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Core Math & Runtime Utility Library

A leaf library of fixed-point geometry, angle, distance/bounds, string and misc runtime helpers at 0x411950–0x412DE2 — the game's own libc-like layer that the flight model, AI, HUD and campaign map all call. It holds no state of its own; every function is a pure helper over the engine's F24.8 fixed-point vocabulary or plain C strings.

Provenance: Ghidra static analysis of the game executable with FA.SMS symbols applied; recorded in the symbol database and applied to the Ghidra project. Progress: reconstruction matrix. Markers follow spec-authoring.md: confirmed · inferred · unknown.

The library

The functions fall into four groups, all named by FA.SMS:

  • Geometry & angles — Angles/AngleOffNose/AnglesOffNose measure bearings between objects; Octant/Clock bucket a bearing into an 8-way octant or a 12-o'clock clock code; RotatedOffset/RotatedOffsetF24/GetRotatedOffsetF24 rotate a body-frame offset into world space; Move3d advances a point along a heading; InterpAngle/LimitAngle interpolate and wrap angles; TurnTowardAngle steps a heading toward a target.

  • Distance & bounds — DistToObj/DistToLine (point-to-object / point-to-segment), SpeedToXYZ (decompose a speed vector), InBounds/InBounds3/BoundsAnd/PointInBox (AABB tests), NearestObj (nearest of a set), SortObjs (sort by a key), ObjRadius, FeetToNM (unit convert), Vertical. confirmed

  • String helpers — Strend (end pointer), Strncpy, NextString (walk a packed string table), StringIsNumber/StringToNumber (parse). confirmed

  • Misc runtime — Checksum (a running checksum), MatchF24 (fixed-point compare with tolerance), MaybeExitToDOS (fatal-exit path), and LibraryStartup/LibraryShutdown (the library's own init/teardown). inferred

Core math & runtime utility library: fixed-point geometry, distance/bounds, string and misc runtime helpers over the F24.8 vocabulary, called throughout the flight model, AI, HUD and campaign map.

Functions

Full record: db/symbols/core-math.csv.

VA Symbol Role
0x411950 TurnTowardAngle step a heading toward a target angle
0x411A40 Angles bearing between two objects
0x411AF0 AngleOffNose angle of a target off the nose
0x411BD0 Clock bearing → 12-o'clock clock code
0x411CB0 Octant bearing → 8-way octant
0x411D10 RotatedOffset rotate a body-frame offset to world
0x411DE0 FeetToNM feet → nautical miles
0x411E00 InBounds 2D AABB test
0x411F50 SpeedToXYZ decompose a speed vector
0x4120C0 Move3d advance a point along a heading
0x412170 PointInBox point-in-box test
0x412200 DistToLine point-to-segment distance
0x412340 SortObjs sort objects by a key
0x412480 InterpAngle interpolate between angles
0x412B50 StringToNumber parse a numeric string
0x412CB0 NearestObj nearest object of a set
0x412DA0 LimitAngle wrap an angle into range
0x4562F0 Rand pseudo-random helper (Rand8/Rand16/Rand32 widths, InitRand seeds)
0x4561A0 Percent percentage / ratio helper
0x44A0A0 MultDiv32 32-bit multiply-then-divide (overflow-safe scale)
0x412DF0 CompareMemory memcmp-like compare (follows the primary range)
0x4C64B8 Swapmem swap two memory blocks
0x4C6524 DoWordToString 16-bit value to decimal string
0x4C65EC LMultDiv256 (a*b)/256 long multiply-divide
0x4C65F8 LFMult F24.8 fixed-point multiply
0x4C6604 LFDiv F24.8 fixed-point divide
0x4C6614 Abs integer absolute value (155 call sites)
0x4C6620 F24ToPA F24.8 angle to packed-angle
0x4C6638 PAToF24 packed-angle to F24.8
0x4C6654 Rotate2 rotate a 2-vector by an angle
0x4C6744 CpymemX extended memory copy (renderer's main copy primitive)
0x4C6838 CpymemXRemap copy through a remap table
0x4C686C Sprintf the engine's own printf (296 call sites)
0x4C6A84 FormatField fixed-width field formatter
0x4C6ADC NumberToAscii number to ASCII with separators
0x4C6C30 GetWordPointDelta 16-bit point delta
0x4C6D60 CpuId CPUID vendor/family probe (misc runtime)
0x4CCB88 ArcTan fixed-point arctangent
0x4124E0 SampleInit time-series sample ring init (tick + value records)
0x412550 SampleShutdown free a sample ring
0x412570 SampleUpdate push a timestamped sample
0x4125C0 SampleGet interpolated read-back (angle / 2×s16 / 3×s32 modes)
0x4B3010 CPUSpeed tick-calibrated CPU speed probe (returns CpuId results)

Open Questions

1. In-region functions with other homes

The 0x411950–0x412DE2 range also holds a few helpers that belong to other subsystems and are not claimed here: PrintShapeName (0x4129A0), SetHShake/SetVShake (0x412A30/ 0x412A60, the renderer's screen-shake state read by GG_Flush), and ButtonSound (0x412A90). They sit inside this utility unit's address range but are homed by their function, not their location; the Sample* cluster just past it (0x4124E0– 0x4125C0) is likewise held back pending identification (audio sample vs. statistical).

Status: open — home the in-region non-math helpers to renderer/sound as those passes reach them.

  • physics.md — the flight model, the biggest caller: bearings, rotation and bounds.
  • ai-interpreter.md — angle/distance helpers in the CT decision code.
  • campaign.md — the map screen's MAPWorldToScreen builds on these.