8 ms·

A new approach to text rendering

154 points by podgib 9y ago

pcwalton 9y ago
> One frustrating component of the above breakdown is the time spent recalculating styles. At this point, it looks like the only way to solve this within the current paradigm is to use CSS less and reduce the number of selectors in the application, but that’s going to be a hard fought battle given the huge number of themes in the ecosystem. This is a perfect example of why we need parallel restyling. :)
- Xeoncross 9y ago
  How would that work? Breakup the screen into chunks each CPU/GPU renders?
  - pcwalton 9y ago
    The same way Servo (and the work-in-progress Servo port to Gecko) does it. Compute styles for every DOM node in parallel, using a work-stealing scheduler to distribute nodes among threads in a thread pool. Parent nodes must have their styles computed before children, but other than that constraint it's an embarrassingly parallel problem.
    - revelation 9y ago
      Work-stealing scheduler, thread pool? What is going on here? Have any of you seen the kind of stuff recent games draw in 16 ms? It's amazing! They sure as hell don't use a work-stealing scheduler in a thread pool for single vertices, though.
      - pcwalton 9y ago
        Games are at an advantage because they can do a lot of up-front processing. They can statically schedule their content based on knowledge of the hardware, and programmers can and do even tell the artists to tailor their content directly to the system. Conversely, on the Web, we can't do any of this: we have no idea what the content is going to be like until we receive it, and we have to handle specifications that were written without parallelism in mind. All of the decisions we make have to be dynamic rather than static, which is why work stealing is especially effective. Besides, vertices are a much simpler problem than CSS styling. CSS supports hundreds of properties, all of which are parsed and cascaded differently. You have properties that are inherited and properties that are noninherited. You have properties that depend on other properties: for example, any lengths might be specified in terms of ems, which means you have to have resolved the font size first. You have properties that result in completely different render trees, for example "display". You can't effectively throw stream processors like GPUs at the problem (believe me, I've tried). Could we do better? Sure. But every proposed replacement for CSS I've seen (e.g. Cassowary) has made the complexity problem worse. And most native styling solutions I've seen are usually just very slow implementations of CSS. Separating presentation and markup is just hard, no matter what.
        teleclimber 9y ago
        > But every proposed replacement for CSS I've seen (e.g. Cassowary) has made the complexity problem worse. Hi, what other proposed replacements for CSS do you know about? I'm interested in seeing what problems they ran into. I need to go look at Cassowary again. IIRC it's a solver, so sometimes the layout won't be what you expected, and it's very hard to know what to change such that it does what you want.
        pcwalton 9y ago
        Cassowary was admittedly a bad example, because it's a layout algorithm rather than a style system. But I've seen folks suggest that we just replace CSS with TeX, for example. Using TeX would make this problem a lot worse, because styling TeX involves expanding textual macros. You would lose any possibility of parallelism, ever.
      - zubat 9y ago
        Or to put it in other words: browser technology is asked to do so much that they had to go invent a new language to keep up. So that they could serve ads. For us ordinary folks trying to write good applications that can be maintained by one person and scale reasonably well, there's justifiable reason to jump off this rollercoaster and work in a more humble environment with modest perf/safety tradeoffs and native code executables(e.g. Go, Basic, Pascal).
        justinmk 9y ago
        The "so they could serve ads" meme is facile, reductionist, sophomoric. Actually, the fact that Google et al. were able to identify a profit function that could be optimized to fund the last 15 years of technology is an incredible achievement. In ~2000 it wasn't at all obvious that the internet could find a robust funding model. Where the funding comes from is practically irrelevant, specially if it is a feedback function (i.e., an economic phenomenon, not "phone the legislature to fund more research!!1"). New funding models are good, too, of course. But the tone of the anti-ad camp is asinine.
        zubat 9y ago
        A realpolitik view of tech only holds under the assumption that any new technology is good technology. It allows nothing to balance or sustainability, and I believe the trajectory of the Web is unsustainable and therefore fundamentally doomed despite its near-term wonders. The SV camp has said nothing to convince me otherwise.
        coldtea 9y ago
        >Where the funding comes from is practically irrelevant, specially if it is a feedback function (i.e., an economic phenomenon, not "phone the legislature to fund more research!!1"). I preper phoning the legislature -- more democratic and less private interests-driven.
      - Manishearth 9y ago
        Games are a completely different problem space. "styling" is a concept that games don't have; games don't deal with deciding which thing has which style at runtime. Browsers do, because they are just given CSS and have to handle the cascading and assigning of styles on their own.
        revelation 9y ago
        Of course they do, modern games are a complex interaction of many different shaders operating on all levels of abstraction on many different classes of runtime data that they compose, renew and adapt many many times in 16 ms. Is the whole CSS debacle a particularly unlikely concept to yield anything close to a reasonable performing implementation? Sure, but that is because nobody has applied the pressure necessary. People won't play a game that doesn't consistently meet a 30 ms deadline but they seem to happily put up with 3 seconds to final render and call it "amazing".
