* dos: Some initial work.
* dos: Turn off buffer on stdio SDL_IOStreams.
Seeking breaks otherwise. We might be able to just fflush() before or seeking
instead?
* dos: Audio implementation using the Sound Blaster 16.
* dos: remove audio Pump interface.
Turns out DosBox-X was having trouble with the Sound Blaster or something;
standard DosBox works correctly directly from the interrupt handler, and
without doubling the buffer size.
* dos: just dump and restore the stdio buffer when seeking.
This is MUCH faster than just leaving buffering disabled, and also works
around getting bogus reads after an fseek. SDL_LoadWAV on test/sample.wav
no longer takes several seconds to finish, and comes up with the correct
data.
I wonder if we're triggering this in LoadWAV because we're malloc'ing data
between seeks/reads, and it's causing the djgpp transfer buffer to change. Or
maybe the Fat DS trick is confusing it? I don't know, I haven't had time to
debug it, it might just be a legit libc bug in djgpp too, for all I know.
* dos: Protect audio device "thread" iterations when streams are locked.
This uses an old trick we used in SDL 1.2 for MacOS Classic, which did its
audio callback in a hardware interrupt. If the audio is locked when the
interrupt fires, make a note of it and return immediately. When the lock is
released, if the interrupt has been fired, run the audio device iteration
right then.
Since there isn't a big device lock in SDL3 (available to the app, at least),
this keeps a counter of when any SDL_AudioStream is locked, which is probably
good enough.
* dos: Implemented initial video subsystem.
This uses VESA interfaces to manage the display and works with the software
renderer.
Events aren't hooked up yet, so prepare to close DosBox on each run. :)
* dos: Whoops, forgot to add these to revision control. Core and Main support.
* dos: Wired up basic filesystem support.
This gets most of the rendering examples, which use SDL_GetBasePath() to
find textures to load, working.
* dos: Fixed compiler warning.
* dos: Initial mouse support!
* dos: Move interrupt hooking code into core/dos.
* dos: Initial keyboard support!
* dos: Use a simple ring buffer for keyboard events.
Of course Quake 1 solved this better, haha. It's smart: less memory, dirt
simple, and you don't even have to worry about synchronizing with the
interrupt handler, because it's safe for both sides no matter when an
interrupt fires.
* ci: add djgpp job
[sdl-ci-filter djgpp]
[sdl-ci-artifacts]
* dos: Fix build issues after rebase onto current main
- SDL_runapp.c: Add SDL_PLATFORM_DOS to the exclusion list so the
generic
SDL_RunApp() is disabled when the DOS-specific one is compiled.
- SDL.c: Exclude SDL_Gtk_Quit() on DOS. DJGPP defines __unix__ which
sets
SDL_PLATFORM_UNIX, but DOS has no GTK/display server. The GTK source
is not compiled (CMake UNIX is false for DOS) so this was a link
error.
- sdlplatform.cmake: Add DOS case to SDL_DetectCMakePlatform so the
platform is properly detected from CMAKE_SYSTEM_NAME=DOS.
- i586-pc-msdosdjgpp.cmake: Add i386-pc-msdosdjgpp-gcc as a fallback
compiler name, since some DJGPP toolchain builds use the i386 prefix.
* Add 8-bit palette support to DOS VESA driver
* Add VBE page-flipping, state restore, and robust keyboard handling
- Implement double-buffered page-flipping for VBE modes with >1 image
page
- Save and restore full VBE state on video init/quit for clean mode
switching
- Improve DOS keyboard handling: support extended scancodes and Pause
key
- Lock ISR code/data to prevent page faults during interrupts
- Always vsync when blitting in single-buffered modes to reduce tearing
* Refactor Sound Blaster audio mixing to main loop
Move audio mixing out of IRQ handler to main loop for improved
stability and to avoid reentrancy issues. Add SDL_DOS_PumpAudio
function, update DMA buffer handling, and adjust sample rate to 22050
Hz.
Silence stale DMA buffer halves to prevent stutter during load.
* Add DOS timer support and update build config
* Add support for pre-SB16 8-bit mono Sound Blaster audio
Detect SB version and select 8-bit mono or 16-bit stereo mode.
Handle DMA and DSP setup for both SB16 and pre-SB16 hardware.
Add FORCE_SB_8BIT option for testing in DOSBox.
* Add SB Pro stereo support and simplify IRQ handler
* Add DOS joystick driver support
* Improve DOS hardware handling and clarify memory allocation
- Poll Sound Blaster DSP status instead of fixed delay after speaker-on
- Clarify DPMI conventional memory is always locked; update comments
- Document and justify DMA memory allocation strategy
- Free IRET wrapper after restoring interrupt vector to avoid leaks
- Throttle joystick axis polling to ~60 Hz to reduce BIOS timing loop
cost
- Always poll joystick buttons directly for responsiveness
* Query and use mouse sensitivity from INT 33h function 0x1B
* Add support for VESA banked framebuffer modes
Implement banked framebuffer access for VBE 1.2+ modes without LFB.
