# Jazz Jackrabbit 2 for Mac and Linux

Native Mac and Linux versions of Jazz Jackrabbit 2 1.24 (The Secret Files), built from the game's
decompiled code. They play just like the Windows game and can join online games with Windows
players.

> **You need** your own copy of the game's files, version 1.24. The GOG release works. On a Mac
> you need Apple silicon (M1 or later) and macOS 13 or newer. On Linux you need a 64-bit PC with
> Flatpak; SteamOS has it already, and other distributions can set it up at flathub.org/setup.
>
> **First launch on a Mac:** the app is not signed with an Apple developer ID, so macOS blocks it
> the first time. Right-click the app and choose Open. On macOS 15 and later, open it once, then
> go to System Settings, Privacy & Security and click Open Anyway.
>
> **Steam Deck:** start the game once from Desktop Mode to choose your game folder. After that
> it runs from Game Mode.

## Build 1.3.3
~ 7 November 2026

### Changed
- Linux: the app asks for fewer permissions.
- Linux: the software centre page now describes the game and lists the changes in each build.

### Fixed
- Switching between a window and full screen with Alt+Enter could close the game with a "Could
  not set video mode" message after the window had been resized a number of times.

## Build 1.3.2
~ 7 November 2026

### Changed
- Fair Size Online has been renamed **Competitive Online**. In online games it limits your view
  to 800x600 at most: never wider than 800 or taller than 600, whatever the shape of your window
  or screen. Once these builds can join Plus Only servers, each server's own maximum
  resolution will be respected, as it is for JJ2+ players, and this setting will not override it.
- The menus, the Display Guide, these notes and the readme have been rewritten to be clearer.
- Linux: the software centre page now describes the game and lists the changes in each build.
- Linux: the app has a new ID, net.digiex.jazz2decomp.v124. If you installed an earlier build,
  remove it with flatpak uninstall org.jazz2.port. To keep your settings and saved games, copy
  the folder ~/.var/app/org.jazz2.port to ~/.var/app/net.digiex.jazz2decomp.v124 before you
  start the new one.

### Fixed
- Competitive Online let a very tall or very wide window see far more than 800x600 (for example
  336x1140 or 1444x320). Every view is now cut to 800x600 at most.
- Switching between a window and full screen with Alt+Enter could close the game with a "Could
  not set video mode" message after the window had been resized a number of times.

## Build 1.3.1
~ 6 November 2026

### Fixed
- Mac: in full screen on a 60 Hz display, Smooth and Fastest Response ran at only about 30
  frames a second. Full screen now runs at the full refresh rate at 60, 59.94 and 50 Hz, and no
  longer drops to 40 fps for seconds at a time on 120 Hz displays.
- Mac: Even 70 ran at 40 to 50 frames a second on displays slower than 70 Hz. It now shows one
  frame per refresh, as the original game did on a 60 Hz monitor.
- Smooth juddered every few frames on displays slower than 70 Hz, on both Mac and Linux. Motion
  is now even at any refresh rate.
- Changing the frame rate during a game no longer causes a stutter.
- The picture no longer shakes while the game is paused in Smooth mode.

### New
- The F9 counter now shows the real frame rate, without the original's cap of 70, with the
  game's own update rate (always 70) above it.

### Changed
- Input lag is about half what it was in build 1.3: about 40 ms from key press to screen at
  60 Hz, down from 79 ms.

## Build 1.3
~ 6 November 2026

### New
- **Linux version**, as a Flatpak, with the same features as the Mac version. It installs on any
  Linux with Flatpak, including SteamOS. Press F11, or Back and Start together on a controller,
  to open the settings over the game.
- **Smooth**, the new default frame rate. The game still runs at its original 70 updates a
  second, but a new frame is drawn at every refresh of your display, with everything positioned
  between updates, so motion is even at 60 Hz, 120 Hz or any other rate. Even 70 and Fastest
  Response are still available in the Frame Rate menu.
- Much lower sound latency: effects now play about 17 ms after the event, down from 50 ms in
  build 1.2.
- The game now starts straight at the menu. To see the intro movies again, turn on Game, Play
  Intro Movies at Start.
- Game, Change Game Folder lets you pick a different folder for the game's files.

