Map Merger

The Map Merger is a collection of scripts that keep this repository's maps in a format which is easier to track in Git and less likely to cause merge conflicts. When merge conflicts do occur, it can sometimes resolve them.

For detailed troubleshooting instructions and other tips, visit the Map Merger wiki article.

Installation

To install the Git hooks, open the tools/hooks/ folder and double-click Install.bat. Linux users run tools/hooks/install.sh.

Manual Use

If using a Git GUI which is not compatible with the hooks:

• Before committing, double-click Run Before Committing.bat
• When a merge has map conflicts, double-click Resolve Map Conflicts.bat

The console will show whether the operation succeeded.

For more details, see the Map Merger wiki article.

What Map Merging Is

The "map merge" operation describes the process of rewriting a map file written by the DreamMaker map editor to A) use a format more amenable to Git's conflict resolution and B) differ in the least amount textually from the previous version of the map while maintaining all the actual changes. It requires an old version of the map to use as a reference and a new version of the map which contains the desired changes.

Map Merge 2 adds multi-Z support, automatic handling of key overflow, better merge conflict prevention, and a real merge conflict resolver.

Code Structure

Frontend scripts are meant to be run directly. They obey the environment variables TGM to set whether files are saved in TGM (1) or DMM (0) format, and MAPROOT to determine where maps are kept. By default, TGM is used and the map root is autodetected. Each script may either prompt for the desired map or be run with command-line parameters indicating which maps to act on. The scripts include:

• convert.py for converting maps to and from the TGM format. Used by tgm2dmm.bat and dmm2tgm.bat.
• mapmerge.py for running the map merge on map backups saved by Prepare Maps.bat. Used by mapmerge.bat

Implementation modules:

• dmm.py includes the map reader and writer.
• mapmerge.py includes the implementation of the map merge operation.
• frontend.py includes the common code for the frontend scripts.

precommit.py is run by the Git hooks if installed, and merges the new version of any map saved in the index (git added) with the old version stored in Git when run.