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WebAssembly from Scratch: From FizzBuzz to DooM
- recursivedoubts 5y agoI can't tell if the lack of strings and DOM API interop in web assembly is on purpose or not. If it is on purpose, what an absolutely diabolical way to ensure javascript language dominance in the browser: give people a way to port their language to the browser, but make it incredibly difficult to do anything.
- skitter 5y agoAfaik for the WebAssembly MVP, the goal was to have a simple, efficient compile target - therefore only integers and floats. To make wasm more useful & easier to integrate, the plan calls for interface types[0], which allow both accessing complex (JS) objects and calling browser APIs. [0] https://github.com/WebAssembly/interface-types/blob/master/proposals/interface-types/Explainer.md https://github.com/WebAssembly/interface-types/blob/master/p...
- recursivedoubts 5y agointeresting, thank you
- runnerup 5y agothank you
- franz899 5y agoWebAssembly's purpose was never to replace JavaScript but only to speed up certain parts of a website/app.
- recursivedoubts 5y agothat's not how I remember it: https://brendaneich.com/2015/06/from-asm-js-to-webassembly/ https://brendaneich.com/2015/06/from-asm-js-to-webassembly/ edit: from the linked article, in case it isn't clear, an HN comment by eich: "Sure, in userland many languages compile to assembly. Hmm, where have I heard that word lately?"[1] [1] - https://news.ycombinator.com/item?id=9554914 https://news.ycombinator.com/item?id=9554914
- pjmlp 5y agoThat was the original message used to sell WebAssembly, however when the real goal is to replace ActiveX, Flash, Silverlight and PNaCL it was obvious that it would grew beyond that.
- cubano 5y agoreally? i thought it's purpose was to take us back to the good old days of sellable proprietary binary blobs instead of the more open HTML/JS/CSS stack.
- Deukhoofd 5y agoThe lack of strings makes sense, as many different languages and standard libraries have their own implementations of it, that can behave slightly differently. It now puts the implementation of the string to the compilers/linkers, as is generally the case for assembly as well. The lack of a DOM API is something I sorely miss as well. It's currently possible (and not that hard, you can just interact with JS), but comes with such performance overhead that you lose the entire benefit of WASM.
- flohofwoe 5y agoWhat type of strings though? Exposing Javascript string objects in WASM doesn't make much sense if the code is expecting C strings for instance. Same for other languages, those all have their own incompatible internal representations for strings. The only somewhat interop-friendly string type is a zero-terminated bag of bytes, usually UTF-8 encoded (aka C strings), but that's a different string representation than Javascript uses. The Emscripten SDK offers helper functions to marshal high level data types like Javascript strings to UTF-8 encoded C strings on the WASM heap and back to JS, so it's not that bad. DOM access can be achieved with helper libraries which call out into JS. And since any sort of DOM manipulation is extremely slow anyway there's not much of a performance difference even with the overhead of calling out from WASM into JS (which actually is quite fast nowadays).
- mamcx 5y ago>What type of strings though? The good one! UTf-8, NOT null terminated, pascal like. ie: what rust have: https://doc.rust-lang.org/std/string/struct.String.html https://doc.rust-lang.org/std/string/struct.String.html REPEAT the mistakes of C (and considering the security angle! in a browser!) must be a big no.
- masklinn 5y ago> UTf-8, NOT null terminated, pascal like. > > ie: what rust have: > > https://doc.rust-lang.org/std/string/struct.String.html https://doc.rust-lang.org/std/string/struct.String.html Rust (or C++) strings are not pascal strings. In pascal strings, the "string buffer" also contains the length information, and historically it was all bytes with a length byte at the start, which was why your strings started at index 1 and limited to 254 bytes. It's possible to modernise this style of strings to be less crummy (that is essentially what sds does), but C++/Rust string are a third take where the length (and capacity) are stored separately from the string buffer, and that buffer is always on the other side of a pointer (ignoring SSO, which Rust sadly doesn't have due to the original interface definition).
- pjmlp 5y agoUnfortunely that is not what WASM designers decided when they went without memory tagging for linear memory segments. So you get all the fun to corrupt linear memory C style.
- TazeTSchnitzel 5y agoThe difficulty is inherent; C, C++ and so on live in a very different world to JavaScript. Whether or not WebAssembly had direct interaction with JavaScript objects at launch or not, writing bridging code would still be tedious. But there's no reason you must write this yourself. Others have done the hard work for you and written libraries.
- HideousKojima 5y agoIt's also still missing proper garbage collection, meaning languages like C# have to include basically the entire runtime if you compile to WebAssembly. This is a major part of why Blazor apps in .NET 5 are ~2MB for a simple "Hello World" (closer to 8MB if you use the AOT compilation options in the .NET 6 preview).
