Lua Carousel

Devlog

• 4 versions in 3 months, but only minor changes
  January 16, 2026 by Kartik Agaram

  Since the last update in Sep there have been 4 new versions but with only minor changes: Wrapping lines are indicated in the code editor with little grey circles and grey hyphens. Scrollbars have some... Continue reading

  
• Programming on your device with your preferred language
  September 02, 2025 by Kartik Agaram

  2

  Lua Carousel is a free, open source, live-editable and trustworthy environment for writing small, throwaway Lua and LÖVE programs on computers or phones. Starting with this version, it comes bundled... Continue reading

  
• Lua Carousel: program on the device you have, with docs at your fingertips
  May 12, 2025 by Kartik Agaram

  1

  Ever since I published Lua Carousel 2 years ago as a lightweight programming environment for computers and mobile devices, I've taken pride in its stability. It has always tried to minimize change. Yo... Continue reading

  
• Pong Wars, MMO edition
  February 16, 2025 by Kartik Agaram

  This one is based on Pong Wars . -- Pong wars with more than 2 colors and ability to speed up simulation. local n = 20 -- px per square local v = 20 -- px/s ball velocity -- If v gets too big, collisi... Continue reading

  
• New version after 41 days, and stop-motion animation
  February 15, 2025 by Kartik Agaram

  Today's version has some minor bugfixes and API changes. Here's a list of key changes in the repository: https://git.sr.ht/~akkartik/carousel2.love/commit/d88c57e https://git.sr.ht/~akkartik/carousel2... Continue reading

  
• Drawing with a pen on a pendulum
  January 11, 2025 by Kartik Agaram

  1

  The kids have been playing with a pen on a pendulum, and I started wanting to tweak the friction on it. -- We have a surface we view through a viewport. -- The surface has the same dimensions as the v... Continue reading

  
• New version after 16 days
  January 04, 2025 by Kartik Agaram

  1

  This version is mostly cleaning up and tightening the radical rewrite of the previous version. There's one major bugfix: searching for text using ctrl+f now works again. (This is inaccessible in commo... Continue reading

  
• New version after 9 days
  December 19, 2024 by Kartik Agaram

  1

  Absolutely no new features in this version, but the internals are radically rewritten. Nitty-gritty details are in this blog post from July. The new core has been in use for a while now and seems stab... Continue reading

  
• New version after 3 days
  November 17, 2024 by Kartik Agaram

  1

  The bad news is the previous version only lasted 3 days. The good news is Origedit had a couple more good suggestions which have made this version better: On narrow screens the overflow menu now space... Continue reading

  
• New version after 40 days
  November 14, 2024 by Kartik Agaram

  1

  Today's version has 5 minor bugfixes. The repository has the details. But the major quality of life improvement that merits a new version: the code editor spreads out over the whole screen width on ph... Continue reading

  
• Turn your phone or tablet into a chess clock
  November 01, 2024 by Kartik Agaram

  3

  Playing chess with the kids today, we finally started to feel the need to impose some sort of time constraint on moves. That got me to rustle up this quick program: Start_time = 12 -- seconds Curr_col... Continue reading

  
• Guest program: bouncing balls
  October 15, 2024 by Kartik Agaram

  1

  I just received a very fun program from Origedit . Enjoy! g=love.graphics rnd=math.random bs={} bs.gravity=10 function addb() local function dir() return (rnd()*2-1)*200 end table.insert(bs,{ x=rnd()*... Continue reading

  
• New version after 3 months, and turtle graphics
  October 05, 2024 by Kartik Agaram

  This version may matter a lot to some people. I massively sped up `print` calls in Carousel. So if you are in the habit of printing a lot to the lower half of the screen, you'll want this. Someone ask... Continue reading

  
• Interactively zooming in to the Mandelbrot set on a touchscreen
  September 16, 2024 by Kartik Agaram

  4

  ( Longer video ) I've implemented the Mandelbrot set a few times, but this was still surprisingly delightful. A basic version of the mandelbrot set is just 20 lines: function mandelbrot(x0, y0, w, n)... Continue reading

  
• A little timer app
  September 15, 2024 by Kartik Agaram

  2

  A friend was looking for a timer app, and I took the opportunity to also package up my little helper for managing GUI widgets that I've shown before ( 1 , 2 , 3 ). I also added support for long-press,... Continue reading

  
• New version after 4 months
  June 28, 2024 by Kartik Agaram

  1

  Nothing particularly new here, just a dozen or so fairly minor tweaks and bugfixes. Perhaps the most noticeable one is that I swapped the position of the copy and paste buttons in the menu. I found my... Continue reading

