API Reference

API Reference Index

Free API exposes a subset of the Win32 API (~1998 era) backed by SDL3. The reference is split by header file. Each page covers types, constants, function signatures, behaviour notes, and working code examples.

Status legend IMPLEMENTED — full working impl PARTIAL — limited subset STUB — compiles, no-op HEADER_ONLY — macro / inline / typedef

🔢

Types & Handles

Scalar types (BOOL, DWORD, WORD…), opaque handle types (HWND, HDC, HBITMAP…), calling-convention macros, pointer-width integers.

Headers: minwindef.h · windef.h · winnt.h

🪟

Window & Input

Window creation and lifecycle, the WinAPI message loop, keyboard (VK_* codes), mouse (MK_* flags), cursor control, user timers, geometry helpers.

Headers: winuser.h · windows.h

🖼️

GDI — Bitmaps & DCs

Loading BMP files, memory DCs, bitmap blitting with StretchBlt, pixel-level read/write, colour macros, GDI object lifecycle.

Header: wingdi.h

🛠️

System & File Utilities

Timing (GetTickCount, Sleep), debug output, error codes, directory / file operations, memory macros, WinMain bridge, fopen path normaliser.

Headers: winbase.h · synchapi.h · sysinfoapi.h · debugapi.h

📁

Legacy File I/O & Directory

MSVC-style file search (_findfirst/_findnext/_findclose), low-level file access (_lopen/_lread/_lclose), directory helpers (_chdir/_getcwd/_mkdir), access() modes.

Headers: io.h · direct.h

🎵

Multimedia — MIDI, MCI & Timers

MIDI file playback via TinySoundFont + TinyMidiLoader over SDL3 audio, MCI command API, multimedia periodic timers, MIDI output volume control, SoundFont setup.

Headers: mmsystem.h · digitalv.h

Include order

Header include hierarchy

Understanding which header pulls in what helps avoid double-include issues.

<windows.h>          ← include this for almost everything
  ├── <winuser.h>      ← window, messages, input
  │     ├── <minwindef.h>
  │     └── <windef.h>
  ├── <minwindef.h>    ← scalar types
  ├── <windef.h>       ← handles, calling conventions
  ├── <winnt.h>        ← string types, HRESULT
  ├── <synchapi.h>     ← Sleep
  ├── <sysinfoapi.h>   ← GetTickCount
  ├── <handleapi.h>    ← CloseHandle (stub)
  ├── <debugapi.h>     ← OutputDebugString
  ├── <winbase.h>      ← file/dir/memory utilities
  ├── <rpcndr.h>       ← byte/small type aliases
  ├── <wingdi.h>       ← GDI bitmaps, DCs
  └── <winerror.h>     ← E_* / S_* error codes

<mmsystem.h>         ← MIDI, MCI, timers (included by windows.h)
  └── <mmiscapi2.h>

<io.h>               ← legacy file search (include separately)
<direct.h>           ← _chdir/_getcwd/_mkdir (include separately)