NSF Compilation

NSF Compilation

In Dn-FamiTracker, NSFs are compiled by translating the module data into binary data, before concatenating it to a compiled NSF driver. Of course, this is as complicated as it sounds. It's mostly done inside Compiler.cpp.

Overview

Nearly every format export is the same with subtle differences:

• clear log messages with CCompiler::ClearLog()
• detect if any NSFe features are used in a non-NSFe compatible format
• CCompiler::CompileData()
  • if this fails, we clean up CCompiler::Cleanup() and return
  • otherwise data and driver fits within 32kB, or it's m_bBankSwitched
• if it's m_bBankSwitched:
  • we need to ResolveLabelsBankswitched(); this can fail so return if we do fail
  • then we need to UpdateFrameBanks()
  • and UpdateSongBanks()
  • finally, we EnableBankswitching() in the driver by patching some flags in the song header
• otherwise, for nonbankswitched songs:
  • we ResolveLabels()
  • and we ClearSongBanks()
• finally, we deal with the rest:
  • update DPCM sample pointers UpdateSamplePointers()
  • CalculateLoadAddresses() depending on what mode we're in
• load the driver identifier with LoadNSFDRV() and driver proper with LoadDriver()
• set the addresses of the song and the driver SetDriverSongAddress()
• then we write out the file, specific to the format

Data Chunks

Each angstrom of data is stored in what's known as a Chunk.

CCompiler::CompileData()