Random svg lines appearing when panning in safari - svg

I am experiencing two weird things happening with svg rendered in safari (works fine in Chrome/Edge/FF and heck even IE)
Lines not defined in SVG will appear and disappear randomly when panning around.
Lines defined in SVG might disappear randomly when panning around.
Not really that easy to describe so I made a video for it
https://youtu.be/BqlItab0k_g
I did not use any fancy SVG feature like script or media query. The only elements used are text/path/rectangle.
The SVG is generated by me and optimized using SVGO
[Codepen](https://codepen.io/alt22247/pen/vwzBmL)
The svg is base64 encoded since I can't upload svg to code pen. Had to use code pen instead of SO built in since the base64 encoded img text exceed SO limit. Feel free to decode it back to text.
I can't think of any way to mess up the SVG without causing a parse error so I believe this is a Safari bug. But we need to support Safari regardless (typical life of a web dev).
So the question is: What is causing this and is there any work around I can do rather than wait for Apple to fix it 10 years later?

Related

FabricJS Text vs NodeJs Node Canvas Text - The Fonts Look Different

I am really stressed out with this, i have built an entire designer with Fabricjs, gone through some right hoops with the text to make it work how it's needed. The problem is now when the data from the canvas is sent to the server for a full resolution render with NodeJs (fabricjs in node) the fonts are coming out looking different to they do in the browser.
All the fonts are installed on the server, and the correct font does render, it just seems to have different spacing between the characters even though the fabric version is the same and all the extension code is the same on browser and server side, all the TTF fonts are the same etc etc
Here is the browser version:
And here is the node js version:
As you can see the font is correct on the node one compared to the browser one, but it's being rendered slightly differently.
Is there a solution anyone knows of to fix this?
I don't believe that there is any way to solve this problem when using fabric.js
Text in fabric.js can be scaled arbitrarily, but then it is rasterized and displayed as a canvas object like any other image.
You can see in the fabric.js demos that the text will stretch like an image until your input is complete, then it re-renders to a new image at that scale.
Knowing that this is how fabric.js handles text, it is possible to select two scales that produce quite different results:
In the image above you can see that the two fonts are pretty much the same size, but the one on the right (slightly larger) has been rasterized such that it appears to have a bolder appearance. It's the best example I could reproduce with limited time.
This is why rendering the fabric.js objects in your browser at a smaller resolution than the server will lead to the font appearing slightly different.
If you try rendering the browser version at the same size as the server you are likely going to get the same results.

Batik/Rhino JavaScript support?

Just want to get a sanity check on this before wasting too much time - does Batik actually have usable JavaScript support in its SVG display and rasteriser?
Problem: I've got code which generates SVG files, using a few thousand lines of fairly complex JavaScript. This works on Firefox, Chrome, Opera, Safari, and IE9. I've spent the morning trying to get Batik to display a sample SVG file (in Squiggle) and to rasterise it to png/pdf/etc. I've already fixed one problem (I had to move a text node into the DOM to get splitText to work), and the next problem is only a few lines down (nodeValue.trim() doesn't work on a text node).
Just about to give up and ignore Batik (v1.7, downloaded yesterday), unless someone has some positive experience of it?

Transitioning svg text opacity

Has anybody ever had any issues with transitioning the opacity of an SVG text element? I'm using both the fill-opacity style and the stroke-opacity style to fade the text elements into and out of existence. It works fine on most browsers, but doesn't transition at all in Chrome on Mac -- the text just pops in and out all at once.
I tried setting the "opacity" attribute in addition to fill-opacity and stroke-opacity and that does seem to make it work, although now I see a weird flicker effect just before and after the transition runs. It's like it's setting it to opacity=1 for a split second before it sets it to 0 and then transitions to 1.
Another interesting thing is that other shapes (circle, rect) fade in and out just fine with nearly identical code to what I'm using with text.
This does seem to be weirdness with a specific browser, but I'm wondering about other people's experiences with opacity on text elements. Are there tricks to get it to behave consistently?
What version of Chrome are you using? I noticed a bug in Chrome dev some time ago when working on the word cloud but it appears to have been fixed as of 19.0.1077.3 dev. Perhaps the fix hasn't made it into your particular version yet?
In my case, using opacity fixed the problem temporarily. The flicker effect could be due to exponent notation not being parsed for very small numbers; you can try using 1e-6 instead of 0 to get around this.
For an animation I made some months ago I toggled the style and used webkit-transition, in combination with visibility: hidden. This seems to work well. If that doesn't work, you could try transitioning to an opacity near zero.