Detect and initialize banked modes, copy framebuffer data using bank
switching, and blank the framebuffer on mode set. Page-flipping is
disabled in banked mode.
* Add optional vsync to page flipping in DOS VESA driver
* Add cooperative threading support for DOS platform
* Move SoundBlaster audio mixing to SDL audio thread
* Fix DOS platform comments and workarounds for DJGPP support
* Fix SoundBlaster IRQ handling and DMA setup for DOS
- Pass IRQ number to DOS_EndOfInterrupt and handle slave PIC EOI
- Validate DMA channel from BLASTER variable
- Correct DMA page register selection for SB16
- Improve BLASTER variable parsing and error messages
- Unmask/mask IRQs on correct PIC in DOS_HookInterrupt
- Rename SDL_dosjoystick.c to SDL_sysjoystick.c
- Include SDL_main_callbacks.h in SDL_sysmain_runapp.c
- Add include guard to SDL_systhread_c.h
* Add DOS platform options and preseed cache for DJGPP
Disable unsupported SDL features when building for DOS. Add
PreseedDOSCache.cmake to pre-populate CMake cache variables for DJGPP.
* cmake: use a 8.3 naming scheme for tests on DOS
* Apply code style
* Update include/SDL3/SDL_platform_defines.h
Co-authored-by: Anonymous Maarten <madebr@users.noreply.github.com>
* Code review clean up
- Split DOS VESA mode-setting into its own file
- Replace magic numbers with named constants
- Update copyright dates to 2026
- Substract time taken by other threads form delays
* Fix DOS bugs and improve compatibility
- Disable fseeko64 for DJGPP due to broken implementation
- Refactor DOS timer delay to always yield and avoid busy-waiting
- Fix animated cursor rendering in DOS VESA backend
- Always set display mode when creating DOS VESA window
- Work around DJGPP allowing invalid file access in testfile.c
- Bump max threads to 16
- Apply workarounds for threading tests
* Add DOS platform documentation and fix a few issues
- Fix fullscreen default resolution
- Improve best mode matching
- Fix builds on GCC older than 7.0
- Fix text input events
* Fix keyboard mapping of "*"
* Fix running, and existing, under PCem
* Apply suggestions from code review
Co-authored-by: Cameron Cawley <ccawley2011@gmail.com>
* Pre-mix audio in ring buffer and copy to DMA via IRQ thread
* Video fixes and optimizations
* DOS: Fix Intel 740 and VGA compatability
* DOS: Update readme
* DOS: Fix thread ID, get GPU name
* DOS: Cap mouse range
* DOS: Map test resources to 8.3 names
* DOS: Skip unsupported WM color modes
* Fix "windowed" resolution selection
* DOS: Hide INDEX8 modes behind SDL_DOS_ALLOW_INDEX8_MODES
* Remove SDL_HINT_DOS_ALLOW_INDEX8_MODES and order modes logically
* Don't convert cursor if dest is not INDEX8
---------
Co-authored-by: Ryan C. Gordon <icculus@icculus.org>
Co-authored-by: Anonymous Maarten <anonymous.maarten@gmail.com>
Co-authored-by: Cameron Cawley <ccawley2011@gmail.com>
Co-authored-by: Gleb Mazovetskiy <glex.spb@gmail.com>
Co-authored-by: Jay Petacat <jay@jayschwa.net>
Tested-by: Cameron Cawley <ccawley2011@gmail.com>
- Initialize some out variables that are annotated inout in the function setting them.
- Fix 'dwVerHandle' might not be '0' warning from msvc analyzer calling GetFileVersionInfoA. MSDN says that
the lpdwHandle param to GetFileVersionInfoSize is optional (set to zero) and the dwHandle param to
GetFileVersionInfoA is ignored. msvc goes a step further and explicitly warns if dwHandle is not provably 0.
Fixes the following:
SDL3\src\stdlib\SDL_string.c(2359): warning C6054: String 'text' might not be zero-terminated.
SDL3\src\video\windows\SDL_windowsevents.c(897): warning C6001: Using uninitialized memory 'devName'.
SDL3\src\video\windows\SDL_windowskeyboard.c(644): warning C6388: 'dwVerHandle' might not be '0': this does not adhere to the specification for the function 'GetFileVersionInfoA'.
Visual Studio _still_ doesn't report itself as C99 compatible, afaict, but
does support the syntax as of VS2017 15.6, apparently.
