OS13k is a tiny operating system that fits in a 13 kb zip file.

It includes native support for Shadertoys, Dweets, ZzFX sounds, music, trophies, touch input, and much more.

• OS13k is a tiny web based pseudo OS and game engine designed for creative coding purposes
• The core of OS13k is around 10k zipped including all the system apps
• OS13k can connect with other JS13k games via local storage to add music and trophies
• Users can extend OS13k by addinng their own programs and shaders

• ZzFX sound effects with support for sound seeds
• ZzFXM music system, player, and visualizer
• Trophy system and viewer
• Centralized input system
• Custom user programs
• Dwitter, ShaderToy, and WebGL support
• GUI with window manger, taskbar, tray and settings
• Mobile/touch support

• OS13k stores it's list of programs in programs.js
• For fast iteration when developing, most recent active window is opened on startup

Add an icon config to programs.js to register your program, examples...

• [icon, src, width, height, flags, name, help, folder]
• ['?','help.html']
• ['✌️😄','system/systemTest.html',,,full|resize|code|sticky]
• ['🌊','dweets/underwaterCavern.dweet.js']
• ['☯','toys/infiniteYinYangs.shader.txt',500,500,full,'Put instructions here.']

• OS13k can open any html file and it will work the same as if opened directly
• Chrome is recommended, but Firefox is also supported
• Viewing OS13k locally may not work if it treats local files as cross-origin
• Prefix all local storage keys with OS13kYourProgramName to prevent collisions during JS13k (use at least 2 letters)
• When the reload button is clicked, OS13kReload is called if it exists instead of reloading the iframe
• For development we recommend VSCode with the Live Server Plugin
• You can also create a custom program to edit code directly in OS13k

• Trophies are perhaps the most important part of OS13k and have many uses
• Apps can register trophies for their games, the OS tracks which are unlocked
• To unlock trophies use OS13k.Trophy(icon, gameName, trophyName, message)
• You can pass in a value as the message, like a high score for example
• HTML tags and commas can not be used in trophy data
• When a new trophy is unlocked or the message is changed a popup will automatically appear
• Total trophy count is shown in the taskbar and the trophy case shows all unlocked trophies
• You can use tophies to store data! Use OS13k.GetTrophy to get a trophy message

• OS13k.Trophy(game='', icon='', name='', message='') - Unlock a trophy
• OS13k.GetTrophy(game, name) - Get most recent matching trophy, 0 if no trophy
• OS13k.Trophies() - Get full list of trophy objects

• ZzFx sounds are supported by default and several other audio functions are provided
• ZzFX is open source sound effect generator with an easy to use sound designer https://zzfx.3d2k.com/
• A seeded ZzFX sound player is available to save space with much smaller sound calls
• OS13k.PlaySeed(seed, lengthScale=1, volume=1, randomness=.05, frequency) - Play a zzfx sound from seed
• OS13k.PlaySamples(samples, sampleRate=44100) - Play audio samples
• OS13k.Note(semitoneOffset=0, rootNoteFrequency=440) - Get frequency of a note on a musical scale
• OS13k.Speak(text, language='en', stopSpeech, volume=1, rate=1, pitch=1) - Play speech of the text
• Seeds can also be strings (will be hashed) or full ZzFX sounds
• A custom gain node is created for every sound, use sound.gain.gain.value to change

• ZzFXM by Keith Clark is the music player
• OS13k.PlayMusic(song) - plays the song with zzfxm
• OS13k.GetAnalyser() - returns a 32x32 music analyser canvas
• OS13k.GetAnalyserData(i) - returns index into a 32 length array of frequency volumes normalized between 0-1
• OS13k.StringToMusic(string, validate) - Converts a string to a music array and checks if valid

• The OS13k object is set in your program after load, if you need it on load use parent.OS13k
• zzfx also becomes available after your program loads and can be called directly
• OS13k.CreateShader(canvas, shaderCode) - Create a shadertoy compatible webgl shader
• OS13k.RenderShader(canvas, shaderProgram, time=0, frame=0) - Render a shader
• OS13k.StripHTML(string) - Removes all HTML tags in a string
• OS13k.Hash(string) - Returns numeric hash code for a string
• OS13k.Popup(html, speak) - Shows a popup with html body and optional speech and sound

