I'm using Swiffy to render onto a hidden canvas so that I can take the result and use it elsewhere. The problem I'm running into is that when I resize the container div for Swiffy it won't make the actual canvas any bigger than the available viewport size. If I set the dimensions of the Swiffy div larger than the viewport then the canvas will only get as big as the viewport - it doesn't want to put any part of the canvas offscreen.
I'm sure this is for efficiency, there's no reason to render something if it's offscreen normally, but I need to have Swiffy render it all the time, at whatever size I want.
Additionally, Swiffy just plain refuses to do anything if the Swiffy container div isn't attached to the DOM. (Forces the canvas to have a width and height of 0).
Is there a way around this without having to dig into the (obfuscated) Swiffy client runtime and modify it? How can I trick Swiffy into rendering larger than the viewport size?
Edit: I was actually able to trick swiffy into rendering larger than the viewport by changing window.innerWidth to whatever I want. That's a really ugly hack though and I hate to overwrite that as it causes a lot of issues.
If your swiffy runtime version is 7.3, you can hack the js directly.
Just remove or comment "b.xj(c);" in g.Tp() function. I don't care any advantage of offscreen rendering. At least, it works now.
I think it's a serious bug.
Note that it's good in iframe, no need to hack.
The only way I could figure out how to do it is to edit the Swiffy runtime and replace all instances of window.innerWidth and window.innerHeight with whatever size I wanted.
No ill side affects that I could see, though this is obliviously less than ideal.
If someone comes up with a better solution I'll absolutely accept it.
If i get the problem correctly, for rendering larger than the original swiffy you can put swiffy in a div and scale it
To have swiffy restrict to its original output scale as from flash, you can place it in an iframe
Related
I generally use .getBoundingClientRect().width when developing html5 banners to get the width and height in the JS. This is used to do animations per size with (if 120x600, if 160x600 etc). I have noticed on a recent Chrome update if the browser is zoomed in or out it returns an incorrect value (out by 0.0001px) which means the if statement / animations fail.
I tried .getBoundingClientRect().width with a round to nearest 10 function but i felt it was too hacky.
Another solutions was grabbing the height and width from the css style sheet.
Is there a better solution for doing this without hard coding in the dimensions of each banner size?
The Problem:
I've been seeing problems with the native iOS UIWebView with regard to CSS3 transform:scale3D(scalar, scalar, 1)
We have an <iframe> which contains pixel-perfect art, consisting of many elements (text, rectangles, videos, etc), and my task is to scale the <iframe> where it fits fullscreen, not just the designed 320x480 or whatever
First of all, touch events aren't propagating through at all. Secondly, when the user holds down on the <iframe>, they can see DOM outlines for the elements at the prior, incorrect locations, at incorrect sizes (before the <iframe> was scaled to fit the screen)
The blue area should be the entire screen, not the original location
To top it all off, sometimes the scaling introduces random horizontal / vertical lines where the UIWebView decided not to repaint
My Attempts:
I tried using css zoom: which I understand is somewhat of a replacement for the <meta> tag viewport zooming, but I was still seeing random unpainted lines. I'm not exactly sure if I tried using hardware acceleration (transform in z / 3d space) but I'm pretty sure I did, the same as with the regular transform:scale3d approach
I also tried to crawl the configuration object, which has properties like x, y, width, height, but it seems like some properties need to be rounded where others do not (text font size and letter spacing for example, border widths etc). Rasterizing is causing a headache and I can't seem to get a pixel-perfect, scaled <iframe> I'm not sure which elements support decimal px CSS, so I'm considering converting everything to em
I haven't yet used an actual <meta> tag because it can't be dynamically appended.. needs to be on the HTML before the DOM is rendered. Another reason I didn't use the <meta> is because I need to know the viewport size prior to writing the <meta> properties (I can possibly query from out native counterpart if someone confirms this solution works)
The Question:
Has anyone encountered this problem before? Is it possible to get a pixel-perfect, scaled representation, given that the scalar may be 1.333333? I know that Apple is replacing the UIWebView with an embeddable Safari implementation (mobile web works fine for my usecase, just not native iOS), but in the meantime, is there any hope for iOS? Links highly appreciated! Thanks in advance..