  
• Visualizing the digits of π
  May 04, 2024 by Kartik Agaram

  3

  The following program lets you scrub the mouse downward to find more and more precise approximations of π within the red optical sight in the center of the screen. N = 100 -- spacing between zoom lev... Continue reading

  
• A little recursion problem
  April 15, 2024 by Kartik Agaram

  2

  Are you reading this on your phone? Quick, see if you can solve this problem without getting up and switching devices. Convolving a list with itself. Given a list [x 1 , x 2 , ..., x n−1 , x n ], wh... Continue reading
• Drawing histograms
  April 03, 2024 by Kartik Agaram

  1

  When I last showed how one might draw lots of different kinds of charts in Lua Carousel , I mentioned that histograms were still an open question. I think I have a reasonable way now to work in suppor... Continue reading

  
• The simplest possible dither
  March 30, 2024 by Kartik Agaram

  2

  I saw this exchange yesterday: "Is there a trick for doing dithering that is so simple you can tell it to me in 500 chars and I will instantly memorize it and then never have to look it up again?" "Ad... Continue reading

  
• All the 1-D cellular automata
  March 23, 2024 by Kartik Agaram

  2

  Here's every possible rule for a one-dimensional (neighborhood-1) cellular automaton. All on a single infinite surface you can pan and zoom around on your touchscreen device. In 100 lines. T = 100 --... Continue reading

  
• A Sokoban client based on Lua Carousel
  March 11, 2024 by Kartik Agaram

  The kids have been enjoying Baba is You , and watching them brought back pleasant memories for me of playing Sokoban. So I went looking and found a very nice project that has collected 300 classic pub... Continue reading

  
• Lots of charts
  February 23, 2024 by Kartik Agaram

  First things first: I've uploaded a new version with some minor ergonomic improvements for non-mobile devices: some of the menu buttons now have keyboard shortcuts. They were noticeably more difficult... Continue reading

  
• A little programming game
  February 21, 2024 by Kartik Agaram

  The kids recently got a little paper computer and, perhaps ill-advisedly, I've been building it on my touchscreen computer. The way I rationalize it is, the paper computer gives no feedback on whether... Continue reading

  
• New version after 51 days
  February 16, 2024 by Kartik Agaram

  2

  I just published a new version with a few changes. Firstly, an incompatibility: creating an editor now requires a font, where it used to implicitly use the current font. I'm fixing one previous Devlog... Continue reading

  
• Pong Wars
  January 30, 2024 by Kartik Agaram

  3

  Two seconds into a video of this little game , I just knew I had to build it for myself. local n = 20 -- px per square local v = 200 -- ball velocity in px/s -- initialize a w*h board randomly with on... Continue reading

  
• A little game integrated with its tools
  January 19, 2024 by Kartik Agaram

  A week ago, my son (hearing that I was at loose ends) asked for "a game where you drag the player around the screen". This set some wheels in motion inside my head, resulting in this 3-screen app: one... Continue reading

  
• A sprite editor in 100 lines of code
  January 14, 2024 by Kartik Agaram

  1

  Recently I've been mulling ways to add images to my Lua Carousel scripts. One problem with LÖVE apps on mobile devices is a paucity of ways to get non-text data in and out. We don't have https suppor... Continue reading

  
• Some squishy balls
  January 03, 2024 by Kartik Agaram

  1

  Last night I encountered the work of Karsten Schmidt , and was inspired to reimplement a tiny part of the merest superficial sample of his huge project . It doesn't actually implement any flocking dyn... Continue reading

  
• Building an equation plotter
  December 27, 2023 by Kartik Agaram

  4

  New version with just a couple of minor tweaks: I wasn't calling car.mousemoved (akin to love.mousemoved ). Now I am. Fixed a crash due to UTF-8 in just the right place in the editor. This was somethi... Continue reading

  
• One finger to pan, two fingers to zoom
  December 23, 2023 by Kartik Agaram

  2

  Today I'm learning to implement some gestures we take for granted on mobile devices. v ={x=0, y=0, w=Safe_width, h=Safe_height, zoom=1.0} -- viewport f,s = nil -- ids of first and second touches start... Continue reading

  
• The Lua Carousel "productivity suite"
  December 20, 2023 by Kartik Agaram

  2

  Another new version of Lua Carousel today. Not because of any new bugs or features, but a few small changes to Carousel's primitives as I try to use them in scripts. In particular, I've included the l... Continue reading

  
• A voice recorder in 150 lines of code (well, kinda)
  December 18, 2023 by Kartik Agaram

  (Update: This post will no longer work as-is with the most recent version of Carousel. You no longer need to include the wav library. Also delete the function `save_wav` below, which is now bundled wi... Continue reading

