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Overlapping image inside a table

Question: how 2 images can live in the same td ? how can I overlap the first one?
Bug: the images doesn't overlapping, sometimes the character's image is printed next to the tiles images instead to overlap it.
I will link to you the pen of this little program, try to random generate different times to occur in this bug.
penHere
After the first sections of customization a random map will generate the position of the characters.
I investigate over this bug, and i discover that it's not a problem of coordinates ( they are random generated with this function )
function coordinate(){
let rowCoord= map.length;
let cellCoord = map[1].length;
let coord = {
row: Math.floor(Math.random() * rowCoord),
cell: Math.floor(Math.random() * cellCoord)
}
return coord;
};
// this function will place the character if the coordinates are ok. Else we have a callback to the same function.
function placeCharAndItem(char){
let coord = coordinate();
// with this if you choose a walkable table to spawn, this is random generated
if(map[coord.row][coord.cell] === 0 ){
place(coord, char);
}
else{
placeCharAndItem(char);
}
};
The map is random generated too. It's something like this.
map = [[1,1,1,1,0],
[1,0,0,0,0],
[1,0,1,1,1],
[1,0,0,0,1],
[1,1,1,0,1]]
and this is the function that let the character image spawn on the right td
function place(coord, char){
var charImage = $("<img>").attr("src", char.image).addClass('char');
var row = $($("#tableGame tr")[coord.row]);
var cell = $($("td", row)[coord.cell]);
cell.append(charImage);
};
Thanks :)

If you just put two images in a table cell, they will be displayed one after the other by default, this is just how the HTML works.
To make overlap of two images you can explicitly set position of the second image relative to it's parent table cell. You can do it with CSS:
Apply position: relative; to the parent td;
Apply:
position: absolute;
top: 0;
left: 0;
to the second image (and all next images in the same cell, if you will have more).
Keep in mind that second image now will be out of the standard HTML flow, it will no longer affect the cell size, it will overlap anything. You may need to explicitly set the cell size.
Also you can set this styles dynamically with the JQuery:
// Get your table cell and image somehow.
const $cell = $(...);
const $image = $(...);
$cell.css('position', 'relative');
$image.css({
position: 'absolute',
top: 0,
left: 0,
});
Or with a plain JS:
const cell = document.querySelector(...);
const image = document.querySelector(...);
cell.style.position = 'relative';
image.style.position = 'absolute';
image.style.top = 0;
image.style.left = 0;

'Media-queries' for javascript - different code for different viewport height/widths

The problem
I'm using javascript to calculate widths of elements to achieve the layout I'm after. The problem is, I don't want to load the code on smaller screen sizes (when the screen width is less than 480px for example). I'd like this to work on load and on browser/viewport resize.
I'd consider small screen devices 'the default' and working up from there. So, none of the following script is called by default, then if the browser width is greater than 480px (for example), the following script would be called:
The code
$(document).ready(function() {
//Get the figures width
var figure_width = $(".project-index figure").css("width").replace("px", "");
//Get num figures
var num_figures = $(".project-index figure").length;
//Work out how manay figures per row
var num_row_figures = Math.ceil(num_figures / 2);
//Get the total width
var row_width = figure_width * num_row_figures;
//Set container width to half the total
$(".project-index").width(row_width);
x = null;
y = null;
$(".project-index div").mousedown(function(e) {
x = e.clientX;
y = e.clientY;
});
$(".project-index div").mouseup(function(e) {
if (x == e.clientX && y == e.clientY) {
//alert($(this).next().attr("href"));
window.location.assign($(this).next().attr("href"));
}
x = y = null;
});
});
// Drag-on content
jQuery(document).ready(function() {
jQuery('#main').dragOn();
});
The extra bit
The slight difference on larger screens is to do with the browser/viewport height. This is in regards to the line:
var num_row_figures = Math.ceil(num_figures / 2);
You can see once the calculation has a value, it divides it by 2. I only want this to happen when the browser/viewport height is above a certain amount - say 600px.
I'd be happy with this being the 1st state and then the value is divided by 2 if the height is greater than 600px if it's easier.
Can anyone help me/shed some light on how to manage my script this way. I know there's media queries for managing CSS but I can't seem to find any resources for how to manage javascript this way - hope someone can help.
Cheers,
Steve