- Deukhoofd 5y agoWhy would WASM have garbage collection? It's an assembly target, not a runtime. What if languages would want different memory management strategies? I know it's an existing proposal for WASM, but it feels so massively out of scope. If the issue is having to include runtimes in the WASM binary it might be more useful to think about how we could serve runtimes in a more efficient way.
- staticassertion 5y agoI feel the same way. I find it very odd that GC is something that WASM ever intends to think about. If shipping your entire runtime sucks, find a smaller runtime?
- steveklabnik 5y agoThink of it more of "integration with a host environment's runtime" than a "adding a runtime to wasm directly." (At least, that's what it used to be; I haven't been involved in WebAssembly for a long time.)
- pjmlp 5y agoThe problem is that each runtime has different GC requirements, so at best it will mean WASM GC semantics will be the underlying JS GC semantics, probably not what you want for a D or .NET GC, for example.
- steveklabnik 5y ago
- jollybean 5y agoWASM is supposed to be 'assembly' level a little bit like java bytecodes. So it's lower level than 'strings'. But as you have pointed out, the missing layer on top i.e. the 'thing we can practically use' is a big gaping hole and it's a little bit diabolical. The fact that JS has gotten so much faster and the lack of both higher-level abstractions and notably a really good 'bridge' to JS means it's lagged in terms of material applicability.
- milliams 5y agoI found this video https://www.youtube.com/watch?v=r-A78RgMhZU https://www.youtube.com/watch?v=r-A78RgMhZU "A Talk Near the Future of Python (a.k.a., Dave live-codes a WebAssembly Interpreter)" to be a brilliant introduction to WASM as well as writing interpreters in general. I'm a relative novice in the subject and it was pitched right at my level.
- Quekid5 5y agoDave Beazley is a truly amazing presenter. Another favorite of his of mine is his epic tale of how he ended up demolishing an opposing side's case in a civil lawsuit... by sheer luck of having a Python interpreter avaialable. For for you viewing pleasure: https://www.youtube.com/watch?v=RZ4Sn-Y7AP8
- 1vuio0pswjnm7 5y agoI learned about this author from SWIG. I have always liked that project. https://en.wikipedia.org/wiki/SWIG https://en.wikipedia.org/wiki/SWIG
- jgrahamc 5y agoIf you'd like to try (multiplayer) Doom in WASM there's https://silentspacemarine.com/ https://silentspacemarine.com/
- pjmlp 5y agoAn old port for PNaCL is available here, https://doom.pdox.net https://doom.pdox.net.
- iGu35 5y agohttps://www.google.com https://www.google.com
- Jnr 5y agoInteresting that Firefox by default did not render the fizzbuzz demo correctly by default. I had to click the canvas icon next to address bar and allow the canvas usage. And it did not show a prompt either. It just looked broken by default. Screenshot from Firefox vs Chrome https://i.imgur.com/Af8nTim.png https://i.imgur.com/Af8nTim.png
- fouc 5y agoFF 89 worked fine here (mac), either your FF version is old or it's some sort of FF/linux issue ?
- smichel17 5y ago...Good! The "prompt" permission model is fundamentally broken, because all it does is train you to click through the prompt. The "click the blocking button and turn it off" model is much better. It still trains you to turn off blocking when something is broken. However, crucially, that's only when it's broken. When it's not broken, you just use the site, instead of habitually clicking through the permission prompt that's just harvesting data, not actually needed to function. And yes, malicious sites can of course display themselves as falsely broken until you grant the permissions. But this makes them more annoying to use, granting a UX edge to the honest sites which don't request unnecessary permissions. In other words, the incentives of sites and users are more aligned.
- singularity2001 5y ago>>> all it does is train you to click through the prompt. no, if I want extra functionality, I click it, otherwise I ignore it. (random page wants my location? nah) modular blocking prompts were broken, optional prompts are fine
- dimes 5y agoYou probably have resist fingerprinting turned on
- Jnr 5y ago
- vitiral 5y agoThis is exactly the kind of tutorial I've been waiting for for years. The way blocks and breaks work is especially non-intuitive if you are used to either assembly or regular languages, and you START with it. Good work, really loving this tutorial!
- xcambar 5y agoJumping from FizzBuzz to Doom is quite the leap! It reminded me of the meme "howbro draw an owl": 1. Draw 2 circles 2. Draw the rest of the f**ing owl
- sharikone 5y agoJust a point for the first chapters: you are not required to run your own local server (even if things push in that direction) You can include the wasm as an ArrayBuffer or as a base64 encoded string and hardcode it in the javascript. Now it will run even in a static html.