Why does IE change the color?

I've placed an image on top of a div. I'm trying to blend the image into the div (The div is a solid color). In Google Chrome, it looks great! The colors blend perfectly. In IE 7, however, the colors show a hard line even though they should be the same color! After some examination (a print screen put into paint.net to check the actual RGB values), IE 7 is actually lightning up my image.
The blend has to look seamless. Google Chrome was fine with this thus far. Any ideas why IE 7 wont display the color right?
The two browsers are using different rendering engines. There are minor differences between them in how they render graphics, particularly jpegs.
The differences are minor but unavoidable.
Most of the time it goes unnoticed; it only makes an appearance in cases like yours when you try to position it against an element with a solid background colour that is supposed to be the same.
You may be able to resolve the issue by using a different image format. Try saving the image as a PNG. PNGs tend to be rendered more accurately between the browsers than jpegs, so that might be enough to solve your problem.
If that doesn't solve your problem, you could try using PNGs alpha transparency feature to produce an image with a fade to transparent at the edge, and then overlap the background colour behind it. This will definitely give you a smooth transition, but is a bit more technical, so harder to achieve. It will also give you problems with older versions of IE (IE6 for sure, I think you'll be okay with IE7), as they had some major bugs with PNG transparency. (If this is an issue for you, there are work-arounds for this; google IEPNGFix for more)

alpha transparency solution in IE

I am building a website with a TON of png-24 files that have transparent background. In IE 6 they obviously aren't displayed correctly, so I need some sort of reliable, good solution that will fix the PNG problem in IE and require little work and be reliable. Any good ideas?
For IE6 transparency I follow a personal flow:
1. If there is just one or two PNG images (like a logo, or a normal image) I just use filter:
#selector {background:none; filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='test.png', sizingMethod='crop');}
Problems: If applied to a link, it will no longer be clickable. Possibly apply to the h1#logo and have the a be transparent.
2. If I have a lot of 24-bit PNG files, or special use cases (repeating background, etc), I use DD_belatedPNG
IMPORTANT FOR IE7 + IE8: You cannot animate or combine the filter:alpha (which is used for overall opacity on an element in IE and also used by jQuery to set opacity) property with 24-bit transparent PNG images. It changes it to look like 8-bit transparency, with everything that is not 100% opaque or transparent taking on a black background.
Here are a few good png fixes for ie6:
http://labs.unitinteractive.com/unitpngfix.php
http://www.twinhelix.com/css/iepngfix/
There are a lot IE PNG fixes on the net, which basically all work with the same technique. The older Internet Explorers do not support alpha in PNGs directly, but they all have a filter that does so. So writing the following code as part of a css of an object puts the image in the src to the background of the element:
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='image.png');
That way, you can easily display transparency in the Internet Explorer. However it's a lot easier to just get one of the png fix scripts (in JavaScript) and include it to your page inside of conditional comments. Then the script will make all your images working automatically.
We used Dean Edwards' IE7 for this. (So named before IE7 came out.) It's been good for that kind of thing.
There are currently many options to get this working. The standard is apply a DirectX filter through CSS to change make the PNG transparent in IE6. There are even scripts that will automatically do this when the webpage loads from an IE6 or less client.
http://www.google.com/search?btnG=1&pws=0&q=transparent+png+ie6

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