Develop Reference

How to use shortened LUTs with javascript

based on this question
How to use LUT with JavaScript?
I tried to use this code
http://jsfiddle.net/gxu080ve/1/
var img = new Image,
canvas = document.getElementById("myCanvas"),
ctx = canvas.getContext("2d"),
src = "http://i.imgur.com/0vcCTK9.jpg?1"; // insert image url here
img.crossOrigin = "Anonymous";
img.onload = function() {
canvas.width = img.width;
canvas.height = img.height;
ctx.drawImage( img, 0, 0 );
// alternateImage(img, canvas, ctx);
localStorage.setItem( "savedImageData", canvas.toDataURL("image/png") );
loadNew();
}
img.src = src;
// make sure the load event fires for cached images too
if ( img.complete || img.complete === undefined ) {
img.src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==";
img.src = src;
}
var imgLut = new Image,
canvasLut = document.getElementById("myCanvasLut"),
ctxLut = canvasLut.getContext("2d"),
srcLut = "https://gm1.ggpht.com/nX2ZUYrMwPSXu5zGeeoMKyZP_R4nE205ivAdc3_yaccMEy8QYInfY_ynUB-NmrjvPKn0i1k7bdtHyk3Ul99ndvjvoCASud8FdIdq1fRrqDOCGK01rXgZZQ34ATKvtrkoysUCBmTUG70ZW_-TQxHExbu8gjhH-haIg0EuiWgJSxkL45jE1B4xWaOQNQXgJtmb7i1bSVcRgdmJq0XbttjsZnZn3YTW_LYw_3F-WyEEryTRritkZm6CW6NgaoVUfGH6XIaHp5Igs_dzm01lci9XwvoUwS0KA85w3npkjseL0zZX6u-pYWbSXOzkTLDJDMKPpOPt1VH6UUwARlD1YH1dQb0qdq4FrN8_beghJc00UaO9WHgyLyQ-NXMXFt5zXpeKuWtGwWtB0bzDhEvUXUhoDeOwaTbHlEjv3NgrqfzzpLBfLMM9J2BZLZodaEFA6WiroIsq70Qh6g_yMCVg02oi3s-L_2SSW2duayIIcfljyOxmC5AHbjzS2i-4RnKlVzK5Ge39wmiXX_4wtL0nb5XeDPwGbqqJsCPaeIYFN7z43HW6bA--5E3pUo3mjxLPTMSa8T-omZIw7w=w1896-h835-l75";
function loadNew(){
imgLut.crossOrigin = "Anonymous2";
imgLut.onload = function() {
canvasLut.width = imgLut.width;
canvasLut.height = imgLut.height;
ctxLut.drawImage( imgLut, 0, 0 );
filterImage(img, imgLut, canvasLut, ctxLut);
localStorage.setItem( "savedImageDataLut", canvasLut.toDataURL("image/png") );
}
imgLut.src = srcLutbyte;
// make sure the load event fires for cached images too
if ( imgLut.complete || imgLut.complete === undefined ) {
imgLut.src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==";
imgLut.src = srcLutbyte;
}
}
function alternateImage(img, canvastoapply, ctxToApply){
//var c=document.getElementById("myCanvas");
//var img=document.getElementById("scream");
ctxToApply.drawImage(img,0,0);
var imgData=ctxToApply.getImageData(0,0,canvastoapply.width,canvastoapply.height);
// invert colors
for (var i=0;i<imgData.data.length;i+=4){
imgData.data[i]=255-imgData.data[i];
imgData.data[i+1]=255-imgData.data[i+1];
imgData.data[i+2]=255-imgData.data[i+2];
imgData.data[i+3]=255;
}
ctxToApply.putImageData(imgData,0,0);
};
function filterImage(img, filter, canvastoapply, ctxToApply){
//var c=document.getElementById("myCanvas");
//var img=document.getElementById("scream");
// ctxToApply.drawImage(img,0,0);
var lutWidth = canvasLut.width;
var imgData=ctx.getImageData(0,0,canvas.width,canvas.height);
var filterData=ctxToApply.getImageData(0,0,canvastoapply.width,canvastoapply.height);
// invert colors
for (var i=0;i<imgData.data.length;i+=4){
var r=Math.floor(imgData.data[i]/4);
var g=Math.floor(imgData.data[i+1]/4);
var b=Math.floor(imgData.data[i+2]/4);
var a=255;
var lutX = (b % 8) * 64 + r;
var lutY = Math.floor(b / 8) * 64 + g;
var lutIndex = (lutY * lutWidth + lutX)*4;
var Rr = filterData.data[lutIndex];
var Gg = filterData.data[lutIndex+1];
var Bb = filterData.data[lutIndex+2];
imgData.data[i] = filterData.data[lutIndex];
imgData.data[i+1] = filterData.data[lutIndex+1];
imgData.data[i+2] = filterData.data[lutIndex+2];
imgData.data[i+3] = 255;
}
ctx.putImageData(imgData,0,0);
for the attached LUT and it does not work properly because it only has 5 colums instead of 8. Of course I read the comment from How to use LUT with JavaScript? which says "This code only applies for 64x64x64 3DLUT images. The parameters vary if your LUT has other dimensions; the / 4, * 64, % 8, / 8 must be changed for other dimensions, but in this question's scope the LUT is 64x64x64."
i tried to do so and only ended in a mess.
What would I please have to change to make it work?

