Libgdx Background getting slightly pixelated - libgdx

Okay so I have a image and it the same size as the width and height I have set up for the camera, but it look slightly pixelated. I don't readjust the size or anything but edges on everything look slightly off. This is just for a menu so I'm just using a Texture and using
sb.draw(image, 0, 0)
anyone have any ideas?

Related

CSS sprite vs Image during browser zoom

I have many small icons in my website. Instead of loading all of them independently, I am thinking of using CSS sprites due to performance gain.
Consider the following code
<div style="width: 24px; height: 24px;background: url('img.png') -10px -10px;"></div>
vs
<img src="css-sprites.png" style="width: 24px;height: 24px;">
As expected, both gives same result. When loading as an image (second case), if I keep resolution of actual image a higher value, say 128*128, and using 24*24 for display, I am getting better resolution even when we zoom the page in browser (tested in mozilla).
But when using css sprites, since I have to keep the same display resolution in the sprite, the image gets blurred when zooming.
Is this expected behavior or am i doing something wrong? Is there any way to overcome this issue when using css sprites?
I do not have much experience with html and first time going to use css sprites. Please help.
Edit: also, many posts I could see in internet about cross-browser issues while zooming. Is this some point of concern even now?
If your sprite size is 200x200 px, and you want to get better resolution by zooming - make you background-size: 100px 100px;. So if you will zoom to 200% - the quality of you image will still be good. Obviously, your sprite image should be twice bigger the size you are going to use on your website. To avoid problems - do not mix % and px or any other different units in one background-size. Use only px in your case and everything will work just fine.
Summarizing. Make sprite twice bigger, set background-size twice smaller the size of sprite image. Tested it in Chrome and FF. Works fine on zooming.
If you are familiar with svg files - try to do your own vector font (for icons) using http://fontastic.me/. No scaling issues will disturb you. You can set size by font-size and make them any color by color in CSS, like a text.

How to resize canvas and its background image while somehow maintaining the co-ordinate scale?

I want my canvas and background image to scale to any browser size which I have learnt is possible through this.
<canvas id="canvas" style="width:100%; height:100%;
background-size:100% 100%; left:0px; top: 0px;">
Setting the width and height using percentages causes whatever I draw on top to come out blurred.
The reason for this I read is that it comes out blurry because the width and height of canvas set using css is different.
It is absolutely imperative that I keep track of the co-ordinates since I have written a collision detection logic using the original size of the image.
Is it possible to dynamically change the canvas size to fill the screen, redraw it and ensure that the collision logic works perfectly without blurry drawing on top?
Lets take an example here. The image floor.jpg that I want as the background of the canvas is 1200X700. I want the canvas to be 100% of the page width and height. My animated player that moves on top of it requires collision detection with walls which I have coded keeping in mind the 1200x700 image.
I have gone through the various similar question on this site, but can't seem to figure it out.

Make images larger in HTML with no blur

I have been messing around with some new ideas in Javascript, but I'm not very good at making extremely detailed images in Paint, Paint.NET, etc. The problem is when I have a 64 * 64 image or an 8 * 8 and I want it to display 640 * 640 or 16 * 16; the images get blurry. I've seen many other forums and things were people ask this question or a similar one, but I'm relatively new to this and don't want to make the image larger in photoshop or whatever. On a similar note, can I display only part of an image at one time but have a larger image than shown, so that I don't have to make multiple images of the same thing?
Maybe this CSS attribute on your img helps:
image-rendering: pixelated;
I found it in this blog post:
https://css-tricks.com/keep-pixelated-images-pixelated-as-they-scale/
The reason your images get blurry when enlarged is because it is a rasterised graphic (pixel based image) and not a vector graphic (path based image).
When you try to enlarge the rasterised image, the pixels expand in size too which leads to the lower quality/blurry result (also referred to as 'pixelation').
The difference between vector and raster graphics is that raster graphics are composed of pixels, while vector graphics are composed of paths.
Source: http://pc.net/helpcenter/answers/vector_and_raster_graphics
You can't make it bigger without the picture becoming blurry. You are using a raster image. A raster image is an image that is made up of pixels. a color is assigned to each individual pixel. If you enlarge the picture. Each pixel will just be scaled so that it takes up more space on the screen. This will cause the image to appear blurry.
Here's an example:
rrr
rbr
rrr
"r" is a red pixel and "b" is a blue pixel. The dimensions are 3*3.
If you try to make the dimensions larger than 3*3, lets say 6*6, this happens.:
rrrrrr
rrrrrr
rrbbrr
rrbbrr
rrrrrr
rrrrrr
With the image was enlarged, each pixel just became bigger. In the larger image, each 2*2 square was originally 1 pixel in the original image. Now with this example, the new image wasn't blurry because it was just a square. But if you have a more complex image, it becomes blurry.
To fix your problem, use a vector image. A vector image is different from a raster image. Instead of being made up of pixels, it is made of shapes and lines and stuff like that. Each shape has a width, height, x coordinate, and y coordinate. Some shapes have even more variables. Because of this, vector images can be zoomed in indefinitely without becoming blurry. Sometimes when you zoom in on a vector image the quality even becomes better!
Here's an example:
rrr
rbr
rrr
Again, "r" is a red pixel and "b" is a blue pixel. Let's say this image has a width of 500. But you are zoomed out so far that it appears as a 3*3 square on the screen. In the center of the image is a blue circle. Now it doesn't look like a circle because it only takes up one pixel on the screen. So it looks like square. The circle has a fixed radius. and it is located in the center of the image.
Let's zoom in:
rrrrr
rrbrr
rbbbr
rrbrr
rrrrr
The image still has dimensions of 500*500. It is just zoomed in farther so that it takes up 5*5 on the screen. But the circle looks less like a square and more like a cross. and a 3*3 cross looks more like a circle than a 1*1 square.
The farther you zoom in, the more the image will look like a circle. But since you are using a raster image, enlarging it will result in a blurry picture.
To fix your problem use vector images instead of raster images.
For any form of res-sizing images, you will need a Vector-formatted image.
Vector formats are of the following:
CGM
Gerber format (RS-274X)
SVG
Image File Formats - Wikipedia
Use vector based graphics (svg), not raster bitmaps (jpg, png, gif).
Good thing about SVG is you can add CSS and JS to interact with it in a webpage.
Check this article on how to interface with the SVG