My coworker found the answer!
Answer:
You can't scale an <iframe> from the outside DOM, you have to postMessage() into the <iframe> and use document.body.style.webkitTransform = "scale(1337)"
Hope this helps somebody else in need!
Credit ultimately goes to http://adexcite.com/iframe_scaling_test.html
I've been working on a slideshow script that uses CSS3 transitions, or jQuery's animate when they are unavailable. I've created a custom function to do the slide animations, which does so appropriately. Everything seemed to be working fine, but I've hit a major snag during testing.
For one reason or another, there is an large delay applying the jQuery CSS before and after the transition on large slideshows. For example, the slideshow in the link below is around 9900 pixels wide (container width, most of which is hidden). The container is maneuvered to display the appropriate slide, using CSS3 transition and transform properties. The delay occurs applying the CSS between lines 75 - 82 in the paste below. In particular, applying the 'transition' CSS causes the problem. Add the 'transition' CSS to the stylesheet (rather than applying it with JS), and delay disappears. This isn't really a solution however, because we only want to use CSS3 transitions on specific properties, that can vary (using 'all' in the stylesheet would transition some CSS that we don't want to animate, but change regularly).
Animation function:
http://pastebin.com/9wumQvrP
Slideshow Demo:
http://www.matthewruddy.com/demo/?p=2431
The real problem is with iOS, in which the slideshow (and even the browser sometimes) becomes completely un-usable. I can't pinpoint any errors, and have really exhausted my knowledge of debugging JS. I'm sure it is related to this section of the function after playing around a bit, and disabling CSS3 support within the plugin altogether removes the problem completely.
I'm completely stuck, and really appreciate any help anyone can give.
--- Edit ---
I've tried applying the CSS with native Javascript rather than jQuery's .css function. Same results, no better performance. Also worth noting that this isn't happening at all in Firefox, and seems to only be a problem with Webkit browsers.
Anyone with a solution, would happy to make a donation towards a few beers! I really cannot figure this out!
--- Second Edit ---
Ok, so been debugging and I can see that the slowdown is caused by the browser repaint cycle that is taking a very long time. Is there a better way to handle this that the way it is already doing? Positioning the element absolutely is a known way to reduce repaints, but that isn't really working because the slideshow is responsive. Absolutely positioning the slide images or the slides themselves causes it to collapse.
--- Third Edit ---
A day later, and I've made some progress. Adding 'transition: all 0s ease' to the elements stylesheet CSS has gotten rid of the repaint caused by adding the inline CSS transition property via the custom animation function mentioned in the original post. This causes a significant performance gain, especially when removing the inline CSS transition property when the transition itself has finished.
Good stuff! However, now there is still a slowdown when the inline CSS translate is being removed (that was used to create the hardware accelerated transition effect itself) after the transition, and the left positioning is being applied. When the two happen together, there is a slowdown.
Breaking them up into two separate tasks (the translate removed, then the left position added in a setTimeout with no time specified), again gets rid of the repaints = performance gain, and looks likes problem solved. But sometimes, the CSS transition property isn't get negated fast enough, and the translate removal gets animated. No good, and don't know where to look next to work around it.
I think the problem is you're loading HUGE images :)
They are too big for the container you have them in, so you scale them down, which is even more resource intensive.
Try resizing them.
First of all congrats for your debugging!
I have been working on the exact same stuff lately and found out that ios devices don't support a large number of images positionned in the same page. It causes crashes and the only solution I found was removing elements instead of just hiding them. The downside is that removing and appending elements causes lags so you have to do it cleverly, when your transitions are done. I thought the best way to go was keep 3 or 5 images in the DOM and replacing the rest with thumbnails of the images, resized to fit the original. When transitions are done, I'd just put the large images back into place...
Hope this helps you a bit on the ios problem at least...