You can use window.matchMedia, which is the javascript equivalent of media queries. The matchMedia call creates a mediaQueryList object. We can query the mediaQueryList object matches property to get the state, and attach an event handler using mediaQueryList.addListener to track changes.
I've added an example on fiddle of using matchMedia on load and on resize. Change the bottom left pane height and width (using the borders), and see the states of the two queries.
This is the code I've used:
<div>Min width 400: <span id="minWidth400"></span></div>
<div>Min height 600: <span id="minHeight600"></span></div>
var matchMinWidth400 = window.matchMedia("(min-width: 400px)"); // create a MediaQueryList
var matchMinHeight600 = window.matchMedia("(min-height: 600px)"); // create a MediaQueryList
var minWidth400Status = document.getElementById('minWidth400');
var minHeight600Status = document.getElementById('minHeight600');
function updateMinWidth400(state) {
minWidth400Status.innerText = state;
}
function updateMinHeight600(state) {
minHeight600Status.innerText = state;
}
updateMinWidth400(matchMinWidth400.matches); // check match on load
updateMinHeight600(matchMinHeight600.matches); // check match on load
matchMinWidth400.addListener(function(MediaQueryListEvent) { // check match on resize
updateMinWidth400(MediaQueryListEvent.matches);
});
matchMinHeight600.addListener(function(MediaQueryListEvent) { // check match on resize
updateMinHeight600(MediaQueryListEvent.matches);
});

#media screen and (max-width: 300px) {
body {
background-color: lightblue;
}
}
So i searched a bit and came up with this example from w3 schools .http://www.w3schools.com/cssref/tryit.asp?filename=trycss3_media_example1
i think this is something you are trying to achieve.
For pure js , you can get the screen width by screen.width

Programmatically Resizing Divs

I'm working on an HTML5 browser game that can be divided into 3 parts: two UI panels on the left and right of a center set of square canvases for the playing surface. The three panels need to be horizontally aligned, and the total game needs to keep an aspect ratio of 16:9. The left and right panels should be of equal widths, and all three panels must be of equal height. I have specified a minimum width and height inside a resize() function called when an onresize event is detected.
Currently, each panel is a div, and all three are contained inside a section. Right now, the section isn't necessary, but I want to keep the game separated from extra content at the bottom of the screen that I might choose to add later.
The CSS style is as follows:
* {
vertical-align: baseline;
font-weight: inherit;
font-family: inherit;
font-style: inherit;
font-size: 100%;
border: 0 none;
outline: 0;
padding: 0;
margin: 0;
}
#gameSection {
white-space: nowrap;
overflow-x: hide;
overflow-y: hide;
}
#leftPanel, #centerPanel, #rightPanel {
display: inline-block;
}
#leftPanel {
background-color: #6495ed;
}
#centerPanel {
background-color: #e0ffff;
}
#rightPanel {
background-color: #b0c4de;
Right now, I have set the background color of each div just to show me when I'm correctly setting the size of each div.
The body of my HTML document is as follows:
<body onresize="resize()">
<section id="gameSection">
<div id="leftPanel">Left Panel.</div>
<div id="centerPanel">Center Panel.</div>
<div id="rightPanel">Right Panel.</div>
</section>
</body>
And finally, my resize() function (I created a separate function for resizing the game in case I add more elements below later):
function resize() {
var MIN_GAME_WIDTH = 800;
var MIN_GAME_HEIGHT = 450;
var GAME_ASPECT_RATIO = 16 / 9;
var width = window.innerWidth;
var height = window.innerHeight;
var gWidth, gHeight;
if(width < MIN_GAME_WIDTH || height < MIN_GAME_HEIGHT) {
gWidth = MIN_GAME_WIDTH;
gHeight = MIN_GAME_HEIGHT;
}
else if ((width / height) > GAME_ASPECT_RATIO) {
<!-- width is too large for height -->
gHeight = height;
gWidth = height * GAME_ASPECT_RATIO;
}
else {
<!-- height is too large for width -->
gWidth = width;
gHeight = width / GAME_ASPECT_RATIO;
}
resizeGame(gWidth, gHeight, GAME_ASPECT_RATIO);
}
function resizeGame(var gWidth, var gHeight, var aspectRatio) {
var gSection = document.getElementById("gameSection");
var lPanel = document.getElementById("leftPanel");
var cPanel = document.getElementById("centerPanel");
var rPanel = document.getElementById("rightPanel");
gSection.height = gHeight;
gSection.width = gWidth;
<!-- should the below be taken care of in the CSS? -->
lPanel.height = gHeight;
cPanel.height = gHeight;
rPanel.height = gHeight;
cPanel.width = cPanel.height;
lPanel.width = (gWidth - cPanel.width) / 2;
rPanel.width = lPanel.width;
}
I've tried a number of different commands to resize the divs, but it just isn't working for me. When I try adding test canvases, color appears, but the boxes still aren't the correct size. I have also considered loading an invisible background image to each div and scaling it to the desired size; however, I was able to resize my canvas using the above method before and it seemed to work just fine.
Additional Notes
While I've already had pretty good success resizing a single canvas, I don't want to use just one canvas for the game because not all parts of the UI need to be drawn at the same time.
I'm trying to keep this solely in Javascript.
I suspect that I could just use CSS to handle resizing by fixing the aspect ratio to 16:9 and using width:56.25% for the center panel and width:21.875% for the side panels, but that limits me to one aspect ratio and doesn't explain why my above script isn't working.
I can provide the entire HTML file if needed. This is what it's supposed to look like:
End Goal (without right panel)
Thank you!
UDPATE:
jsfiddle