        Manishearth 9y ago
        Shaders are a completely different thing from styling (cascading). GPUs work here because games fundamentally operate on a list-like datastructure (the display list), with little interdependence. Styling on the other hand operates on a tree like datastructure (the DOM), with lots of interdependence. Cascading isn't something games need at all, and if it was, it could be precomputed. THis can't be done in webpages.
        mianos 9y ago
        Game engines are pretty much completely sitting on complex tree structures. Way more than the DOM. The main reason the DOM all looks so tricky is it is a hack on a hack on a hack. A lot of game engines have been rewritten from scratch many times over.
        Manishearth 9y ago
        Yes, trees are involved in games too, but not at the level I'm talking about. You don't have analogues for tree-structure-based "selectors" and anything more than straightforward property inheritance (e.g. inheritance of transformations in a skeleton) in game engines. CSS is much more complex in this aspect. The DOM having lots of legacy issues is not the reason styling is slow. CSS is designed for a lot of flexibility and can't be precompiled, which is why it is slow to style.
      - Rusky 9y ago
        Games do, however, use job systems just like that for plenty of things that aren't single vertices.
    - thomasahle 9y ago
      In css sibling nodes can certainly affect the position of each other, but that might be ok. A harder problem will be siblings that "run in" to each other, and overlap in various ways.
      - pcwalton 9y ago
        I'm talking about styling, not layout.
- panic 9y ago
  I dunno, I'd say it's more an example of why CSS isn't the right abstraction for styles in a text editor…
  - pcwalton 9y ago
    CSS is more powerful than anything that popular native text editors can do. As far as I'm aware, in native text editors, generally, style can't influence (block-direction) layout, and that's why they can get away with determining what's visible before restyling. Once you have styles that can influence layout, this dependency is reversed, so any native text editor will have to restyle off-screen lines just as a browser must. Is it worth restricting an editor to only styles that don't influence block layout? For example, should it be impossible for a theme to make comment lines taller or shorter? I don't know; it's a tradeoff between performance and flexibility. My feeling is that there's a lot more room to improve the implementation before we have to resort to reducing capabilities, but reasonable people can disagree.
    - kazinator 9y ago
      Should it be impossible for a theme to make comment lines taller or shorter? Of course not; everyting should be in the same damned monospaced font in a text editor for writing code.
      - capnrefsmmat 9y ago
        My Emacs Org-mode setup already has larger font (and taller lines) for headings, so this isn't too crazy. Not everything in a text editor is code; some of it is text.
      - aninhumer 9y ago
        Why does code need to be monospaced? I feel like the only reason we all do it is that it's always been done like that so it feels wrong not to. The only actual reason I can think of for it is alignment, and that seems like a minimal benefit really. Variable width text is generally considered easier to read, so why couldn't this also apply to code?
- pjmlp 9y ago
  This is a perfect example of why Atom should have been a native application to start with.
  - aninhumer 9y ago
    Eh, I feel like the web platform as allowed it to be massively extensible in a much more convenient and familiar way than a lot of other editors. I tried it for a little bit and it felt like the "Sublime Text but more open and flexible" that I really wanted. If they can work out a way to improve performance without sacrificing too much of that, it would be great.
    - pjmlp 9y ago
      As an Emacs fan, not really.
      - foldr 9y ago
        This isn't about emacs. Atom is for people who want an alternative to Emacs. If you only need to know JS and CSS to write an extension, that vastly increases the pool of people who are able to write extensions.
        LeoNatan25 9y ago
        That "pool" of people "able" to "write" "extensions" is exactly the people you don't want touching your text editor, or any software for that matter. Anyone that has a psychological barrier to take a look at a language that they are not familiar with, let alone a framework or an ecosystem, is not someone that I want being anywhere near the software I use. In an ideal world, I wouldn't want them to be anywhere near the web I visit either, but that is a lost cause.
        foldr 9y ago
        The quality of Atom extensions is good, so that's clearly not true. Also, you are going nuts with the scare quotes. I don't even see what point you are trying to make with those.
- twhb 9y ago
  Parallel restyling just kicks the can down the road, asking for free perf elsewhere because we still haven't made it fast. What we need is a low-level style interface - .style but for computed, not CSS-integrated, styles - and then to plug into that using CSS where appropriate, or custom JS where appropriate, or even framework JS. Let people control style selection in a real programming language and you've guaranteed that it can now be done in a way that's fast and suitable.
  - pcwalton 9y ago
    I don't necessarily disagree, but I'd like to reassess where we are in terms of performance once Typed CSSOM is widely used. Using Typed CSSOM to adjust the "style" properties of individual elements is awfully close to doing what you describe: the difference is that matching and cascading still happens, but the semantics become much simpler if you're adjusting individual styles, and it's not clear to me that most of the overhead can't just be optimized away at that point.
rjzzleep 9y ago