• OS13k.Random(max=1, min=0) - Get a seeded random value clamped between min and max
• OS13k.randomSeed - You must set the seed before calling OS13k.Random
• OS13k.Clamp(a, max=1, min=0) - Clamp value between max and min
• OS13k.Percent(v, a, b) - Get clamped percent between a and b
• OS13k.Lerp(p, a, b) - Lerp clamped percent between a and b

• Programs with the extension .dweet.js or .shader.txt or will automatically load as Dweets or Shadertoys!
• Dweets and Shadertoys are automatically paused when they don't have focus (after a 1 second warmup)
• They also automatically have the show code option by default unless explictly disabled
• Dweets can do anything that other programs can do including calling OS13k functions and ZzFX
• Dweets and Shadertoys are automatically paused when not focused (unless awake is set)
• Shaders support iTime, iFrame, iMouse, iResolution, and iChannel0
• iChannel0 is an image of the previous frame, this can be used to make effects or store game logic

• OS13k provides an easy to use input system to help eliminate redundant code
• Call OS13k.Input(window) to get the input object
• the object format is {x, y, keypress, keydown, mousex, mousey, mousepress, mousedown}
• x and y is a -1 to 1 direction from WASD or direction buttons
• mousex and mousey is the mouse position
• wheel is the mouse wheel delta
• keypress and mousepress are arrays, an element is 1 if that key is pressed
• keydown and mousedown are arrays, an element is 1 if that key is down
• See System/Test/InputTest for an example

• name - Display name (if absent will build nice name from camel case src filename)
• src - Source filename
• icon - Can contain html tags, fits about 2 emojis
• don't close html tags, they will automatically be closed
• width (720) and height (405) - Size of window (default is 16:9 aspect)
• help (optional) - Help message, shows an icon on the window's titlebar (try to keep it short)
• author (optional) - Name of creator
• sticky (0) - Will automatically open of program on restart if it was open
• reload (1) - Shows the reload option
• awake (1) - Prevents window dim and and pausing dweets/shaders when not focused
• full (1) - Enables full screen option
• code (0) - Shows code option, defaults to true for dweets/shaders, help is shown instead if it exists
• rezize (1) - Allows resizing the window
• shortcut (0) - Shows shortcut icon on the desktop

• You can create and access custom programs in the user programs folder
• User programs have the same capabilities as any other program!
• It auto detects HTML (starts with <), Shadertoy (has void mainImage), or Dweet
• This can be used to iterate on dweets or small shaders, or to load a full program.
• Drag and drop a file into the text box to load it
• The screenshot button is available for Dweets and Shadertoys
• User Dweets has loop protection to help prevent freeze ups, though it can still occur
• Press Alt Enter to reload when live edit is disabled
• User programs will not run until clicked to prevent executing bad code

• To add a trophy or music track, just save a special key to localStorage!
• The smallest way to add a single trophy (like for winning) is localStorage['OS13kTrophy,Icon,GameName'] = ''
• For more control use localStorage['OS13kTrophy,Icon,Game Name,Trophy Name'] = Message
• You can change the message to update the trophy, like a highscore for example
• Music works the same way, use localStorage['OS13kMusic,Song Name'] = JSON.stringify(song)
• OS13k automatically checks localStorage and display popups for new trophies and songs from other games
• This is possible because all JS13k games share the same local storage! Pretty cool right?
• You can test locally by pasting your trophy code into the OS13k's console app

Most of the OS was created by myself, but there were many other people helping out. Thank you to everyone for their efforts, I could not have done it alone!

• Keith Clark - ZzFXM
• Tomxor - Don't Fall
• Niklas Berg - Shedding Snake
• Pavel - Visualizer and 404
• Rodrigo Siqueira - Sticky Note
• Kang Seonghoon - Roadroller

Additional help by...

• Katkip, Jaburns, Xem, Rebecca König, Cantelope, DaSpider, Lionleaf, Yurume, Magna, Thomas Brierley, Nicholas Ortenzio, Yuanchuan, Jani Ylikangas, Martinn Kleppe, Erik Sombroek