Permalink
Cannot retrieve contributors at this time
Name already in use
A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
MobiusTransformsVisualizer/js/mobius.js
Go to fileThis commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
295 lines (228 sloc)
8.37 KB
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
var buffer; | |
var gl; | |
var canvas; | |
var glCanvas; | |
var program; | |
var tex; | |
function add_2d_ctrl(parent,variable,label,min_x,max_x,min_y,max_y) { | |
var container = document.createElement('div'); //Create the slider container | |
$(container).data('complex',variable) | |
container.id = label; | |
container.className ="slider-container"; | |
parent.append(container); | |
var slider = document.createElement('div');//Create the actual slider handle | |
slider.className = "sliderHandle"; | |
$(slider).draggable({ | |
containment: "parent", | |
//update value based on location, rounded to thrid decimal | |
drag: function(event, ui){//When it's dragged, call this function | |
variable.setVals(remap(ui.position.left,0,80,min_x,max_x),remap(ui.position.top,0,80,min_y,max_y)); | |
$(container).data('complex',variable) | |
imNum.nodeValue = 'im: ' +variable['im'].toFixed(3) | |
reNum.nodeValue = 're: ' +variable['re'].toFixed(3) | |
//method that updates current canvas | |
render(); | |
} | |
}); | |
slider.addEventListener("drag",function(){console.log('hello')}) | |
container.append(slider); | |
var caption = document.createElement('p'); | |
caption.className = "slider-caption"; | |
$(caption).text(label); | |
container.append(caption); | |
var value = document.createElement('div'); | |
var br = document.createElement('br'); | |
var imNum = document.createTextNode('im: '+variable['im']); | |
var reNum = document.createTextNode('re: '+variable['re']); | |
//value.id = label | |
value.append(imNum); | |
value.append(br) | |
value.append(reNum); | |
parent.append(value); | |
} | |
function add_vector_field(){ | |
canvas = document.createElement('canvas'); | |
canvas.style.border = "1px solid"; | |
canvas.id = 'canvas' | |
canvas.height = 500; | |
canvas.width = 500; | |
ctx = canvas.getContext('2d'); | |
document.body.appendChild(canvas); | |
height = canvas.height; | |
width = canvas.width; | |
} | |
//update based on id | |
function update_vector_field(a,b,c,d){ | |
ctx = canvas.getContext('2d'); | |
ctx.moveTo(0,0); | |
ctx.clearRect(0,0,600,600); | |
for(var i = 0;i<10;i++){ | |
for(var j = 0;j<10;j++){ | |
x = remap(i,0,10,-2,2); | |
y = remap(j,0,10,-2,2); | |
res = mobius(a,b,c,d,new Complex(x,y)); | |
pxx = remap(i,0,10,0,600); | |
pyy = remap(j,0,10,600,0); //flip y | |
rx = remap(res.re,-2,2,0,600); | |
ry = remap(res.im,-2,2,600,0); //flip y | |
ctx.beginPath(); | |
ctx.moveTo(pxx,pyy); | |
ctx.lineTo(rx,ry); | |
ctx.stroke(); | |
} | |
} | |
} | |
function render(a,b,c,d){ | |
a = $(document.getElementById('a')).data('complex'); | |
b = $(document.getElementById('b')).data('complex'); | |
c = $(document.getElementById('c')).data('complex'); | |
d = $(document.getElementById('d')).data('complex'); | |
update_vector_field(a,b,c,d); | |
} | |
function renderGL(texture) { | |
window.requestAnimationFrame(renderGL, canvas); | |
gl.clearColor(1.0, 0.0, 0.0, 1.0); | |
gl.clear(gl.COLOR_BUFFER_BIT); | |
positionLocation = gl.getAttribLocation(program, "a_position"); | |
gl.enableVertexAttribArray(positionLocation); | |
gl.vertexAttribPointer(positionLocation, 2, gl.FLOAT, false, 0, 0); | |
gl.uniform2f(gl.getUniformLocation(program, "a"),a.re,a.im); | |
gl.uniform2f(gl.getUniformLocation(program, "b"),b.re,b.im); | |
gl.uniform2f(gl.getUniformLocation(program, "c"),c.re,c.im); | |
gl.uniform2f(gl.getUniformLocation(program, "d"),d.re,d.im); | |
gl.drawArrays(gl.TRIANGLES, 0, 6); | |
} | |
//Load Texture function from MDN | |
function loadTexture(gl, url) { | |
const texture = gl.createTexture(); | |
gl.bindTexture(gl.TEXTURE_2D, texture); | |
// Because images have to be download over the internet | |
// they might take a moment until they are ready. | |
// Until then put a single pixel in the texture so we can | |
// use it immediately. When the image has finished downloading | |
// we'll update the texture with the contents of the image. | |
const level = 0; | |
const internalFormat = gl.RGBA; | |
