I'm on Windows and GCS doesn't start! How come?

The most likely cause is not having OpenGL 3.2 or better installed on your machine. If you are on an older machine without the necessary OpenGL support, you may be able to work around this by putting the OpenGL32.dll from Mesa into the same directory as your GCS.exe file.

The second most likely cause is that you managed to get a copy of GCS running in the background without any visible windows. You can check for this by opening the Task Manager and looking for GCS in the list of running applications. If you find it, you can end the task and try starting GCS again. Defective input device drivers installed on Windows machines can cause this behavior. If GCS takes more than a second or two to bring up its initial window when you're certain there are no other copies of it running, you likely have one of these bad drivers installed. There is nothing GCS itself can do about this — you'll have to find the bad driver and remove it or upgrade it to a version without the defect. One example of this are headphones that register themselves as input devices while not actually having any input capability.

Can I submit new/revised data files?

Absolutely! Almost all of the current data content of GCS was provided by helpful individuals other than me. If you have completely new content, please create a new library for it and send the resulting file. If, on the other hand, you're modifying one of the existing data files, please be sure to update to the latest version from the git repository first, make your changes, then submit a patch file of the differences. In either case, please either create a Pull Request or an Issue for the work and attach the new file or patch file to that.

How can I change where GCS loads settings from and to?

There are two ways to accomplish this. One is to make use of the command-line --settings option that explicitly tells GCS where to find its settings file. The other is to copy the settings file to be located next to the GCS executable. When a file named gcs_prefs.json is found next to the GCS executable, it will be used instead of the normal location. Note that this does not override the command-line option, so if you do both, the command-line option will take precedence.

When doing this, you may also want to change the location of the log file, which can be adjusted using the --log-file command-line option.

How can I convert old GCS files to the current format?

This depends greatly on just how old the file is. Files made prior to the v4.20 release need to be converted using the program found here: GCS JSON Updater. This will convert them to the v4.20 format.

Files created before v4.30 need to be converted using the v4.37.1 release. Either open and save each file with GCS v4.37.1 or you can use the command-line option to convert a bunch of files at once.

Once GCS v5.x.x can open the file, you can save it from GCS v5.x.x to have it stored in the current format.

How do I convert my all of my User Library data files to the current file format?

If you don't want to manually load and then save each data file to convert it to the current file format, you can use the command-line to update every data file at once. How this works depends on your computer's operating system.

Warning: Misusing the command-line can seriously damage your operating system. Unless you know what you're doing, proceed carefully and don't deviate from the instructions below.

  1. Backup your User Library.
  2. Open a terminal (macOS and Linux) or the command prompt (Windows). On Windows, you can do this by typing "Command Prompt" in the Windows search bar and clicking on the first result.
  3. Issue the convert command: "PATH_TO_GCS" --convert "PATH_TO_USER_LIBRARY" substituting the full paths to GCS and the User Library as appropriate. Note that you should make sure the paths have quotes around them as shown above, in case they contain spaces.
    On Windows, the path to GCS might look like this: C:\Program Files\GCS\gcs.exe
    On macOS, the path to GCS might look like this: /Applications/GCS.app/Contents/MacOS/gcs
    On Linux, the path to GCS might look like this: /usr/local/bin/gcs
    The path to the User Library can be found by opening GCS, right-clicking on the User Library folder, selecting Configure, then copying everything in the Path field in the settings tab that comes up.
  4. When the command is run, it will start listing the files it is converting. Once it finishes, you can close the terminal. If the command gives you an error instead of listing your files, go back to step 3 and try again, double checking that your file paths are correct and that you're typing everything correctly, spaces included. Note that files that are too old to be opened by the current version may need you to install an older version of GCS to do a conversion to bring them up to a version that the current version can process.
  5. Open GCS and verify that you can open your data files.

Can I define my own standard hit location tables and have them show up in the combo for selection?

Yes. Make sure to give the table a unique ID, then export it and place it in the "Body Types" directory inside the "Settings" directory in one of your GCS library directories (the User Library is a good choice for this, as it won't get overwritten when you update your libraries).

What operators and functions are available for use in attribute expressions?

You can find help for these in the Master Library/Markdown/Help folder.