- deleted 5y ago[deleted]
- jjice 5y agoIt's incredible how far the web has come. I remember the first time I saw a browser GameBoy emulator and I was amazed. Maybe I should port my GB emulator to WASM...
- sigg3 5y ago> It's incredible how far the web has come. I agree and disagree. It seems like no one is questioning why we need to use legacy web browsers in between all the code we're executing locally. It's like a new iteration of old tech like lisp machines, which started out as specific purpose only to grow into complete environments (afaik). In this regard, we haven't come far, it's just the syntax that has changed.
- lisper 5y agoIn the case of WASM, even the syntax hasn't changed, it has just come full-circle back to S-expressions.
- paulgb 5y agoFor one thing, I’m unlikely to download a native copy of Doom to run on my own machine from a strange website. The ability to run cross-platform code that uses my GPU in a secure sandbox is pretty neat to me.
- anthk 5y agoprboom-plus is open source, FFS. Also, you have FreeDoom.
- devwastaken 5y agoVery nice. I like these tutorials showing the nuts and bolts of wasm and C without just throwing it at emscripten toolchain. I'm curious if there's perf differences between canvas and webgl canvas. This project uses just canvas, but iirc passing frames to be rendered by webgl is faster. Perhaps I'm wrong in this context. I also don't see threading in here. Makes sense for a demo, but if this were to be used performantly you'd have to throw it all in a webworker so it doesn't block the main thread. This is one point of contention with wasm because it's not straightforward to render to a canvas/webgl on the main thread from a worker thread. OffscreenCanvas is one workaround but not supported by FF or safari.
- djhworld 5y agoThere's also the problem of getting keyboard input in and out of the web worker in a performant manner. I tried this a few years ago with a Gameboy emulator I had ported from Go to webassembly and used web workers to run the emulator in. Getting the keyboard input in, in a performant way was a real struggle using postMessage, although I'll admit I'm not the best at web programming so someone more skilled might have been able to do it better
- asiachick 5y agoYou could pass it via a SharedArrayBuffer
- plopz 5y agoFrom what I found on MDN "a side effect to the block in one agent will eventually become visible in the other agent", what does the word eventually mean there, what's going on under the hood?
- Dylan16807 5y agoShould just be nanoseconds. I think they're mostly making considerations for unfortunate thread scheduling where one gets stuck for a while.
- AlecMurphy 5y agoNice read! I ported DOOM to TempleOS about a week ago. https://git.checksum.fail/alec/chocolate-doom https://git.checksum.fail/alec/chocolate-doom
- bilg21 5y agoDoing the gods work, or the devil's work. I'm a little confused here.
- Mizza 5y agoI love seeing this kind of tutorial, that isn't just a step-by-step guide, but also an exploration of the thought process and trial-and-error that goes on in crafting each step, so thanks for sharing. Looks like a lot of the work on the Doom port (https://github.com/diekmann/wasm-fizzbuzz/tree/main/doom https://github.com/diekmann/wasm-fizzbuzz/tree/main/doom) is about getting common functions from the C standard library to work in WASM. Surely this seems like a good opportunity for a new Free Software initiative - something optimized, properly licensed/credited and easy for everybody to use?
- ronsor 5y agoThere's already wasi-libc: https://github.com/WebAssembly/wasi-libc https://github.com/WebAssembly/wasi-libc
- jnwatson 5y agoMy first question I thought of before reading this was how to actually display characters out of it. Quite a mess, IMHO. (Not that I'm blaming the author).
- innocenat 5y agoThis is common for lower-level API though. Displaying a single cube in modern OpenGL or Vulkan is also surprisingly a mess.
- innocenat 5y agoWhile I think this is nice, the tutorial is almost entirely unreadable on mobile.
- leeoniya 5y agosorry if the answer is to read the whole series (i only read part 4), but is there a comparison of this hand-optimized route vs what emscripten outputs (in terms of binary size an browser perf)? i assume a proper emscripten comparison would also need to strip networking & audio output.
- abledon 5y agoanother tutorial added to my bookmarks I will struggle to get around to :)
- hoten 5y agoCould I buy the author some headphones, I'd really like to see how they would port audio :) note on controls: 'ctrl' is a bad choice because ctrl + up/down on mac map to window management shortcuts, making the game unplayable.
- pests 5y ago"Then, I threw out everything which is either not needed or looks complicated. We only need the string formatting functions anyway, let's remove everything else. Th result is a crossover of musl 1.2.2 and arch from emscripten for musl 1.1.15. YOLO!" Lmao