So, we're sort of simulating offscreen drawing by using a virtual dom? I mean don't get me wrong it's sort of nice that they did this as it's the only thing they could have done to deal with the issues I wrote in my 2014 blog post, but that also means that with a lot of effort the web is now able to do what quickdraw could almost 20 years ago...
- pcwalton 9y ago
  You've always been able to query layout information about DOM nodes that are off screen. The virtual DOM is used for other reasons.
  - rjzzleep 9y ago
    With all due respect, no it's not. This is exactly what people used to do to optimize drawing in intensive application. You only render the visible area. The entire post explains the supporting actions needed to accomplish this for the browser. Thats why at the end of the text they talk about exploring the use of the canvas. Here's an application from ~2000 https://www.macintoshrepository.org/2214-vncthing https://www.macintoshrepository.org/2214-vncthing The actual VNC canvas was offscreen and it would only frequently display the entire thing. Which made it for a long time more efficient than modern vnc clients. I think 2010 it was still better than any other VNC client on macosx. It's by far not an uncommon technique, it's just a pain to do when your target is markup, which is what this post is all about. Granted, it's more complex because a tile here is a chunk of markup rather than a piece of a pixmap, but still.
    - pcwalton 9y ago
      Your confusion (which is understandable) points to the reason why I dislike the word "render": it's extremely overloaded. Rendering as defined by QuickDraw (which you alluded to in your above comment) or the VNC client you linked to is really painting, which browsers only do for areas that are on screen or close to being on screen. Browsers have performed this optimization for decades. What Atom is referring to by "rendering" here seems to be applying styles to parts of lines. Styling is a higher level concept than vector graphics. Partial styling is something that browsers have wanted to be able to do for a while, but it's quite complex. I've never seen an implementation of partial styling in any UI library, and certainly not in QuickDraw or VNC, which have no CSS-like concept at all.
draw_down 9y ago
I still really wonder about the approach of using web tech for this editor. But I haven't tried it in a while so I will do that shortly. I have been wanting more Github integration in my editor recently, ever since I saw the Xcode demo.
- noway421 9y ago
  I'd think that the only text editor that web browser is competent to have is <textarea>
y_u_no_rust 9y ago
Seems like such a wasted effort due to technology choice
Anone33 9y ago
Then ship Servo. It's getting annoying seeing the Servo devs constantly patting themselves on the back about how smart you are and insulting other engines that are actually serving users.
- matthewmacleod 9y ago
  That’s unfair. It’s hardly “insulting” to talk about the benefits of a new approach. And as I understand it, Stylo will be shipping in Firefox this year.
  - pcwalton 9y ago
    I can't reply to the above comment because it's dead (and no, I didn't flag it), but you can try parallel styling out by building Firefox Nightly with --enable-stylo and enabling the preference in about:config.
    - Manishearth 9y ago
      It should be a pref switch in the next nightly on 64 bit linux and windows, fwiw.
      - nstart 9y ago
        that's good to know. I'm actively keeping up with FF updates (stable) and it'll be good to try the nightly updates too
- detaro 9y ago
  I don't see how comments about current work trying to improve this are "insulting" anyone.
- dang 9y ago
  Comments like this are bannable offences and will eventually get your main account banned as well. If you have a substantive point to make, please make it thoughtfully; otherwise please don't comment until you do. We detached this subthread from https://news.ycombinator.com/item?id=14615504 https://news.ycombinator.com/item?id=14615504 and marked it off-topic.
majewsky 9y ago
Here I was, hoping for an innovative approach to render glyphs in OpenGL or Vulkan, but they're just dealing with accidental complexity of their platform, as Alan Kay would put it.
- deleted 9y ago
  [deleted]
- Scaevolus 9y ago
  Did you see this? http://pcwalton.github.io/blog/2017/02/14/pathfinder/ http://pcwalton.github.io/blog/2017/02/14/pathfinder/
OberstKrueger 9y ago
This post mentions how the text storage has already been moved to C++, and the possibility of moving parts of the rendering to C++ as well. Is this part of a trend for Atom to move at least key components to C++ and away from the web stack? Or am I off base with this thought and it's been lower-level to begin with, but these are just optimizations on that?
- wbobeirne 9y ago
  They seem to be adopting a more react native-like mindset of using React to orchestrate what should be happening, but have native code running lower level components. I wouldn't call it "moving away" from the web stack, just having it do more delegating, and less of the nitty-gritty.
- maxbrunsfeld 9y ago
  Atom has always had some C++ components, but lately we have moved more core data structures to C++. This PR, which re-implements the text-buffer in C++, also landed in the latest beta. https://github.com/atom/atom/pull/14435 https://github.com/atom/atom/pull/14435
  - pjmlp 9y ago
    With enough such improvements, Atom will become a native app, as it should always have been.
pugio 9y ago
I've maintained restrained excitement about Atom for years. A super hackable editor (what more could a tool-obsessed coder want)... but frustratingly laggy. This release finally feels snappy enough that I may switch. Large files, slowish startup, and the like are all special case problems that I can use Sublime for, but until now, the almost subliminal typing sluggishness always drove me away. Bravo Atom team for making it fast enough. I look forward to continued improvements in this space.
- nicpottier 9y ago
