7 ms·
A Raycaster in Bash
- Teongot 2y agoI'd love to see this combined with the author's fork()-less implementation of ps to make a (almost) fork()-free implementation of psDoom. Seriously though, this is really cool
- Arch-TK 2y agoIt's unfortunate that stty requires forking. Maybe the next project will be to use bash and rowhammer to call the necessary ioctls to do it without forking.
- markeroon 2y agoOnly 300 lines of code, impressive! I love this.
- einpoklum 2y agoAnd to think, that my own bash scripts spend 300 lines just parsing various command-line options, while instead I could be showing this game... :-P
- shric 2y agoBeautiful. Correct me if I'm wrong, but this looks like a bash version of https://lodev.org/cgtutor/raycasting.html https://lodev.org/cgtutor/raycasting.html Edit: ah, just noticed this is in the readme :(
- CaesarA 2y agoI wonder if texture mapping this would look good.
- Arch-TK 2y agoShe has been brainstorming how to handle texture mapping within the performance constraints of doing it in bash for a week now (long before she actually got this working) and so far we've come up with some hypothetical ideas but she has not tried any of them yet. Maybe tomorrow...
- corytheboyd 2y agoImagine a TUI where you need to navigate a literal maze of options
- Arch-TK 2y agoMany CLI programs which take option have already managed to do this (in the text-based adventure game style).
- krapp 2y agoThat's the kind of "futuristic interface" you'd see in a cyberpunk movie, and it would be incredibly annoying in real life.
- jaynetics 2y agoLike this one in Jurassic Park? https://youtu.be/URVS4H7vrdU https://youtu.be/URVS4H7vrdU Funnily enough, the slow rendering is kind of a plot device here.
- Arch-TK 2y agoThe program from that scene was not some crazy invention for the purpose of having an interesting computer scene. It is a real piece of software for silicon graphics workstations called fsn (File System Navigator). There's a x windows remake of it called fsv: https://fsv.sourceforge.net/ https://fsv.sourceforge.net/ And then there's this even cooler UI which takes this whole idea much further called eagle mode: https://eaglemode.sourceforge.net/ https://eaglemode.sourceforge.net/
- rzzzt 2y agopsDooM pits you against processes on the system represented as enemies: https://psdoom.sourceforge.net/ https://psdoom.sourceforge.net/
- alsetmusic 2y agoI had no idea this was possible with Bash. I’ve considered myself proficient with Bash at a pretty advanced level at times and this just blows me away. I don’t have the math chops to understand how it’s implemented, but it’s a pleasure to see.
- tdeck 2y agoIn case you wondered if there is a raycaster written in MS Batch: https://github.com/nTh0rn/batch-raycaster https://github.com/nTh0rn/batch-raycaster
- izabera 2y agoThat's really cool! The explanation on their blog is great!
- rpoisel 2y agoThanks for the hint! That's exactly what I was looking for as I have never looked into raycasting but having an interest in it. Direct Links: - https://nthorn.com/articles/batch_raycaster/ https://nthorn.com/articles/batch_raycaster/ (batch variant) - https://lodev.org/cgtutor/raycasting.html https://lodev.org/cgtutor/raycasting.html (general intro)
- jsheroes 2y ago[flagged]
- dang 2y agoPlease stop making accounts to break HN's rules with. It will eventually get your main account banned as well.
- purplesyringa 2y agoI love this. I've been wondering how the picture is drawn with less than one `echo` per pixel, and it's very clever: the game is "not really" 3D, so you can run raytracing just once per column, and then you only need to draw a couple of lines (for sky, grass, and the actual object) -- this is done by outputting the "draw this pixel and move down by one" string to the terminal as many times as necessary using string repetition. I've been considering working on a voxel render engine (not for Bash, but for another computationally limited environment). This is a treasure, I'm certain I'll find something useful here.
- JKCalhoun 2y agoThe VoxelCanvas.js file (in Javascript, obv.) might be interesting to you as well. Same (raycasting) idea: https://github.com/EngineersNeedArt/Mooncraft2000 https://github.com/EngineersNeedArt/Mooncraft2000
- 8n4vidtmkvmk 2y agoI never ceases to baffle me how we're still stuck with these mind bogglingly slow shells. Pure madness. I can maybe understand that some apps require all the vt100 weirdness or whatever, but probably 90% of apps just write to stdout and err. Surely we can blit some text to the screen a bit quicker and put the other 10% into some compat mode.
- PhilipRoman 2y agoShells are slow (particularly bash), sure, but I'm not sure how the rest of your comment follows from that. The shell is not involved in interpreting terminal escape sequences in any way, and modern terminals are quite fast - I can render animations in a 350-column terminal and they are as smooth as can be, given the constraints. Besides, the whole premise of this post is that bash is the wrong language for raycasting, kind of like writing bubblesort in CSS. >put the other 10% into some compat mode There is nothing preventing that, just test if the string contains sane characters only and use a fast path for that. The problem is that there is no actual fast path for software text rendering, you still need to process ligatures, etc.
- anfractuosity 2y agoVery cool! I'm curious when it says "did you know that accessing a random element in an array takes linear time", why that's the case, with bash?
- izabera 2y agonormal arrays in bash are implemented as linked lists. bash stores a pointer to the last accessed element, which turns the most common case of iteration into O(1), but the performance is terrible if you need to jump around see some basic benchmarks here https://gist.github.com/izabera/16a46ed79c2248349a1fb83844686df3 https://gist.github.com/izabera/16a46ed79c2248349a1fb8384468... there are also associative arrays which are bucketed hash tables, which are fine for string keys but imho they are hardly ever worth it as a replacement for indexed arrays
- anfractuosity 2y agoThanks a lot, that's very interesting re. it using linked lists, and nice benchmark!
- ormaaj 2y ago<3
- mmh0000 2y agoOf course, we need to give an honorable mention to the `awk` raycaster from 9 years ago. https://github.com/TheMozg/awk-raycaster/tree/master https://github.com/TheMozg/awk-raycaster/tree/master
- Arch-TK 2y agoCool Easter egg: https://github.com/TheMozg/awk-raycaster/blob/master/awkaster.awk#L521 https://github.com/TheMozg/awk-raycaster/blob/master/awkaste...
- mlconnor 2y agoWow, that’s an insane challenge. I can’t believe that’s even possible.
- armSixtyFour 2y agoSadly I can't get this working. It just throws up the view into a file called buffered for whatever reason and exits immediately :(
- izabera 2y agotry `bash game.bash 2>errors` and see the content of that file when the game exits
- 1vuio0pswjnm7 2y ago"bash is slow." That's in part why I do not use it for scripting. I do not use it for interactive use either. Some popular Linux distributions also avoid bash as a scripting shell.