I got it kind of working here. I made a lot of changes/minor fixes to the code before finding what was wrong (other than various syntax errors):
You were using .width and .height instead of .style.width and .style.height, and you were applying integers to these instead of strings with "px" appended to them. Both of these things are completely understandable to miss.
I also moved the onresize from the body tag into the JS, don't know why it wasn't working on jsfiddle, but this is good practice anyways.
In the future: learn how to debug JS using the console and when you ask questions, use small examples, not your entire codebase. This question could have been simplified to "How do I resize a div?" with one line of JS and one div. You also should consider not doing this specific thing in JS, and using flexbox as redbmk said.

jQuery.clone() an element, then add dynamic styling to it

Let's say I have an image, cat.jpg, and when clicked I want to clone it.
$('img.cat').on("click", function() {
$(this).clone().appendTo('#container');
});
Upon duplication, however, I want the new cat.jpg to appear as half the size of the original. And I want this to continue happening each time a new cat.jpg is clicked.
Any ideas on how to go about accomplishing this? Is it even possible to inject new styling/classes/parameters via .clone()?

It sounds like the following is what you're after:
// If all images are within #container, use $("#container") instead:
$(document).on("click", "img.cat", function () {
var original = $(this);
original.clone().css({
width: original.width() / 2,
height: original.height() / 2
}).appendTo("#container");
});
Fiddle: http://jsfiddle.net/G6XTz/
Of course, you may have wanted the newly added image to be half the size of the last cat image, rather than the cat image clicked:
Fiddle2: http://jsfiddle.net/G6XTz/1/
Caveat:
The width and height can only divide so far; eventually you'll run into some problems. Better check the result of division first, and make a decision to do something else when it makes sense.

Just setting the width to half seems to be enough with an img element, the height gets set automatically in proportion to the width:
$('#container').on('click','img.cat', function() {
$(this).clone()
.appendTo('#container')
.width(function(i,v) { return v/2;});
});
Demo: http://jsfiddle.net/Mr2x8/
But if you find you need to set the width and the height here's one way to do it:
$('#container').on('click','img.cat', function() {
var $this = $(this);
$this.clone()
.appendTo('#container')
.width($this.width()/2)
.height($this.height()/2);
});
Demo: http://jsfiddle.net/Mr2x8/1/

id do this:
$(this).clone().addClass('small').appendTo('#container');
this adds the css class small to the clone of this.