### Fixed
- Linux: hosting or joining an online game crashed. Linux, Mac and Windows players can now play
  together, hosting and joining.
- The game setup screen crashed after browsing the list of other levels and then going back to
  set up a Battle. (The original game has the same bug.)
- The game folder is now checked when you choose it: it must contain Anims.j2a, Data.j2d and at
  least one episode from version 1.24. A wrong folder or an older version is refused with a
  message saying why, and if the files later go missing you are asked for the folder again.
- Steam's Game Mode cannot show a folder picker, so the first start there now explains how to
  choose the folder from Desktop Mode.
- The settings overlay stays sharp with the Soft and Arcade CRT styles.
- Linux: the window shows the game's icon and name in the taskbar. Crash reports are saved to
  ~/.var/app/org.jazz2.port/config/Jazz2/Crash Reports; please include that file when reporting
  a crash.

## Build 1.2
~ 6 November 2026

### Fixed
- Some levels made for JJ2+ crashed while loading or at the start of play. Levels that need JJ2+
  itself still show the original game's error message, as they do on Windows.
- Crashes now save a report to ~/Library/Application Support/Jazz2/Crash Reports. Please include
  that file when reporting a crash.
- The title, loading and continue screens were cut off in wide views. They are now shown whole,
  at 4:3 with bars at the sides.
- A crash at the end of an online level, caused by a long network message arriving in pieces and
  overrunning a buffer in the original game's network code. Fixed for both hosting and joining.
- Picking a screen size could drop the game to a 320x240 view, for example just after switching
  to full screen.

### New
- A Help menu: **Display Guide** explains every View, Picture and Frame Rate setting, and
  **What's New** shows this list.
- The View, Picture and Frame Rate menus are now organised into groups with the recommended
  choice first, and hovering over an item shows what it does. Less common sizes are under View,
  Other Sizes.
- Frame rate **Automatic**: Even 70 on displays of 100 Hz or more, Fastest Response on 60 Hz
  ones. (Smooth on every display since build 1.3.)

### Changed
- Sound effects play about 50 ms after the event, down from about a quarter of a second.
- Input lag on 60 Hz displays is less than half what it was: frames no longer queue up.
- The window no longer drops to about 40 frames a second on some Macs.
- `⌘` `,` opens the display settings over the game, which is handy in full screen.
- Screen sizes are greyed out in the game's menus and cutscenes, where the size cannot change.
- Sound now plays at 44.1 kHz by default instead of 22 kHz. If you had already chosen a rate in
  the game's sound options, it is kept.
- The About box shows the build number, for example Version 1.24 (1.2).

## Build 1.1
~ 5 November 2026

### New
- The game is now drawn with Metal, so it scales cleanly to any window size or to full screen.
- Picture styles: Sharp Pixels, Soft, Smooth Edges and Arcade CRT, with optional scanlines and a
  whole-pixels mode with black bars.
- Higher resolutions: see more of the level, with views up to 1920x1080 instead of the original
  640x480. Fit to Screen picks a size close to the original; the zoom steps and fixed sizes are
  in the View menu.
- Fair Size Online limits your view in online games. (Renamed Competitive Online in build
  1.3.2, which limits it to 800x600 at most.)
- A menu bar for the display settings: View, Picture and Frame Rate. These replace the game's
  own video options.
- Frame rate options Even 70 and Fastest Response, and an FPS counter.
- A choice of layout for two-player split screen.
- In full screen the picture stays below the camera notch on MacBooks that have one.
- In wide views the menu graphics keep their proportions.

### Fixed
- Some JJ2+ battle levels crashed the game because they use flipped tiles, which the original
  game does not support. Those tiles are now shown unflipped.
- Changing the zoom from the game setup menu could crash the game.

## Build 1.0
~ 4 November 2026

- Jazz Jackrabbit 2 1.24 running natively on Apple silicon Macs.
- Single player, local split screen and online play, hosting and joining, with players on the
  original Windows version.
- Sound and music as in the original game.
- Xbox, PlayStation and Switch Pro controllers.
- Window or full screen: `⌥` `Return` or `⌘` `Ctrl` `F`. Full screen does not change your
  display's resolution.
- The first start asks where your game files are and remembers the folder.