  
• New version after 9 days
  December 17, 2023 by Kartik Agaram

  2

  The good news is the last version lasted 9 days. The bad news is carousel-az-safe.love was catastrophically broken for all 9 of those days. So much for "safe" :( I'm going to try harder to use both ve... Continue reading

  
• Conway's Game of Life with colors
  December 16, 2023 by Kartik Agaram

  1

  When I first started messing with LÖVE, one of the first examples I gravitated towards was this Game of Life with colors . I just went back to it and ported it to Lua Carousel. Very fun. In the proce... Continue reading

  
• Conway's Game of Life
  December 15, 2023 by Kartik Agaram

  Perhaps my favorite program. curr, new = {}, {} for x=1,Safe_width do table.insert(curr, {}) table.insert(new, {}) for y=1,Safe_height do table.insert(curr[x], 0) table.insert(new[x], 0) end end -- R... Continue reading
• Handling cascading collisions
  December 12, 2023 by Kartik Agaram

  Today I finally managed to wrap my head around a program I'd been struggling with for a few weeks: moving more than one block in response to collisions. -- each rect is of the form: -- pos={x=..., y=... Continue reading

  
• Pushing objects around in a dozen lines of code
  December 11, 2023 by Kartik Agaram

  1

  I've been playing around with detecting and responding to collisions, just with simple rectangles. Here's today's example, with lots of help from the LÖVE Discord that pointed me to the batteries lib... Continue reading

  
• Playing with LÖVE's physics engine for the first time
  December 09, 2023 by Kartik Agaram

  2

  I thought I'd make sure today that Lua Carousel correctly handles LÖVE's physics libraries. No issues! And then my son suggested I could turn the example in the LÖVE tutorial into a very simple game... Continue reading

  
• 2 days, um no, 0 days since last bug
  December 07, 2023 by Kartik Agaram

  My goal with Lua Carousel like with my other recent projects is to get to a point of zero updates. I want to get to an artifact that is runnable forever. My choices of Lua and LÖVE are driven by this... Continue reading

  
• Version ax: slightly improved menu behavior
  December 05, 2023 by Kartik Agaram

  Lua Carousel has two menus. Both now close more reliably when you tap outside them... Continue reading
• Version av: one bugfix, support for LÖVE 11.5
  December 04, 2023 by Kartik Agaram

  All of yesterday's changes included a new bug: touches sometimes moved the scrollbar when they shouldn't. You can read all about the gory details at https://git.sr.ht/~akkartik/carousel.love/commit/42... Continue reading

  
• Version as: major improvements to the scrollbar
  December 03, 2023 by Kartik Agaram

  Taps near the top of the editor sometimes failed to move the cursor. It turns out this was only happening soon after a drag of the scrollbar. Lua Carousel's scrollbar has always felt a little jumpy. I... Continue reading
• Version aq: mouse wheel support
  December 02, 2023 by Kartik Agaram

  I've been focusing so much on the mobile/touchscreen experience that I forgot to wire up the mouse wheel. This omission is now fixed, along with a minor bugfix and a few more abbreviations (example 7)... Continue reading

  
• Version ap: a lot less jittery
  December 02, 2023 by Kartik Agaram

  1

  No new features, only fixes for bugs. From most to least embarrassing: * If you selected some text and then hit the 'clear' button the app would crash. * Dragging the mouse/finger around on top of the... Continue reading
• Version ao: saving your programs across restarts
  November 26, 2023 by Kartik Agaram

  1

  This feature was very difficult. Lua Carousel launched without the ability to save to and load from files because I struggled to juggle two constraints: Reliability. I spent a long time trying to make... Continue reading
• Version aj
  November 25, 2023 by Kartik Agaram

  Just minor bugfixes since the previous update. In particular, opening one menu hides the other... Continue reading
• Version ag
  November 25, 2023 by Kartik Agaram

  Some improvements to the settings menu. Embarrassingly, you could operate the sliders even when the menu was collapsed... Continue reading
• Version af
  November 25, 2023 by Kartik Agaram

  1

  Fixed 2 catastrophic bugs if the window gets too narrow when resizing or updating fonts. Carousel should now throw an error if the window is too small. If you then grow the window and press a key it w... Continue reading
• Version ad
  November 24, 2023 by Kartik Agaram

  Lua Carousel's biggest limitation is its inability to save code across restarts. I can't yet come up with a good, simple UI for selecting filenames that supports small devices and also autosaves. One... Continue reading
• Safe versions
  November 23, 2023 by Kartik Agaram

  I just uploaded carousel-ac-safe.love. The other ac is preferable, but use this as a backup if the other one gives you errors. Lua Carousel has lots of unit tests for the editor it uses. But the tests... Continue reading
• Version ac
  November 23, 2023 by Kartik Agaram

  You can now select smaller font sizes, all the way down to 12px... Continue reading