Using PreloadJS to load images and adding them to CreateJS stage

I'm trying to create a Tri Peaks Solitaire game in Javascript, using CreateJS to help interact with the HTML canvas. I'm not entirely new to programming, as I've taken college courses on Java and C, but I am new to both Javascript and HTML.
I created a large amount of the card game using a Card class and Deck class, with the image adding, event listening, and game logic done in one Javascript file, but this resulted in a lot of messy, somewhat buggy code that I felt needed cleaning up.
I'm trying to implement a separate class for the card table, which will be the canvas, or stage, and it will draw the 4 rows of playable cards, the stock pile, and the waste pile. I'm currently just trying to get the stock pile to show up on the canvas, but it's not happening.
My question is, why is my stock pile not showing up? Also, as you can see, the card images are being loaded when the cards are created. Should I be doing that differently?
Card class:
var Card = function(number) {
this.isFaceUp = false;
//number for image file path
this.number = number;
this.value = Math.ceil( (this.number)/4 );
//back of the card is default image
this.initialize("images/" + 0 + ".png");
console.log("card created")
this.height = this.getBounds().height;
this.width = this.getBounds().width;
//load the card's front image
this.frontImage = new Image();
this.frontImage.src = ( this.getImagePath() );
};
Card.prototype = new createjs.Bitmap("images/" + this.number + ".png");
Card.prototype.getImagePath = function() {
return "images/" + this.number + ".png";
};
Card.prototype.getValue = function () {
return this.value;
}
Card.prototype.flip = function() {
// this.image = new Image();
// this.image.src = ( this.getImagePath() );
this.image = this.frontImage;
this.isFaceUp = true;
};
Card.prototype.getHeight = function() {
return this.height;
};
Card.prototype.getWidth = function() {
return this.width;
};
CardDeck class:
function CardDeck() {
//create empty array
this.deck = [];
//fill empty array
for(i=1; i<=52; i++) {
//fill deck with cards, with i being the number of the card
this.deck[i-1] = new Card(i);
}
//shuffle deck
this.shuffle();
}
CardDeck.prototype.getCard = function() {
if(this.deck.length < 1) alert("No cards in the deck");
return this.deck.pop();
};
CardDeck.prototype.getSize = function() {
return this.deck.length;
};
CardDeck.prototype.shuffle = function() {
for (i=0; i<this.deck.length; i++) {
var randomIndex = Math.floor( Math.random()*this.deck.length );
var temp = this.deck[i];
this.deck[i] = this.deck[randomIndex];
this.deck[randomIndex] = temp;
}
};
CardDeck.prototype.getRemainingCards = function() {
return this.deck.splice(0);
}
CardDeck.prototype.listCards = function() {
for(i=0; i<this.deck.length; i++) {
console.log(this.deck[i].number);
}
};
CardTable class:
var CardTable = function(canvas) {
this.initialize(canvas);
this.firstRow = [];
this.secondRow = [];
this.thirdRow = [];
this.fourthRow = [];
this.stockPile = [];
this.wastePile = [];
//startX is card width
this.startX = ( new Card(0) ).width*3;