  You may also want to give VSCode a go. I haven't used a Microsoft product (willingly) for decades, but it is a really, really nice and much snappier than Atom in my experience with things like key echos. Their integration for TypeScript and GoLang are first class as well. Overall though I held the same excitement for Atom as you did (and I used to use Emacs for everything because I wanted an open editor in my tool belt) I've really come to appreciate the approach and polish of VSCode.
  - giancarlostoro 9y ago
    Also as a result of developing VS Code they've made HUGE improvements to Visual Studio 2017. If anyone had been programming .NET Core with VS 2015 and switched to VS 2017 you know what I'm talking about. I went from waiting 12 seconds for my project to compile to blinking and Chrome is opening up. Of course you have to turn off their browser debugging integration, that thing just sucks up so much dev time if you're not using it at all.
    - flukus 9y ago
      My experience with 2017 has been the polar opposite. It runs glacially slow compared to the 2013 installation on the same machine. The startup time makes eclipse look lean and mean, it takes over a minute to start.
      - Sacho 9y ago
jtokoph 9y ago
> But if we’re going so far as to bypass Chrome’s CSS engine, maybe we should try to bypass the DOM entirely. Seems like Atom will eventually just be a native app.
- djfm 9y ago
  Yeah, technology loves cycles. "Hey, let's write an editor for a browser. Oh wait, we need a browser for that editor". Something good will probably come out of this eventually. I mean if they manage to turn electron into a true native cross platform app framework it's nice.
  - kuschku 9y ago
    > I mean if they manage to turn electron into a true native cross platform app framework …then you’ll end up back where you started with the JVM.
    - djfm 9y ago
      Right. We might as well just compile our JS to Java. Instead of using web tech to build native apps I think we should focus on improving browsers so that web apps behave more like native apps and have the same capabilities. Browsers should be the cross-platform VM and webassembly is a good step in that direction.
- mrmondo 9y ago
  If it does, I'll reconsider using it. I truly can't stand JavaScript 'apps'.
andrewmcwatters 9y ago
Though I use Atom on a daily basis, I maintain the opinion that with software available such as Visual Studio Code, it's painfully obvious that Atom never had performance as a high priority to begin with.
linopolus 9y ago
ViM!
torrent-of-ions 9y ago
What a waste of time. A text editor where "more responsive typing" is a feature is a joke. These problems were solved decades ago on far more limited hardware.
dham 9y ago
I thought this was going to be a post about fixing the horrible font rendering. Although I guess that's really a Chromium issue. Still can't switch to Atom to this day because of the font rendering.
LorenzoLlamas 9y ago
Yet another post about "technology improvements" that basically is some company (Github) with an axe to grind that wants to reinvent the wheel but has nothing new to offer. To be more clear, no one is writhing in their sleep, or bemoaning to their team mates, this: "We have no good way to edit text in the 21st century". No one. At best, it's a nice idea to see "what if" we could build an emacs-like text editor using modern day web technologies, just to see what browsers and HTML5, etc, can do these days, and hey, maybe we will learn something and push the browser technology a bit, too. At worst, it's bunch of people with no other interesting ideas and who need to bring attention to their company. What's next for this Electron crowd? Let's see if we can build a whole operating system into a browser? Oh wait. That's also been done with a lot of noise and no real-world impact. Well then, what about a new kind of spreadsheet? Or maybe we could do some cool photo-processing using only a TI-84 calculator! Ugh. I'm so tired of this, and this massive post by the dev team at Atom proves the insanity of all this. They have spent thousands of man-hours "improving" their text editing rendering for their slow text editor (but hey, we saved time by building it on top of Chrome!), and yet they are nowhere near text-rendering speeds of 40 years ago. But never mind that. They will continue to plug ahead and write more posts about it. Meanwhile, emacs (and Vim) plug along as always. How bad is it (to me)? I'll tell you. Even though I alter between Sublime (written in real code and not on 'borrowed' code) and BBEdit sometimes, along with Vim (still learning), and even MacVim (the horrors!)... THIS is how bad it is. It's so bad... that I would use TextEdit to edit code before I used Atom. I promise you. I actually like TextEdit and often use it anyway. I sometimes wish Apple would just add a few tiny improvements (but I'm daydreaming) and I would use it for 90% of files and projects. But Atom? Like a lot of modern day projects (React, Bootstrap, WordPress, Facebook, etc), it's a total step backwards to reinvent what we already had. So that basically "new" people can come along and play - with less understanding, IMHO.
- johnfn 9y ago
  The fact that the only important factor you can think for a text editor to improve on is text rendering speed shows that you're not really on Atom's target demographic. You'd think that hundreds of thousands of Atom users would convince you that maybe there's something to the editor that works for others if not for you. But nope, all those guys are happy with switching their main IDE to "a total step backwards", for some reason.
deleted 9y ago
[deleted]
benibela 9y ago
Recently I had to edit test data for a grading platform (People upload their programs, the programs get called with the test data and they get feedback if their program works correctly). One test file had 900 000 characters in one line. Almost 1 MB, not a single linebreak. The grading platform is a webpage and you upload things through an online editor, so I pasted the file in Firefox and Firefox crashed.