After spending some time analysing your code TimeLine with Chrome Dev Tools, I believe there's some optimization you could do.
As far as I can tell, every single one of your 16 images gets fully repainted every time an animation is requested. This seems quite obvious to me, as there are 16 images in your example, and the Chrome Dev Tools reports 16 long "Paint" executions every time in hit "Next".
In my humble opinion, you should figure out a solution that considers only translating two images: the one you want to hide and the one you want to show. So, consider please, not moving the rest of the images and, instead, leaving them all side-by-side to the shown image.
One more thing, using scaled down images is probably making the paint cycles quite longer. Avoid them whenever you can.
Well, think I've managed to figure it out! Just so you know, original post links don't reflect the changes as I've done them on my localhost environment.
Absolutely positioning the slides container has fixed the problem that was occurring with repaint speeds after the transition had taken place (whilst applying CSS properties). Obviously taking them out of the DOM has done the trick, allowing painting to take place much more efficiently.
I originally didn't try this too much because I knew this would add a lot of work to the resizing functionality. I had originally intended to not resize at all in JS, and rely on percentages to do the dirty work. Absolutely positioning the container would cause the slideshow viewport to collapse, rendering the native resizing useless.
However, I was already having problems with sub-pixel rendering in other browsers anyway, so I guess it was time to bite the bullet and rely on fixed pixel values. I then used JS to handle the resizing, using the window resize event. All seems good, however the slideshow was still collapsed due to the positioning. Assigning height values wasn't working correctly, so was at a bit of a loss.
Thankfully, I came across a neat little trick of setting the 'padding-top' of the slideshow viewport to a percentage value, dynamically calculated (desired slideshow height, set in the settings panel for this script, divided by desired width). As padding-top percentages are relative to the width of the element, this did a great job of providing responsive height and correcting the viewport again (no longer looking collapsed).
Here is some info on using padding-top for responsive elements that maintain aspect ratio. Great little trick: http://f6design.com/projects/responsive-aspect-ratio/
All is good now, and things are working well in iOS and webkit browsers. Everything is extremely quick and working as it should. Four days later, and it is finally figured out. Not happy about having to resort to JS for resizing, but I guess it was always going to happen due to percentage inconsistencies between browsers. Lots of decimals = no good!
Thanks to all who tried to point me in the right direction. Definitely got me thinking, and learned a lot of debugging skills that I can use again to make sure transitions are performing well. Thanks again!
not sure if this helps or not but I noticed you use 3d translation - I would think a simple 2d translation would be enough especially since your third parameter is 0 and might accelerate the issue, also go with fewer images as Armel L. suggested, don't have an iphone to test though... alternatively, this is a solution I used before css3 but should still work move the element containing the images using javascript by modifying left (?and top - the demo only moves left and right though? without the transition effects) and this way you can fine-tune the refresh rate which I think might account for the slowdown... you can go as low as 18 fps without anyone noticing, might even be good enough with just 16fps
I had this when I was first designing a magazine carousel-style page device.
If you have a series of images within a long "tray", even if they are not within the viewport, they will still take up ram, and you can effectively have five or so before leaks and nastiness begin to happen.
What I found works is "hiding" them ... But make sure they take up the physical space necessary.
What I also found worked was that one could make the 'previous' current and 'next' image are visible and move the tray, 'unhiding' them as they reach those three positions.
In my own system, I skipped the 'tray' holding e images and only had them at -100% width, 100% width and the current one a 0.
I never had much luck with the typical long-tray carousel with large scale background images... Especially with css3 acceleration.
jsfiddle: http://jsfiddle.net/UenFN/. Notice the slight, brief pixelation after the animation. This error only happens in WebKit browsers.
Using jQuery, I have an image resize into a smaller one. The new dimensions are precisely half of the old ones. Right after resizing, however, the image appears slightly pixelated, then about 2 seconds later it looks better.
How can I fix this problem?
EDIT: Still no progress. Any idea is appreciated.