//startY is half the card height
this.startY = ( new Card(0) ).height/2;
};
CardTable.prototype = new createjs.Stage();
CardTable.prototype.createStockPile = function(cards) {
for(i=0; i<23; i++) {
cards[i].x = 10;
cards[i].y = 50;
this.stockPile[i] = cards[i];
}
};
CardTable.prototype.addToWastePile = function(card) {
card.x = startX + card.width;
card.y = startY;
this.wastePile.push(card);
this.addChild(card);
this.update();
};
CardTable.prototype.drawStockPile = function() {
for(i=0; i<this.stockPile.length; i++) {
console.log("this.stockPile[i]");
this.addChild(this.stockPile[i]);
}
this.update();
};
HTML file:
<html>
<head>
<title>Tri-Peaks Solitaire</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<script src="https://code.createjs.com/easeljs-0.8.1.min.js"></script>
<script src="card.js"></script>
<script src="carddeck.js"></script>
<script src="cardtable.js"></script>
<script>
function init(){
var canvas = document.getElementById("canvas");
var table = new CardTable("canvas");
deck = new CardDeck();
table.createStockPile(deck.getRemainingCards());
table.drawStockPile();
table.update();
}
</script>
</head>
<body onload="init()">
<h1>Tri-Peaks Solitaire</h1>
<canvas style='border: 5px solid green; background: url("images/background.jpg");'
id="canvas" width="1000" height="450">
</canvas>
</body>
</html>
PRELOADJS UPDATE:
var canvas = document.getElementById("canvas");
var stage = new createjs.Stage(canvas);
var gameDeck = new CardDeck();
var numbers = [];
var preloader;
var progressText = new createjs.Text("", "20px Arial","#FF0000");
progressText.x = 50;
progressText.y = 20;
stage.addChild(progressText);
stage.update();
setupManifest();
startPreload();
function setupManifest() {
for(i=0; i<=52; i++) {
console.log("manifest");
manifest.push( {src:"images/" + i + ".png",
id: i} );
numbers.push(i);
}
}
function startPreload() {
preload = new createjs.LoadQueue(true);
preload.on("fileload", handleFileLoad);
preload.on("progress", handleFileProgress);
preload.on("complete", loadComplete);
preload.on("error", loadError);
preload.loadManifest(manifest);
}
function handleFileLoad(event) {
console.log("A file has loaded of type: " + event.item.type);
//console.log(numbers.pop());
var cardNumber = numbers.pop();
var newCard = new Card(cardNumber);
//faces.push( new Image() );
//faces[ faces.length - 1 ].src = "images/" + cardNumber + ".png";
gameDeck.insertCard(newCard);
}
function loadError(evt) {
console.log("error",evt.text);
}
function handleFileProgress(event) {
progressText.text = (preload.progress*100|0) + " % Loaded";
stage.update();
}
function loadComplete(event) {
console.log("Finished Loading Assets");
}

You are only updating the stage immediately after creating the cards. The cards are loading bitmap images, which is a concurrent operation that takes time. As such, the only time you render the stage is before the images load.
I would suggest using PreloadJS to preload your card images. This will also give you a lot more control over when / how they load, and let you show a progress bar or distractor to the user as they load.

