raven-branch was a branch in the Chocolate Doom Subversion repository that integrated the source code to the Raven games Heretic and Hexen into the Chocolate Doom code base. The branch was started following the resolution of the source code licensing issue with the Raven code.
To support the games, radical restructuring of the Chocolate Doom source code was necessary. The purpose of this was to separate the existing code into common and Doom-specific parts. The Heretic and Hexen code were then updated to interface with the common code.
The approach taken by Chocolate Doom differs from the common approach taken by other ports to support Heretic and Hexen. For example, ZDoom and Eternity have taken the approach of creating a combined engine that is generic enough to support all games. This approach reduces code duplication. However, Chocolate Doom's goals are to preserve the behavior of the original games as closely as possible. To achieve this, the source code to the three games is maintained separately, depending only on some common code that is shared between them. This approach results in duplicated code, with the advantage of avoiding large changes that might affect compatibility.
The portions of code that are common to the three games are currently:
- System-specific code (i_*):
- ENDOOM support
- Low-level SDL video code (i_video.c) and scaling (i_scale.c)
- Low-level sound effect and music code
- Timer code (i_timer.c)
- Endianness conversion (i_swap.h)
- New low-level code:
- CD sound (i_cdmus.c) - for Hexen
- Hexen startup video code (i_videohr.c)
- Basic event handling (d_event.c) and ticcmd definitions (d_ticcmd.h) - needed for networking.
- Entry point (i_main.c) and command line argument code (m_argv.c)
- Configuration file parsing
- Fixed point math functions (m_fixed.c)
- Network subsystem (net_*)
- Trigonometry lookup tables (tables.c)
- Video functions (drawing patches, etc) (v_video.c)
- WAD code (w_*)
- Zone memory subsystem (z_*)
raven-branch is now obsolete. Version 2.0 of Chocolate Doom integrated the changes made on raven-branch and now includes support for Heretic and Hexen.