const width = 1; | |
const height = 1; | |
const border = 0; | |
const srcFormat = gl.RGBA; | |
const srcType = gl.UNSIGNED_BYTE; | |
const pixel = new Uint8Array([0, 0, 255, 255]); // opaque blue | |
gl.texImage2D(gl.TEXTURE_2D, level, internalFormat, | |
width, height, border, srcFormat, srcType, | |
pixel); | |
const image = new Image(); | |
image.onload = function() { | |
gl.bindTexture(gl.TEXTURE_2D, texture); | |
gl.texImage2D(gl.TEXTURE_2D, level, internalFormat, | |
srcFormat, srcType, image); | |
// WebGL1 has different requirements for power of 2 images | |
// vs non power of 2 images so check if the image is a | |
// power of 2 in both dimensions. | |
if (isPowerOf2(image.width) && isPowerOf2(image.height)) { | |
// Yes, it's a power of 2. Generate mips. | |
gl.generateMipmap(gl.TEXTURE_2D); | |
} else { | |
// No, it's not a power of 2. Turn of mips and set | |
// wrapping to clamp to edge | |
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE); | |
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE); | |
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR); | |
} | |
}; | |
image.src = url; | |
return texture; | |
} | |
function isPowerOf2(value) { | |
return (value & (value - 1)) == 0; | |
} | |
var Complex = function(_re,_im){ | |
this.im = _im; | |
this.re = _re; | |
this.setVals = function(re,im){ | |
this.re = re; | |
this.im = im; | |
} | |
this.add = function(cpx){ | |
return new Complex(this.re+cpx.re,this.im+cpx.im) | |
}; | |
this.multiply = function(cpx){ | |
return new Complex(this.re*cpx.re - this.im*cpx.im,this.re*cpx.im + this.im*cpx.re); | |
}; | |
this.reciprocal = function(cpx){ | |
var _re = this.re / (this.re*this.re + this.im*this.im); | |
var _im = -this.im / (this.re*this.re + this.im*this.im); | |
return new Complex(_re,_im) | |
} | |
} | |
var mobius = function(a,b,c,d,z){ | |
return d.add(c.multiply(z)).reciprocal().multiply(b.add(a.multiply(z))); | |
} | |
var mobius_inv = function(a,b,c,d,z){ | |
return c.multiply(Complex(-1,0)).multiply(z).add(a).reciprocal().multiply(b.multiply(Complex(-1,0)).add(z.multiply(d))); | |
} | |
remap = function(x,a,b,c,d){ | |
//maps x from [a,b] to [c,d] | |
return (x - a) * (d - c) / (b - a) + c; | |
} | |
var a = new Complex(0,0); | |
var b = new Complex(0,0); | |
var c = new Complex(0,0); | |
var d = new Complex(0,0); | |
$(function () {//document is ready, setup everything | |
//Create GUI div | |
guibox = document.createElement('div'); | |
guibox.id = "gui-box"; | |
document.body.appendChild(guibox); | |
add_2d_ctrl($(guibox),a,"a",-1,1,-1,1); | |
add_2d_ctrl($(guibox),b,"b",-1,1,-1,1); | |
add_2d_ctrl($(guibox),c,"c",-1,1,-1,1); | |
add_2d_ctrl($(guibox),d,"d",-1,1,-1,1); | |
add_vector_field(); | |
glCanvas = document.createElement("canvas"); | |
glCanvas.id = 'glcanvas'; | |
glCanvas.width = 500; | |
glCanvas.height = 500; | |
document.body.appendChild(glCanvas); | |
gl = glCanvas.getContext('experimental-webgl'); | |
gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight); | |
buffer = gl.createBuffer(); | |
gl.bindBuffer(gl.ARRAY_BUFFER, buffer); | |
gl.bufferData( | |
gl.ARRAY_BUFFER, | |
new Float32Array([ | |
-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.STATIC_DRAW | |
); | |
tex = loadTexture(gl,"img/uvgrid.png"); | |
var shaderScript; | |
var shaderSource; | |
var vertexShader; | |
var fragmentShader; | |
shaderScript = document.getElementById("2d-vertex-shader"); | |
shaderSource = shaderScript.text; | |
vertexShader = gl.createShader(gl.VERTEX_SHADER); | |
gl.shaderSource(vertexShader, shaderSource); | |
gl.compileShader(vertexShader); | |
shaderScript = document.getElementById("2d-fragment-shader"); | |
shaderSource = shaderScript.text; | |
fragmentShader = gl.createShader(gl.FRAGMENT_SHADER); | |
gl.shaderSource(fragmentShader, shaderSource); | |
gl.compileShader(fragmentShader); | |
console.log(gl.getShaderInfoLog(fragmentShader)); | |
program = gl.createProgram(); | |
gl.attachShader(program, vertexShader); | |
gl.attachShader(program, fragmentShader); | |
gl.linkProgram(program); | |
gl.useProgram(program); | |
gl.activeTexture(gl.TEXTURE0); | |
gl.bindTexture(gl.TEXTURE_2D, tex); | |
gl.uniform1i(gl.getUniformLocation(program, 'sampler'), 0); | |
renderGL(program,tex); | |
}); |