154 points by podgib 9y ago

> One frustrating component of the above breakdown is the time spent recalculating styles. At this point, it looks like the only way to solve this within the current paradigm is to use CSS less and reduce the number of selectors in the application, but that’s going to be a hard fought battle given the huge number of themes in the ecosystem. This is a perfect example of why we need parallel restyling. :)

Xeoncross 9y ago
How would that work? Breakup the screen into chunks each CPU/GPU renders?
- pcwalton 9y ago
  The same way Servo (and the work-in-progress Servo port to Gecko) does it. Compute styles for every DOM node in parallel, using a work-stealing scheduler to distribute nodes among threads in a thread pool. Parent nodes must have their styles computed before children, but other than that constraint it's an embarrassingly parallel problem.
  - revelation 9y ago
    Work-stealing scheduler, thread pool? What is going on here? Have any of you seen the kind of stuff recent games draw in 16 ms? It's amazing! They sure as hell don't use a work-stealing scheduler in a thread pool for single vertices, though.
    - pcwalton 9y ago
      Games are at an advantage because they can do a lot of up-front processing. They can statically schedule their content based on knowledge of the hardware, and programmers can and do even tell the artists to tailor their content directly to the system. Conversely, on the Web, we can't do any of this: we have no idea what the content is going to be like until we receive it, and we have to handle specifications that were written without parallelism in mind. All of the decisions we make have to be dynamic rather than static, which is why work stealing is especially effective. Besides, vertices are a much simpler problem than CSS styling. CSS supports hundreds of properties, all of which are parsed and cascaded differently. You have properties that are inherited and properties that are noninherited. You have properties that depend on other properties: for example, any lengths might be specified in terms of ems, which means you have to have resolved the font size first. You have properties that result in completely different render trees, for example "display". You can't effectively throw stream processors like GPUs at the problem (believe me, I've tried). Could we do better? Sure. But every proposed replacement for CSS I've seen (e.g. Cassowary) has made the complexity problem worse. And most native styling solutions I've seen are usually just very slow implementations of CSS. Separating presentation and markup is just hard, no matter what.
      - teleclimber 9y ago
        > But every proposed replacement for CSS I've seen (e.g. Cassowary) has made the complexity problem worse. Hi, what other proposed replacements for CSS do you know about? I'm interested in seeing what problems they ran into. I need to go look at Cassowary again. IIRC it's a solver, so sometimes the layout won't be what you expected, and it's very hard to know what to change such that it does what you want.
        pcwalton 9y ago
        Cassowary was admittedly a bad example, because it's a layout algorithm rather than a style system. But I've seen folks suggest that we just replace CSS with TeX, for example. Using TeX would make this problem a lot worse, because styling TeX involves expanding textual macros. You would lose any possibility of parallelism, ever.
    - zubat 9y ago
      Or to put it in other words: browser technology is asked to do so much that they had to go invent a new language to keep up. So that they could serve ads. For us ordinary folks trying to write good applications that can be maintained by one person and scale reasonably well, there's justifiable reason to jump off this rollercoaster and work in a more humble environment with modest perf/safety tradeoffs and native code executables(e.g. Go, Basic, Pascal).
      - justinmk 9y ago
        The "so they could serve ads" meme is facile, reductionist, sophomoric. Actually, the fact that Google et al. were able to identify a profit function that could be optimized to fund the last 15 years of technology is an incredible achievement. In ~2000 it wasn't at all obvious that the internet could find a robust funding model. Where the funding comes from is practically irrelevant, specially if it is a feedback function (i.e., an economic phenomenon, not "phone the legislature to fund more research!!1"). New funding models are good, too, of course. But the tone of the anti-ad camp is asinine.
        zubat 9y ago
        A realpolitik view of tech only holds under the assumption that any new technology is good technology. It allows nothing to balance or sustainability, and I believe the trajectory of the Web is unsustainable and therefore fundamentally doomed despite its near-term wonders. The SV camp has said nothing to convince me otherwise.
        coldtea 9y ago
        >Where the funding comes from is practically irrelevant, specially if it is a feedback function (i.e., an economic phenomenon, not "phone the legislature to fund more research!!1"). I preper phoning the legislature -- more democratic and less private interests-driven.
    - Manishearth 9y ago
      Games are a completely different problem space. "styling" is a concept that games don't have; games don't deal with deciding which thing has which style at runtime. Browsers do, because they are just given CSS and have to handle the cascading and assigning of styles on their own.
      - revelation 9y ago
        Of course they do, modern games are a complex interaction of many different shaders operating on all levels of abstraction on many different classes of runtime data that they compose, renew and adapt many many times in 16 ms. Is the whole CSS debacle a particularly unlikely concept to yield anything close to a reasonable performing implementation? Sure, but that is because nobody has applied the pressure necessary. People won't play a game that doesn't consistently meet a 30 ms deadline but they seem to happily put up with 3 seconds to final render and call it "amazing".