I would suggest waiting for all the images to load and then calling stage.update(). Alternatively use the createjs.Ticker.addEventListener("tick", handleTick); event handler to update the stage for you.
Reference: http://www.createjs.com/docs/easeljs/classes/Ticker.html

Changes to Javascript created element doesn't reflect to DOM

I have a class, that is supposed to display grey overlay over page and display text and loading gif. Code looks like this:
function LoadingIcon(imgSrc) {
var elem_loader = document.createElement('div'),
elem_messageSpan = document.createElement('span'),
loaderVisible = false;
elem_loader.style.position = 'absolute';
elem_loader.style.left = '0';
elem_loader.style.top = '0';
elem_loader.style.width = '100%';
elem_loader.style.height = '100%';
elem_loader.style.backgroundColor = 'rgba(0, 0, 0, 0.5)';
elem_loader.style.textAlign = 'center';
elem_loader.appendChild(elem_messageSpan);
elem_loader.innerHTML += '<br><img src="' + imgSrc + '">';
elem_messageSpan.style.backgroundColor = '#f00';
this.start = function () {
document.body.appendChild(elem_loader);
loaderVisible = true;
};
this.stop = function() {
if (loaderVisible) {
document.body.removeChild(elem_loader);
loaderVisible = false;
}
};
this.setText = function(text) {
elem_messageSpan.innerHTML = text;
};
this.getElems = function() {
return [elem_loader, elem_messageSpan];
};
}
Problem is, when I use setText method, it sets innerHTML of elem_messageSpan, but it doesn't reflect to the span, that was appended to elem_loader. You can use getElems method to find out what both elements contains.
Where is the problem? Because I don't see single reason why this shouldn't work.
EDIT:
I call it like this:
var xml = new CwgParser('cwg.geog.cz/cwg.xml'),
loader = new LoadingIcon('./ajax-loader.gif');
xml.ondataparse = function() {
loader.stop();
document.getElementById('cover').style.display = 'block';
};
loader.setText('Loading CWG list...');
loader.start();
xml.loadXML();
xml.loadXML() is function that usually takes 3 - 8 seconds to execute (based on download speed of client), thats why I'm displaying loading icon.

Bind events to all elements in class instead of just to one id

I developed this interaction / script that scales whatever element is passed to it and if that element is pinched in on, it scales down / less.
This is how the script is initialised ( passing two arguments the container and the item to be scaled / transformed:
$(function(){
var zoom = new collapse('#zoom','#zoom :first');
var zoom2 = new collapse('#zoom2','#zoom2 :first');
var zoom3 = new collapse('#zoom3','#zoom3 :first');
});
It works fine as above on single IDs, but I need it to work on a class.
I tried this:
$(function(){
var zoom = new collapse('#zoom','.polaroid');
});
But that causes the whole script not to work because all the elements in that class are being passed instead of one as with an id.
This would only select the first item in the class so it won't work:
$(function(){
var zoom = new collapse('#zoom','.polaroid :first');
});
How can I change my script so that it is applied to all members of the .polaroid class in the #main container?
Here is my script:
function collapse(container, element){
container = $(container).hammer({
prevent_default: true,
scale_threshold: 0
});
element = $(element);
var displayWidth = container.width();
var displayHeight = container.height();
var MIN_ZOOM = 0;
var MAX_ZOOM = 1;
var scaleFactor = 1;
var previousScaleFactor = 1;
var startX = 0;
var startY = 0;
var translateX = 0;
var translateY = 0;
var previousTranslateX = 0;
var previousTranslateY = 0;
var time = 1;
var tch1 = 0,
tch2 = 0,
tcX = 0,
tcY = 0,
toX = 0,
toY = 0,
cssOrigin = "";
container.bind("transformstart", function(event){
e = event;
tch1 = [e.touches[0].x, e.touches[0].y],
tch2 = [e.touches[1].x, e.touches[1].y];
tcX = (tch1[0]+tch2[0])/2,
tcY = (tch1[1]+tch2[1])/2;
toX = tcX;
toY = tcY;
var left = $(element).offset().left;
var top = $(element).offset().top;
cssOrigin = (-(left) + toX)/scaleFactor +"px "+ (-(top) + toY)/scaleFactor +"px";
});
container.bind("transform", function(event){
scaleFactor = previousScaleFactor * event.scale;
scaleFactor = Math.max(MIN_ZOOM, Math.min(scaleFactor, MAX_ZOOM));
transform(event);
});
container.bind("transformend", function(event){
previousScaleFactor = scaleFactor;
if(scaleFactor > 0.42){
$(element).css('-webkit-transform', 'scaleY(1.0)').css('transform', 'scaleY(1.0)');
}
});
function transform(e){
var cssScale = "scaleY("+ scaleFactor +")";
element.css({
webkitTransform: cssScale,
webkitTransformOrigin: cssOrigin,
transform: cssScale,
transformOrigin: cssOrigin,
});
if(scaleFactor <= 0.42){
$(element).animate({height:0}, function(){
$(this).remove();
});
}
}
}

