Here is a list of all files with brief descriptions:

include
externs.h	Declarations for external game and runtime functions
functions.h	Declarations for reconstructed game functions
game.h	Shared Win32 declarations, types and library interfaces
game_data.h	Game data structures, constants and packed resource formats
globals.h	Shared globals and their retail address annotations
site
src
ix
dsp.cpp	DirectSound initialization, device configuration and buffers
dsps.cpp	DirectSound streaming ring buffers
dspv.cpp	DirectSound voices, sample playback and voice parameters
ix.h	Audio classes, DirectSound interfaces and shared ix state
ixfile.cpp	File I/O wrappers for the audio streamer
lzo1x.cpp	LZO1X decompression for packed audio streams
mixer.cpp	Software-mixer scheduling and buffer management
sample.cpp	Sample loading, format conversion and sample lifetime
sound.cpp	Sound objects, playback control and completion callbacks
streamer.cpp	Audio stream management, buffering and playback control
streamfile.cpp	Stream-file objects and read status
system.cpp	Sound-system startup, master volume and voice allocation
thread.cpp	Worker thread and asynchronous audio chunk delivery
auto.c	Autopilot travel and interstitial flight sequences
brains.c	Ship intelligence and missions
campaign.c	Campaign start, continue prompt and game loop
campglob.c	Campaign globals and campaign scripts
carrier.c	Carrier fighter launches
clock.c	Splits game clock ticks
cockpt.c	Cockpit displays, HUD messages and VDUs
comm.c	Communications menu and transmissions
config.c	Reads the WINGCMDR.CFG installation configuration
console.cpp	Owner and C wrappers of the Win32 developer overlay console
damage.c	Cockpit damage display
datafile.c	Data file I/O
death.c	Death sequence
debug.cpp	Win32 developer overlay console
destroy.c	Ship destruction and mission ejection pods
dib.cpp	DirectDraw DIB display, frame timing and palettes
disk.c	Packet loading, text contexts and input waits
eject.c	Player ejection and stranding sequences
eventmgr.c	Win32 library port: random, fixed-point math, text, strings and events
fade.c	Palette transition step
fields.c	Asteroid and mine hazard fields
fl.c	Flight maneuvers
fleetvw.c	Fleet overview view
fltsetup.c	Spaceflight setup: shapes, cockpit, constellations and music
fstrcat.c	String concatenation shim
gameflow.c	Cutscene engine and game flow
geom.c	Ship velocity limits, vector arithmetic and orientation geometry
getmode.c	Queries the graphics mode
globals.c	Reference-build placeholder; native-only storage is omitted
gr.c	Shape decoding, viewport drawing and raster effects
grdriver.c	Loads the graphics driver
hexnum.c	Hexadecimal number parser
hotspot.c	Scene hotspot selection
hugemove.c	Overlap-safe huge memory copy
iffindex.c	Scene chunk decoding
iffload.c	Cutscene IFF resource parsing and release
input.c	Menu input devices and joystick button events
intro.c	Title orchestra sequence and victory fireworks
joycal.c	Joystick calibration file and calibrated reads
joypres.c	Joystick presence query
joystick.c	Joystick sampling
jump.c	Objectives, warp arrival and star-system jumps
kbmouse.c	Keyboard mouse pump
loadmisn.c	Loads mission data
logic.c	Ship AI bookkeeping: alerts, collisions, goals and squads
main.c	Main application loop and spaceflight frame
memapi.c	Memory stack frames and packet handles
memfree.c	Available main memory
message.c	Flight input setup, fatal errors and on-screen messages
midscene.c	Mid-mission ejection scene
mission.c	Mission setup, action spheres and ship loading
mono.c	MONODEBG developer channel
mousepos.c	Sets the mouse position
music.c	Music and sound-effect control
nav.c	Navigation map
nearheap.c	Near heap allocator
optmenu.c	Text input and modal text panels
orders.c	Wingman orders and landing requests
packet.c	Packet sections and data file handles
palalloc.c	Space palette layout and contiguous palette-entry reservation
palette.c	Saves and restores the game palette
palfade.c	Fades a viewport palette towards a colour
pan.c	Pans between screens
parsenum.c	Number parser
personnel.c	Personnel database, campaign chalkboard and pilot transfer
pktsize.c	Packet size
pload.c	Packet loader (Library\Source\Pload.c)
replay.c	Canned-scene playback
resread.c	Reads packet section data
screen.c	Full-screen DIB viewport setup
select.c	Weapon selection
ship.c	Space objects: creation, weapons, movement and damage
shpext.c	Shape frame extent
smart.c	Pilot steering, formation flying and maneuver selection
sound.c	Wave playback, sound bookkeeping and volume settings
spc.c	Space views, star field and object simulation
speech.c	Speech packets and speech cache
starfld.c	Fireworks and constellation fields
startup.c	Game startup and main
stream.cpp	Game wrappers around the audio streamer
strwidth.c	Clamped text pixel width
suffix.c	Graphics file suffixes and character conversion
taperec.c	Canned-scene tape recorder
target.c	Target display
text.c	Cinematic sprite-font renderer
textfmt.c	Formatted text output
timer.c	Multimedia frame timer callback
titlemnu.c	Joystick calibration, title menu and barracks screen
turret.c	Fleet overview, target camera and turret guns
usedcols.c	Collects the palette indices in use
version.c	Game version string
viewrect.c	Sets a viewport rectangle
vpalloc.c	Viewport buffer allocation
vpfree.c	Frees a viewport
waitkey.c	Waits for a queued input press
winmain.c	Win32 entry point, window, joystick, guarded heap and keyboard state
wipe.c	Viewport wipe transitions