Why SVG image gets ugly resize with CSS (Chrome, Firefox tested)

I can reproduce this issue in both Chrome and Firefox.
This is SVG image in question:
https://www.iconfinder.com/icons/284101/editor_hambuger_list_menu_view_icon#size=512
And this is the minimum code which reproduces the problem:
<img
style="width: 15px; vertical-align: middle;"
src="data:image/svg+xml;base64,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" /> Menu
You can play with it and see it in action at:
http://jsfiddle.net/adamovic/s3dZ2/1/
Anyone has an idea why this Scalable Vector Graphics gets resize where lines becomes unproportional and also any idea how to fix this good?
BTW, in production I'm resizing this image to 1EM, to appear next to text "Menu" but to reproduce this issue it is the simplest way.
UPDATE: Updated example from 11.5px to 15px, reproducing same issue.
In production I'm using width: 1EM; or something like that for responsive design, any idea how to responsive scale this image so that lines are proportional?
Maybe some fix like min-width and max-width could work, but I couldn't make it work ever with some mozilla image specific commands.
At 11.5 pixels in with the height of the image should be 6.3 pixels. Of those, 1.1 pixels should be the height of each black line, and 1.5 pixels the height of each white line. And on top of that the browser resizes the picture to 6 pixels height.
If the image had 1 pixels for each line (both white and black) and the size multiple of 5, it would look great.
Later edit
In the given picture a black line is 16.67% of image size(all lines reprezent 50%) and a white line is 25%. So... for a height of 8 pixels the a black line has a height of 1.3 pixels and a a white line 2 pixels. On paper the smallest image that looks good and unaltered has 2 pixels for black line and 3 for the white line, meaning an image with 12 pixels height.
Basically if one pixel has to share both white and black lines the browser will create a shade of gray that is the average of the two as it can only display one color.
EX: a pixel has to show 0.67 white(#FFFFFF or 255,255,255) and 0.33(#000000 or 0,0,0) black:
0.67*255 + 0.33*0 = 170.85 (aproximatly 171) so the color displayed is (#ABABAB or 171,171,171)
Theoretically, SVG image is infinitely scalable. In practice however, the screen has limited resolutions, so if you scale an SVG too small, it won't look very good due to pixelations.
To avoid this problem, you need to set a minimum size for the icon at the point where it still looks good. High quality small-sized vector iconsets would usually be designed to have in such a way that their major lines lie in a grid of integer proportion for many different sizes, so that they will look crisp on different sizes; some icon designers might also provide a separately-drawn raster icons for low resolutions.
Inferring from the size declaration in the SVG, the icon you linked seems to have been designed for 22x12 or multiples of it.
On small sizes, you probably should also use media-queries so that small icons are scaled in a step-ladder of sizes with sizes that are known to look good rather than strictly depending on the viewport size.

scaling logo in html5 <canvas>?

Having trouble scaling with . It seems to make sense to code up a drawing in canvas to a fixed size (ie 800x600) then scale it for specific locations - but sizing occurs in 4 places: 1) in the context definition (ie ctx.width = 800 2) with ctx.scale; 3) in html with
I can scale it with ctx.scale(0.25,0.25) and use but this doesn't appear right - it seems to want the scale to be proportional.
css sizing simply makes it fuzzy so not a good way to go. Any ideas?
Actually, you can resize a canvas using stylesheets. The results may vary across browsers as HTML5 is still in the process of being finalized.
There is no width or height property for a drawing context, only for canvas. A context's scale is used to resize the unit step size in x or y dimensions and it doesn't have to be proportional. For example,
context.scale(5, 1);
changes the x unit size to 5, and y's to 1. If we draw a 30x30 square now, it will actually come out to be 150x30 as x has been scaled 5 times while y remains the same. If you want the logo to be larger, increase the context scale before drawing your logo.
Mozilla has a good tutorial on scaling and transformations in general.
Edit: In response to your comment, the logo's size and canvas dimensions will determine what should be the scaling factor for enlarging the image. If the logo is 100x100 px in size and the canvas is 800x600, then you are limited by canvas height (600) as its smaller. So the maximum scaling that you can do without clipping part of the logo outside canvas will be 600/100 = 6
context.scale(6, 6)
These numbers will vary and you can do your own calculations to find the optimal size.
You could convert the logo to svg and let the browser do the scaling for you, with or without adding css mediaqueries.
Check out Andreas Bovens' presentation and examples.
You can resize the image when you draw it
imageobject=new Image();
imageobject.src="imagefile";
imageobject.onload=function(){
context.drawImage(imageobject,0,0,imageobject.width,imageobject.height,0,0,800,600);
}
The last 2 arguments are the width an height to resize the image
http://www.w3.org/TR/html5/the-canvas-element.html#dom-context-2d-drawimage
If you set the element.style.width and element.style.height attributes (assuming element is a canvas element) you are stretching the contents of the canvas. If you set the element.width and element.height you are resizing the canvas itself not the content. The ctx.scale is for dynamic resizing whenever you drawing something with javascript and gives you the same stretching effect as element.style.