        Manishearth 9y ago
        Shaders are a completely different thing from styling (cascading). GPUs work here because games fundamentally operate on a list-like datastructure (the display list), with little interdependence. Styling on the other hand operates on a tree like datastructure (the DOM), with lots of interdependence. Cascading isn't something games need at all, and if it was, it could be precomputed. THis can't be done in webpages.
        mianos 9y ago
        Game engines are pretty much completely sitting on complex tree structures. Way more than the DOM. The main reason the DOM all looks so tricky is it is a hack on a hack on a hack. A lot of game engines have been rewritten from scratch many times over.
        Manishearth 9y ago
        Yes, trees are involved in games too, but not at the level I'm talking about. You don't have analogues for tree-structure-based "selectors" and anything more than straightforward property inheritance (e.g. inheritance of transformations in a skeleton) in game engines. CSS is much more complex in this aspect. The DOM having lots of legacy issues is not the reason styling is slow. CSS is designed for a lot of flexibility and can't be precompiled, which is why it is slow to style.
    - Rusky 9y ago
      Games do, however, use job systems just like that for plenty of things that aren't single vertices.
  - thomasahle 9y ago
    In css sibling nodes can certainly affect the position of each other, but that might be ok. A harder problem will be siblings that "run in" to each other, and overlap in various ways.
    - pcwalton 9y ago
      I'm talking about styling, not layout.
panic 9y ago
I dunno, I'd say it's more an example of why CSS isn't the right abstraction for styles in a text editor…
- pcwalton 9y ago
  CSS is more powerful than anything that popular native text editors can do. As far as I'm aware, in native text editors, generally, style can't influence (block-direction) layout, and that's why they can get away with determining what's visible before restyling. Once you have styles that can influence layout, this dependency is reversed, so any native text editor will have to restyle off-screen lines just as a browser must. Is it worth restricting an editor to only styles that don't influence block layout? For example, should it be impossible for a theme to make comment lines taller or shorter? I don't know; it's a tradeoff between performance and flexibility. My feeling is that there's a lot more room to improve the implementation before we have to resort to reducing capabilities, but reasonable people can disagree.
  - kazinator 9y ago
    Should it be impossible for a theme to make comment lines taller or shorter? Of course not; everyting should be in the same damned monospaced font in a text editor for writing code.
    - capnrefsmmat 9y ago
      My Emacs Org-mode setup already has larger font (and taller lines) for headings, so this isn't too crazy. Not everything in a text editor is code; some of it is text.
    - aninhumer 9y ago
      Why does code need to be monospaced? I feel like the only reason we all do it is that it's always been done like that so it feels wrong not to. The only actual reason I can think of for it is alignment, and that seems like a minimal benefit really. Variable width text is generally considered easier to read, so why couldn't this also apply to code?
pjmlp 9y ago
This is a perfect example of why Atom should have been a native application to start with.
- aninhumer 9y ago
  Eh, I feel like the web platform as allowed it to be massively extensible in a much more convenient and familiar way than a lot of other editors. I tried it for a little bit and it felt like the "Sublime Text but more open and flexible" that I really wanted. If they can work out a way to improve performance without sacrificing too much of that, it would be great.
  - pjmlp 9y ago
    As an Emacs fan, not really.
    - foldr 9y ago
      This isn't about emacs. Atom is for people who want an alternative to Emacs. If you only need to know JS and CSS to write an extension, that vastly increases the pool of people who are able to write extensions.
      - LeoNatan25 9y ago
        That "pool" of people "able" to "write" "extensions" is exactly the people you don't want touching your text editor, or any software for that matter. Anyone that has a psychological barrier to take a look at a language that they are not familiar with, let alone a framework or an ecosystem, is not someone that I want being anywhere near the software I use. In an ideal world, I wouldn't want them to be anywhere near the web I visit either, but that is a lost cause.
        foldr 9y ago
        The quality of Atom extensions is good, so that's clearly not true. Also, you are going nuts with the scare quotes. I don't even see what point you are trying to make with those.
twhb 9y ago
Parallel restyling just kicks the can down the road, asking for free perf elsewhere because we still haven't made it fast. What we need is a low-level style interface - .style but for computed, not CSS-integrated, styles - and then to plug into that using CSS where appropriate, or custom JS where appropriate, or even framework JS. Let people control style selection in a real programming language and you've guaranteed that it can now be done in a way that's fast and suitable.
- pcwalton 9y ago
  I don't necessarily disagree, but I'd like to reassess where we are in terms of performance once Typed CSSOM is widely used. Using Typed CSSOM to adjust the "style" properties of individual elements is awfully close to doing what you describe: the difference is that matching and cascading still happens, but the semantics become much simpler if you're adjusting individual styles, and it's not clear to me that most of the overhead can't just be optimized away at that point.

