OLC Codejam 2025

Our submission to the OLC CodeJam 2025, using the Odin Programming Language. This project is based on the Web Odin Template from Karl Zylinski (which he explains in this video), using Raylib.

The theme for this Jam was shapes.

You can play the game on itch.io.

Screenshots

Building

Run the specific files for your platform:

Windows Desktop: build_desktop.bat
Linux Desktop: build_desktop.sh
Windows Web: build_web.bat (you need Emscripten installed, add location to the script)
Linux Web: build_web.sh (you need Emscripten installed, add location to the script)

Note that for desktop, essentially just run the Odin Compiler:

odin build src/main_desktop -out:synth_shapes.exe

The executable needs to be next to the assets directory, so if you want to distribute the binaries, remember to copy it as well (this is what the script does).

Tested with the Odin Compiler version dev-2025-08-nightly and Emscripten 4.0.13.

How to use

The idea of this application is to create music using regular shapes. The dot moving through the figure is the beat, and each time it reaches a vertex, a sound will be played. Currently there are 3 instruments.

Also, if a figure is smaller, the beat will have to travel less distance, which means a faster pace.

In select mode (press 1 on your keyboard or the S button on the UI) you can:

Left click and drag to create new figures (note that if the figure is too small, it will be deleted). You can use the UI on the left to configure what properties they will have.
Left click on the circle on the center of the figure to select it. With the UI on the right, you will be able to modify its properties: point speed, music notes, the counter, number of sides of the figure, etc.
You can resize the figure by moving the small circle on one of the figure's vertices. This makes the beat faster or slower.
You can synchronize the beat with the rest of the sounds by clicking on the figure's sides. To reset the current cicle, use the button Reset beats.
Each figure will have a counter. When the beats completes one cicle, the counter gets decreased by one. When the counter is 0, no more sounds will be played.
Use Ctrl-D to duplicate the selection.
Holding Shift, you can select more, or use right click and drag to select figures in a rectangular fashion.
Use Delete or Backspace to delete the figures currently selected.
Left click elsewhere or press Esc to cancel the current selection.

The link mode (number 2 or the L button) will allow you to create links between the different figures to create longer sequences. When a figure's counter reaches 0, the linked figure will start playing.

To create a new link, left click to select the two figures.
You can only link to one figure, so re-linking a figure will overwrite the previous.
Double click a figure to remove its link (essentially, a link to itself).

Anytime, you can use Space to pause the simulation and the mouse wheel to move the camera around.

Code stats

---------------------------------------------------------------------
Language           files          blank        comment           code
---------------------------------------------------------------------
Odin                  10            476            485           1931
HTML                   1             13              1            100
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SUM:                  11            489            486           2031
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