Wrap it as a jquery plugin:
$.fn.collapse = function(filter) {
return this.each(function(){
collapse(this,filter);
});
}
$("#zoom,#zoom1,#zoom2").collapse(".polaroid");
or if each of the zoom elements had a common class,
$(".zoomel").collapse(".polaroid");

You have to run collapse for each element.
element = $(element);
element.each(function(){
//each element would be this here
var $this= $(this);
//do whatever you want with $this
})

Resizing dynamic images not working more than one time

I've got a little problem here. I've been trying to do an image gallery with JavaScript but there's something that I got a problem with. I can get the image to resize when the first image load, but as soon as I load another image, it won't resize anymore! Since the user will be able to upload a lot of different size pictures, I really need to make it work.
I've checked for ready-to-use image gallery and such and nothing was doing what I need to do.
Here's my javascript:
function changeCurrentImage(conteneur)
{
var img = conteneur.getElementsByTagName("img");
var imgUrl = img[0].src;
var imgFirstPart = imgUrl.substring(0, imgUrl.lastIndexOf('.') - 9);
var imgLastPart = imgUrl.substring(imgUrl.lastIndexOf('.'));
var currentImg = document.getElementById('currentImage');
currentImg.src = imgFirstPart + "borne" + imgLastPart;
resize(document.getElementById('currentImage'), 375, 655);
}
function resize(img, maxh, maxw) {
var ratio = maxh/maxw;
if (img.height/img.width > ratio){
// height is the problem
if (img.height > maxh){
img.width = Math.round(img.width*(maxh/img.height));
img.height = maxh;
}
} else {
// width is the problem
if (img.width > maxw){
img.height = Math.round(img.height*(maxw/img.width));
img.width = maxw;
}
}
};
Here's the HTML (using ASP.Net Repeater):
<asp:Repeater ID="rptImages" runat="server">
<HeaderTemplate>
</HeaderTemplate>
<ItemTemplate>
<a href="#">
<div id="thumbnailImageContainer1" onclick="changeCurrentImage(this)">
<div id="thumbnailImageContainer2">
<img id="thumbnailImage" src="<%# SiteUrl + Eval("ImageThumbnailPath")%>?rn=<%=Random()%>" alt="Photo" onload="resize(this, 60, 105)" />
</div>
</div>
</a>
</ItemTemplate>
<FooterTemplate>
</FooterTemplate>
</asp:Repeater>