Create a new class with the specific new styling you want to get changed dynamicaly in your CSS file.
.newClass {
//example green outline
outline: solid thin green;
}
And then modify your script:
$('img.cat').on("click", function() {
$(this).clone().addClass('newClass').appendTo('#container');
});
EDIT :
If the only thing you want to change is the size of the img for lets say 10% each click then:
$('img.cat').on("click", function() {
var width = $(this).width() * 0.9;
var height = $(this).height() * 0.9;
$(this).clone().css({"width":width+"px", "height":height+"px"}).appendTo('#container');
});
The above code will produce the same image but 10% smaller than the image clicked .
If you want to click only the initial image then simply put the width and height variable outside the click function and update them inside for each click.
NOTE :
In the css() you add +"px" if initial width is in px else you add +"%" if it is in percentage.

White space on right of page

How do I get rid of that undesired white border on the right of the page?
The website basically dynamically resizes images on a grid, here's a video: https://vine.co/v/h2wtnw6K3H0
CSS:
body {
height: 100%;
width: 100%;
margin: 0;
}
grid {
height: 100%;
width: 100%;
}
.gridImage {
vertical-align: bottom;
margin-left: 0px;
margin-right: 0px;
margin-top: 0px;
margin-bottom: 0px;
}
JS:
function resize() {
console.log($(window).width());
var newBody = "";
for (var i = 0; i <= 100; i++) {
newBody += '<img class="gridImage" src="Images/image2.jpg" width="' + $(window).width() / Math.floor(($(window).width() / 100)) + 'px" height="' + $(window).width() / Math.floor(($(window).width() / 100)) + 'px">';
}
document.getElementById("grid").innerHTML = newBody;
}
If my margins are zero, why is this showing up? Anything I'm missing? Thanks.

Ridcully has covered what the problem is, but here’s a solution.
First you would need to calculate the desired width of each image. This is simply your current equation wrapped in Math.ceil().
var windowWidth = $(window).width() // A slight performance improvement, plus cleaner code
var maxImageWidth = <your value here>
var unroundedImageWidth = windowWidth / Math.floor(windowWidth / maxImageWidth)
var roundedImageWidth = Math.ceil(unroundedImageWidth)
Unless your images fit perfectly, this will make each row slightly wider than the window, causing the final image on each line to wrap to the next. To prevent this, you need to set the gridContainer’s width to that of each row.
$('.gridContainer').width(windowWidth * roundedImageWidth / unroundedImageWidth)
Everything should look good, except for one thing: the horizontal scrollbar. This is easily fixed, however. Add this to your CSS:
.gridContainer {
overflow-x: hidden;
}
This will hide both the scrollbar and the final few pixels on each line. Perfect! Well, not quite.
The problem with this method is that one image per row takes the hit (loses pixels) for all of the others. If you have small images and a lot of images per row, you could end up losing a significant portion of your final column.
To avoid this, you can round your image widths upwards and distribute the overflow amongst all images in the row. This is a little more complicated than the previous method, but it does give a better result.
There are three more numbers you need to calculate.
var imagesPerRow = windowWidth / unroundedImageWidth
var numOfRows = Math.ceil($('.gridContainer img').length / imagesPerRow)
var spillage = windowWidth / roundedImageWidth - windowWidth // Pixels we have to lose
Now it’s just a matter of distributing the spillage.
var i = 0 // Loop counter
while (spillage !== 0) {
// Set the width of all images in column i to the width of that column - 1
$('.gridContainer img:nth-child(' + imagesPerRow + 'n-' + (i+1) + ')')
.width($('.gridContainer img:nth-child(' + (i+1) + ')').width() - 1)
spillage--
i++
}
There should no longer be more than a single pixel difference between the widths of the images.

It's because of rounding errors. What you do is fill the grid with 100 scaled images, depending on the browser to wrap to a new line when the image doesn't fit in the current row any more.
Now imagine a width of 305 pixels. Your formula gives an image width of 100 for that, so you get 3 images in a row and the next one wraps to the next row, leaving 5 pixels blank at the right border.

i think you should also add padding:0; to body its missing from your code.
Try it and even better just make a jsfiddle then it would be easier to check for everyone.