rjzzleep 9y ago

So, we're sort of simulating offscreen drawing by using a virtual dom? I mean don't get me wrong it's sort of nice that they did this as it's the only thing they could have done to deal with the issues I wrote in my 2014 blog post, but that also means that with a lot of effort the web is now able to do what quickdraw could almost 20 years ago...

pcwalton 9y ago
You've always been able to query layout information about DOM nodes that are off screen. The virtual DOM is used for other reasons.
- rjzzleep 9y ago
  With all due respect, no it's not. This is exactly what people used to do to optimize drawing in intensive application. You only render the visible area. The entire post explains the supporting actions needed to accomplish this for the browser. Thats why at the end of the text they talk about exploring the use of the canvas. Here's an application from ~2000 https://www.macintoshrepository.org/2214-vncthing https://www.macintoshrepository.org/2214-vncthing The actual VNC canvas was offscreen and it would only frequently display the entire thing. Which made it for a long time more efficient than modern vnc clients. I think 2010 it was still better than any other VNC client on macosx. It's by far not an uncommon technique, it's just a pain to do when your target is markup, which is what this post is all about. Granted, it's more complex because a tile here is a chunk of markup rather than a piece of a pixmap, but still.
  - pcwalton 9y ago
    Your confusion (which is understandable) points to the reason why I dislike the word "render": it's extremely overloaded. Rendering as defined by QuickDraw (which you alluded to in your above comment) or the VNC client you linked to is really painting, which browsers only do for areas that are on screen or close to being on screen. Browsers have performed this optimization for decades. What Atom is referring to by "rendering" here seems to be applying styles to parts of lines. Styling is a higher level concept than vector graphics. Partial styling is something that browsers have wanted to be able to do for a while, but it's quite complex. I've never seen an implementation of partial styling in any UI library, and certainly not in QuickDraw or VNC, which have no CSS-like concept at all.

draw_down 9y ago

I still really wonder about the approach of using web tech for this editor. But I haven't tried it in a while so I will do that shortly. I have been wanting more Github integration in my editor recently, ever since I saw the Xcode demo.

noway421 9y ago
I'd think that the only text editor that web browser is competent to have is <textarea>

y_u_no_rust 9y ago

Seems like such a wasted effort due to technology choice

Anone33 9y ago

Then ship Servo. It's getting annoying seeing the Servo devs constantly patting themselves on the back about how smart you are and insulting other engines that are actually serving users.

matthewmacleod 9y ago
That’s unfair. It’s hardly “insulting” to talk about the benefits of a new approach. And as I understand it, Stylo will be shipping in Firefox this year.
- pcwalton 9y ago
  I can't reply to the above comment because it's dead (and no, I didn't flag it), but you can try parallel styling out by building Firefox Nightly with --enable-stylo and enabling the preference in about:config.
  - Manishearth 9y ago
    It should be a pref switch in the next nightly on 64 bit linux and windows, fwiw.
    - nstart 9y ago
      that's good to know. I'm actively keeping up with FF updates (stable) and it'll be good to try the nightly updates too
detaro 9y ago
I don't see how comments about current work trying to improve this are "insulting" anyone.
dang 9y ago
Comments like this are bannable offences and will eventually get your main account banned as well. If you have a substantive point to make, please make it thoughtfully; otherwise please don't comment until you do. We detached this subthread from https://news.ycombinator.com/item?id=14615504 https://news.ycombinator.com/item?id=14615504 and marked it off-topic.

majewsky 9y ago

Here I was, hoping for an innovative approach to render glyphs in OpenGL or Vulkan, but they're just dealing with accidental complexity of their platform, as Alan Kay would put it.

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Scaevolus 9y ago
Did you see this? http://pcwalton.github.io/blog/2017/02/14/pathfinder/ http://pcwalton.github.io/blog/2017/02/14/pathfinder/

OberstKrueger 9y ago

This post mentions how the text storage has already been moved to C++, and the possibility of moving parts of the rendering to C++ as well. Is this part of a trend for Atom to move at least key components to C++ and away from the web stack? Or am I off base with this thought and it's been lower-level to begin with, but these are just optimizations on that?

wbobeirne 9y ago
They seem to be adopting a more react native-like mindset of using React to orchestrate what should be happening, but have native code running lower level components. I wouldn't call it "moving away" from the web stack, just having it do more delegating, and less of the nitty-gritty.
maxbrunsfeld 9y ago
Atom has always had some C++ components, but lately we have moved more core data structures to C++. This PR, which re-implements the text-buffer in C++, also landed in the latest beta. https://github.com/atom/atom/pull/14435 https://github.com/atom/atom/pull/14435
- pjmlp 9y ago
  With enough such improvements, Atom will become a native app, as it should always have been.

pugio 9y ago

I've maintained restrained excitement about Atom for years. A super hackable editor (what more could a tool-obsessed coder want)... but frustratingly laggy. This release finally feels snappy enough that I may switch. Large files, slowish startup, and the like are all special case problems that I can use Sublime for, but until now, the almost subliminal typing sluggishness always drove me away. Bravo Atom team for making it fast enough. I look forward to continued improvements in this space.

