas.push(new GlslCanvas(canvas[i]));
}
// parse EDITORS
var ccList = document.querySelectorAll(".codeAndCanvas");
for(var i = 0; i < ccList.length; i++){
if (ccList[i].hasAttribute("data")){
var srcFile = ccList[i].getAttribute("data");
var editor = new GlslEditor(ccList[i], {
canvas_size: 250,
canvas_follow: true,
canvas_float: 'right',
tooltips: true,
exportIcon: true
});
editor.open(srcFile);
glslEditors.push(editor);
}
}
// parse GRAPHS
var sfList = document.querySelectorAll(".simpleFunction");
for(var i = 0; i < sfList.length; i++){
if (sfList[i].hasAttribute("data")){
var srcFile = sfList[i].getAttribute("data");
glslGraphs.push(new GlslEditor(sfList[i], {
canvas_width: 800,
lineNumbers: false,
canvas_height: 250,
canvas_follow: true,
canvas_float: false,
frag_header: preFunction,
frag_footer: postFunction,
tooltips: true
}).open(srcFile));
}
}
}
function insertAfter(newElement,targetElement) {
var parent = targetElement.parentNode;
if (parent.lastChild == targetElement) {
parent.appendChild(newElement);
} else {
parent.insertBefore(newElement,targetElement.nextSibling);
}
}
function captionizeImages() {
if (!document.getElementsByTagName)
return false;
if (!document.createElement)
return false;
var images = document.getElementsByTagName("img");
if (images.length < 1)
return false;
for (var i = 0; i < images.length; i++) {
var title = images[i].getAttribute("alt");
if (title && title !== ''){
var divCaption = document.createElement("div");
divCaption.className = "caption";
var divCaption_text = document.createTextNode(title);
divCaption.appendChild(divCaption_text);
var divContainer = document.createElement("div");
divContainer.className="imgcontainer";
images[i].parentNode.insertBefore(divContainer,images[i]);
divContainer.appendChild(images[i]);
insertAfter(divCaption,images[i]);
}
}
}
// NAVIGATION
//-----------------------------------------------------------------------
function FormatNumberLength(num, length) {
var r = "" + num;
while (r.length < length) {
r = "0" + r;
}
return r;
}
function checkUrl(url) {
var request = false;
if (window.XMLHttpRequest) {
request = new XMLHttpRequest;
} else if (window.ActiveXObject) {
request = new ActiveXObject("Microsoft.XMLHttp");
}
if (request) {
request.open("GET", url);
if (request.status == 200) { return true; }
}
return false;
}
function getParameterByName(name) {
name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
results = regex.exec(location.search);
return results === null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
}
function previusPage() {
var path = window.location.pathname;
var n = parseInt( path.match( /[0-1].(?!.*[0-1])/ )[0] );
var url;
n -= 1;
if(n < 0){
url = "../";
} else {
url = "../" + FormatNumberLength(n,2) + "/";
}
var language = getParameterByName('lan');
if (language !== ""){
url += "?lan="+language;
}
window.location.href = url;
}
function homePage() {
window.location.href = "../";
}
function nextPage() {
var path = window.location.pathname;
var n = parseInt( path.match( /[0-1].(?!.*[0-1])/ )[0] );
n += 1;
var url = "../" + FormatNumberLength(n,2) + "/";
var language = getParameterByName('lan');
if (language !== ""){
url += "?lan="+language;
}
window.location.href = url;
}
window.addEventListener("load", function(){
window.scrollTo(0, 0);
styleCodeBlocks();
loadGlslElements();
captionizeImages();
window.scrollTo(0, 0);
setTimeout(function () {
window.scrollTo(0, 0);
}, 500);
});