The solution is to enable the Hardware Acceleration in Webkit.
img {
-webkit-transform: translate3d(0, 0, 0);
}
I have a small library which resize image and HTML to always fit the parent div. Safari bugged me with its own unique way to do a quick and dirty pass before doing the bicubic one. Forcing the hardware acceleration solved the issue, In my case as I do a lot of resizing I do notice some performance degradation yet in the end the overhaul result is more appealing.
You can test this fix here: http://www.visualfox.me/app/nanjing-2014
Under Safari the image used as a mask is never pixelated, regardless of the resizing, upscale or downscale (just resize the browser to test it). You can compare that with this other demo which doesn't use the fix: http://www.visualfox.me/app/bold
Notice how the logo is temporally pixelated when you resize the browser.
my! enjoy!
I discovered that the only time it does not do it is when the size upon completion is the native image size.
from 150 to 300 pixels, no pixelation...
http://jsfiddle.net/UenFN/1/
and from 450 to 300 pixels, still no pixelation...
http://jsfiddle.net/UenFN/2/
So the fix, or workaround, would be to make sure your final size is the native image size wherever possible.
You could use an image appropriate to the dimensions you are going for.
If you can't do that then you could use a callback method to replace the resized image with an image that is the size of the new dimensions. What you are doing is no different than stretching an image (in fact thats exactly what you're doing) so there is going to be pixelation.
In order to fix this, I inserted the same image a second time, but with the dimensions I want to use. At the millisecond after the animation, I replace the main image with the previously hidden image.
jsfiddle: http://jsfiddle.net/wLwrc/1/
Solved in 2013. https://bugs.webkit.org/show_bug.cgi?id=74600
image-rendering: optimizeQuality;
I had the exact same problem. I changed the *.jpg that I was animating the size of, to a *.svg and the pixelation went away.
I was wondering how to achieve the native scrollbar effect which TheFWA (thefwa.com) has managed to do pretty well (I am not a fan of Flex scrollbars).
I found this post (http://stackoverflow.com/questions/318675/how-can-i-create-a-flex-application-with-dynamic-height), and implemented the technique, as I am calling a JS function through ExternalInterface every time, when the flash object changes size. This JS function simply resizes the div which holds the flash object, which creates the native bars.
Unfortunately, when I resize quite rapidly (from 800 to 1800 height, for instance) the flash object simply gets warped for several milliseconds (as if it hasn't changed its size, but simply got pulled in all directions). After these milliseconds, things get back to normal, but the whole situation is really visually annoying.
Originally I thought that it's simply a timing issue, but after a bunch of attempts to set a delay, the effect was the same ... just delayed.
How can I resolve that? I know it's technically possible. Just take a look at TheFWA, and see how smoothly flash and the browser are communicating with each other to make the native scroll bars work, without any flickering, or mismeasurement
This is an issue that appeared since Flash Player 10 and is still happening up to FP 11 beta.
When you resize the DIV that contains the SWF, the SWF itself is resized, therefore you "ask" the player to redraw the content. But the thing is that this redraw creates this ugly flicker.
The workaround it to not resize the SWF DIV at all and to resize another empty DIV, so you force the browser to update the scrollbar.
At this point when you use the scrollbar it won't move the SWF DIV (as it is probably often a position absolute full-size flash site) but then you create a simple JS callback to send the scroll values to your application.
It may sound as a much greater effort but it is not much actually, and at the end you will create a more flexible way to manage your application.
You can check that in use here http://www.andrefelipe.com/
And the source code is at my framework https://github.com/andrefelipe/fabricaframework/blob/master/src/fabrica/external/Browser.as
The flash content on that site has fixed size. What they did is to put the swf file in a centered div. Something like this:
...header stuff...
<body>
<div id="flashContent" style="width:960px; margin:0 auto;">
...the flash content goes here...
</div>
</body>
The width of the div container should be the width of your flash movie.
If you want to resize the flash movie then take a look at swffit
That site isn't doing anything special, simply setting the height and width of the application and slapping it on the page - no resize is happening. If you simply employ the same technique (specifying a height for the app) then you will get the same results.
Am I missing something?