This page mentions the first version of Visual Studio that handles hexidecimal
float notation:
https://stackoverflow.com/questions/18180116/vc-rejecting-hexadecimal-floating-point-constant?utm_source=chatgpt.com
If not Visual Studio, we also take the messier path for things that don't
report themselves as C99. Most things will take the cleaner path, though.
Closes#15276.
We might be setting an environment variable along with other application code setting environment variables (like code in SteamAPI_InitEx()) before initializing SDL.
cl.exe versions ≥v19.41 call this builtin for double → uint64_t
conversions on x86. SDL currently needs such conversions in:
* MainCallbackRateHintChanged()
* SDL_PrintFloat()
* WIN_ApplyWindowProgress()
This seems enough to justify implementing this function rather than
trying to work around it, as it was done in sdl12-compat:
https://github.com/libsdl-org/sdl12-compat/issues/352
This implementation was taken from ReactOS:
https://git.reactos.org/?p=reactos.git;a=commitdiff;h=f637e6b809adb5e0ae420ef4f80c73b19172a2e7
Passes the stdlib testautomation, and also matches the behavior of
Microsoft's 64-bit libc for the currently implementation-defined case
of calling SDL_PrintFloat() with values >SDL_MAX_UINT64.
The current implementation uses the returned address of the `dlsym` function
directly to load the `environ` symbol. But this function doesn't return the
address to the symbol itself, instead it returns the address to the location
where the actual address is stored, i.e. it's an additional indirection.
Consequently, the implementation fails to load and process the environment
variables successfully.
One example where this error shows up is in the `Dialog API`: in an `X11`
environment, the `zenity` driver requires access to the user's `DISPLAY` and
`XAUTHORITY` environment variables. Because these variables aren't transfered
to the `zenity` process, no dialogs are shown. This can be exercised in the
`test/testdialog.c` testprogram.
The fix changes the indirection level of the `dlsym` call from `char **` to
`char ***`, does a `NULL`-check in case the call failed, and returns the
dereferenced actual adress to the `environ` symbol.
This was intended to make the API public, so SDL_hashtable.h got an extreme
documentation makeover, but for now this remains a private header.
This makes several significant interface changes to SDL_HashTable, and
improves code that makes use of it in various ways.
- The ability to make "stackable" tables is removed. Apparently this still
worked with the current implementation, but I could see a future
implementation struggle mightily to support this. It'll be better for
something external to build on top of the table if it needs it, inserting a
linked list of stacked items as the hash values and managing them separately.
There was only one place in SDL using this, unnecessarily, and that has also
been cleaned up to not need it.
- You no longer specify "buckets" when creating a table, but rather an
estimated number of items the table is meant to hold. The bucket count was
crucial to our classic hashtable implementation, but meant less once we
moved to an Open Addressing implementation anyhow, since the bucket count
isn't static (and they aren't really "buckets" anymore either). Now you
can just report how many items you think the hash will hold and SDL will
allocate a reasonable default for you...or 0 to not guess, and SDL will
start small and grow as necessary, which is often the correct thing to do.
- There's no more SDL_IterateHashTableKey because there's no more "stackable"
hash tables.
- SDL_IterateHashTable() now uses a callback, which matches other parts of SDL,
and also lets us hold the read-lock for the entire iteration and get rid of
the goofy iterator state variable.
- SDL_InsertIntoHashTable() now lets you specify whether to replace existing
keys or fail if the key already exists.
- Callbacks now use SDL conventions (userdata as the first param).
- Other naming convention fixes.
I discovered we use a lot of hash tables in SDL3 internally. :) So the bulk
of this work is fixing up that code to use the new interfaces, and simplifying
things (like checking for an item to remove it if it already exists before
inserting a replacement...just do the insert atomically, it'll do all that
for you!).
The FORCEINLINE macro is also used by Windows SDK headers.
When it is an empty macro, FORCEINLINE-d functions will
get global visibility error and cause duplicate symbol link errors.
HRESULT_FROM_WIN32 is such a function.
Read-write locks are not recursive and can't be upgraded from one type to another, so it's not safe to lock the hash table and then call functions that operate on it. If you really want this functionality, we'd need to create unlocked versions of the hashtable functions and you would call those once you've taken a lock on the hashtable, and we'd have to assert that the operations you're doing are compatible with the type of lock you've taken.
All of that complicates working with hashtables, so if you need that type of access, you should probably just use external locking.
This can be reverted if a toolchain arrives that can handle C99 features like
variables declared in the middle of a scope, but for now we literally can't
compile SDL3 for this platform.
Fixes#11243.
We require stdbool.h in the build environment, so we might as well use the plain bool type.
If your environment doesn't have stdbool.h, this simple replacement will suffice:
typedef signed char bool;