Most likely the image is not yet downloaded so img.height and img.width are not yet there. Technically you don't need to wait till the whole image is downloaded, you can poll the image in a timer until width and height are non-zero. This sounds messy but can be done nicely if you take the time to do it right. (I have an ImageLoader utility I made for this purpose....has only one timer even if it is handling multiple images at once, and calls a callback function when it has the sizes) I have to disagree with Marcel....client side works great for this sort of thing, and can work even if the images are from a source other than your server.
Edit: add ImageLoader utility:
var ImageLoader = {
maxChecks: 1000,
list: [],
intervalHandle : null,
loadImage : function (callback, url, userdata) {
var img = new Image ();
img.src = url;
if (img.width && img.height) {
callback (img.width, img.height, url, 0, userdata);
}
else {
var obj = {image: img, url: url, callback: callback,
checks: 1, userdata: userdata};
var i;
for (i=0; i < this.list.length; i++) {
if (this.list[i] == null)
break;
}
this.list[i] = obj;
if (!this.intervalHandle)
this.intervalHandle = setInterval(this.interval, 30);
}
},
// called by setInterval
interval : function () {
var count = 0;
var list = ImageLoader.list, item;
for (var i=0; i<list.length; i++) {
item = list[i];
if (item != null) {
if (item.image.width && item.image.height) {
item.callback (item.image.width, item.image.height,
item.url, item.checks, item.userdata);
ImageLoader.list[i] = null;
}
else if (item.checks > ImageLoader.maxChecks) {
item.callback (0, 0, item.url, item.checks, item.userdata);
ImageLoader.list[i] = null;
}
else {
count++;
item.checks++;
}
}
}
if (count == 0) {
ImageLoader.list = [];
clearInterval (ImageLoader.intervalHandle);
delete ImageLoader.intervalHandle;
}
}
};
Example usage:
var callback = function (width, height, url, checks, userdata) {
// show stuff in the title
document.title = "w: " + width + ", h:" + height +
", url:" + url + ", checks:" + checks + ", userdata: " + userdata;
var img = document.createElement("IMG");
img.src = url;
// size it to be 100 px wide, and the correct
// height for its aspect ratio
img.style.width = "100px";
img.style.height = ((height/width)*100) + "px";
document.body.appendChild (img);
};
ImageLoader.loadImage (callback,
"http://upload.wikimedia.org/wikipedia/commons/thumb/" +
"1/19/Caerulea3_crop.jpg/800px-Caerulea3_crop.jpg", 1);
ImageLoader.loadImage (callback,
"http://upload.wikimedia.org/wikipedia/commons/thumb/" +
"8/85/Calliphora_sp_Portrait.jpg/402px-Calliphora_sp_Portrait.jpg", 2);

With the way you have your code setup, I would try and call your resize function from an onload event.
function resize() {
var img = document.getElementById('currentImage');
var maxh = 375;
var maxw = 655;
var ratio = maxh/maxw;
if (img.height/img.width > ratio){
// height is the problem
if (img.height > maxh){
img.width = Math.round(img.width*(maxh/img.height));
img.height = maxh;
}
} else {
// width is the problem
if (img.width > maxw){
img.height = Math.round(img.height*(maxw/img.width));
img.width = maxw;
}
}
};
function changeCurrentImage(conteneur)
{
var img = conteneur.getElementsByTagName("img");
img.onload = resize;
var imgUrl = img[0].src;
var imgFirstPart = imgUrl.substring(0, imgUrl.lastIndexOf('.') - 9);
var imgLastPart = imgUrl.substring(imgUrl.lastIndexOf('.'));
var currentImg = document.getElementById('currentImage');
currentImg.src = imgFirstPart + "borne" + imgLastPart;
}
I would play around with that. Maybe use global variables for your maxH/W and image ID(s);

#Comments: No, I can't do that server side since it would refresh the page everytime someone click on a new image. That would be way too bothersome and annoying for the users.
As for the thumbnails, those image are already saved in the appropriate size. Only the big image that shows is about 33% of its size. Since we already have 3 images PER uploaded images, I didn't want to upload a 4th one for each upload, that would take too much server space!
As for the "currentImage", I forgot to add it, so that might be helful lol:
<div id="currentImageContainer">
<div id="currentImageContainer1">
<div id="currentImageContainer2">
<img id="currentImage" src="#" alt="" onload="resize(this, 375, 655)" />
</div>
</div>
</div>
#rob: I'll try the ImageLoader class, that might do the trick.

I found an alternative that is working really well. Instead of changing that IMG width and height, I delete it and create a new one:
function changeCurrentImage(conteneur)
{
var thumbnailImg = conteneur.getElementsByTagName("img");
var thumbnailImgUrl = thumbnailImg[0].src;
var newImgUrl = thumbnailImgUrl.replace("thumbnail", "borne");
var currentImgDiv = document.getElementById('currentImageContainer2');
var currentImg = currentImgDiv.getElementById("currentImage");
if (currentImg != null)
{
currentImgDiv.removeChild(currentImg);
}
var newImg = document.createElement("img");
newImageDiv = document.getElementById('currentImageContainer2');
newImg.id = "currentImage";
newImg.onload = function() {
Resize(newImg, 375, 655);
newImageDiv.appendChild(newImg);
}
newImg.src = newImgUrl;
}
Also, in case people wonder, you MUST put the .onload before the .src when assigning an a new source for an image!