nicpottier 9y ago
You may also want to give VSCode a go. I haven't used a Microsoft product (willingly) for decades, but it is a really, really nice and much snappier than Atom in my experience with things like key echos. Their integration for TypeScript and GoLang are first class as well. Overall though I held the same excitement for Atom as you did (and I used to use Emacs for everything because I wanted an open editor in my tool belt) I've really come to appreciate the approach and polish of VSCode.
- giancarlostoro 9y ago
  Also as a result of developing VS Code they've made HUGE improvements to Visual Studio 2017. If anyone had been programming .NET Core with VS 2015 and switched to VS 2017 you know what I'm talking about. I went from waiting 12 seconds for my project to compile to blinking and Chrome is opening up. Of course you have to turn off their browser debugging integration, that thing just sucks up so much dev time if you're not using it at all.
  - flukus 9y ago
    My experience with 2017 has been the polar opposite. It runs glacially slow compared to the 2013 installation on the same machine. The startup time makes eclipse look lean and mean, it takes over a minute to start.
    - Sacho 9y ago

jtokoph 9y ago

> But if we’re going so far as to bypass Chrome’s CSS engine, maybe we should try to bypass the DOM entirely. Seems like Atom will eventually just be a native app.

djfm 9y ago
Yeah, technology loves cycles. "Hey, let's write an editor for a browser. Oh wait, we need a browser for that editor". Something good will probably come out of this eventually. I mean if they manage to turn electron into a true native cross platform app framework it's nice.
- kuschku 9y ago
  > I mean if they manage to turn electron into a true native cross platform app framework …then you’ll end up back where you started with the JVM.
  - djfm 9y ago
    Right. We might as well just compile our JS to Java. Instead of using web tech to build native apps I think we should focus on improving browsers so that web apps behave more like native apps and have the same capabilities. Browsers should be the cross-platform VM and webassembly is a good step in that direction.
mrmondo 9y ago
If it does, I'll reconsider using it. I truly can't stand JavaScript 'apps'.

andrewmcwatters 9y ago

Though I use Atom on a daily basis, I maintain the opinion that with software available such as Visual Studio Code, it's painfully obvious that Atom never had performance as a high priority to begin with.

linopolus 9y ago

ViM!

torrent-of-ions 9y ago

What a waste of time. A text editor where "more responsive typing" is a feature is a joke. These problems were solved decades ago on far more limited hardware.

dham 9y ago

I thought this was going to be a post about fixing the horrible font rendering. Although I guess that's really a Chromium issue. Still can't switch to Atom to this day because of the font rendering.

LorenzoLlamas 9y ago

Yet another post about "technology improvements" that basically is some company (Github) with an axe to grind that wants to reinvent the wheel but has nothing new to offer. To be more clear, no one is writhing in their sleep, or bemoaning to their team mates, this: "We have no good way to edit text in the 21st century". No one. At best, it's a nice idea to see "what if" we could build an emacs-like text editor using modern day web technologies, just to see what browsers and HTML5, etc, can do these days, and hey, maybe we will learn something and push the browser technology a bit, too. At worst, it's bunch of people with no other interesting ideas and who need to bring attention to their company. What's next for this Electron crowd? Let's see if we can build a whole operating system into a browser? Oh wait. That's also been done with a lot of noise and no real-world impact. Well then, what about a new kind of spreadsheet? Or maybe we could do some cool photo-processing using only a TI-84 calculator! Ugh. I'm so tired of this, and this massive post by the dev team at Atom proves the insanity of all this. They have spent thousands of man-hours "improving" their text editing rendering for their slow text editor (but hey, we saved time by building it on top of Chrome!), and yet they are nowhere near text-rendering speeds of 40 years ago. But never mind that. They will continue to plug ahead and write more posts about it. Meanwhile, emacs (and Vim) plug along as always. How bad is it (to me)? I'll tell you. Even though I alter between Sublime (written in real code and not on 'borrowed' code) and BBEdit sometimes, along with Vim (still learning), and even MacVim (the horrors!)... THIS is how bad it is. It's so bad... that I would use TextEdit to edit code before I used Atom. I promise you. I actually like TextEdit and often use it anyway. I sometimes wish Apple would just add a few tiny improvements (but I'm daydreaming) and I would use it for 90% of files and projects. But Atom? Like a lot of modern day projects (React, Bootstrap, WordPress, Facebook, etc), it's a total step backwards to reinvent what we already had. So that basically "new" people can come along and play - with less understanding, IMHO.

johnfn 9y ago
The fact that the only important factor you can think for a text editor to improve on is text rendering speed shows that you're not really on Atom's target demographic. You'd think that hundreds of thousands of Atom users would convince you that maybe there's something to the editor that works for others if not for you. But nope, all those guys are happy with switching their main IDE to "a total step backwards", for some reason.

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benibela 9y ago

Recently I had to edit test data for a grading platform (People upload their programs, the programs get called with the test data and they get feedback if their program works correctly). One test file had 900 000 characters in one line. Almost 1 MB, not a single linebreak. The grading platform is a webpage and you upload things through an online editor, so I pasted the file in Firefox and Firefox crashed.