StratoHAL

StratoHAL (libstrato) is a highly portable hardware abstraction layer (HAL) for game applications.

StratoHAL provides:

• Built-in platform initialization, game loop, and event callback mechanisms.
• API for 2D graphics, audio, and input.
• GPU acceleration as well as software rendering.

With 25+ years of its history as in-house software, it has been published as free/libre software to serve as a core building block of the Suika3 game scripting runtime. Today, it continues to evolve as an independent library, bridging classic and modern platforms.

Platforms

StratoHAL supports most major platforms that SDL3 covers. In addition, it also supports software rendering for small embedded devices and older computers before the GPU era.

• Windows
• macOS
• Linux
• *BSD (FreeBSD, NetBSD, and OpenBSD)
• iOS
• Android
• HarmonyOS NEXT (OpenHarmony)
• WebAssembly
• ChromeOS
• Solaris 10 / 11
• Haiku OS
• Unity (as a native plugin)
• Xbox (via Unity Plugin, DevKit required)
• PlayStation 4 / PlayStation 5 (via Unity Plugin, DevKit required)
• Switch / Switch 2 (via Unity Plugin, DevKit required)

Backends

Platform	Graphics	Audio	Input
Windows	DirectX 12/11/9 and GDI (fallback)	DirectSound 5	DirectInput 8 (for PS5 controllers) and GameInput (for Xbox controllers)
Microsoft GDK (PC and Xbox)	DirectX 12	XAudio2	XInput
macOS	Metal	AudioUnit	GameController
Linux	(Wayland, X11, KMS, fbdev) x (OpenGL ES2, OpenGL 3, software rendering)	ALSA	Wayland, X11, and evdev
FreeBSD	(Wayland, X11) x (OpenGL ES2, OpenGL 3, software rendering)	/dev/dsp	Wayland or X11
NetBSD	X11 x (OpenGL 3, software rendering)	/dev/audio	X11
OpenBSD	X11 x (OpenGL 3, software rendering)	/dev/audio	X11
Solaris 10	X11 x software rendering	/dev/audio	X11
Solaris 11	X11 x software rendering	/dev/dsp (OSS)	X11
Haiku OS	Haiku native + software rendering	Haiku native	Haiku native
MS-DOS PC-98	GDC 640x400 16-colors	None	Keyboard
MS-DOS PC/AT	VGA 640x480 16-colors	None	Keyboard

About the Name

"Strato" comes from a Latin word "stratum", i.e., a layer, for hardware abstraction.

Usage

Graphic and audio APIs are self-described in include/strato/strato.h.

Examples are found in Playfield Engine.

#include <strato/strato.h>

static char window_title[] = "Hello";
static bool need_exit;

static bool on_start(void)
{
        return true;
}

static bool on_update(void)
{
        if (need_exit)
                return false;

	return true;
}

static void on_render(void)
{
}

static void on_mouse_press(int button, int x, int y)
{
        if (button == HAL_MOUSE_LEFT)
                need_exit = true;
}

bool hal_bootstrap(char **title, int *width, int *height, struct hal_callback *cb)
{

	*title = window_title;
	*width = 640;
	*height = 480;

	cb->on_start = on_start;
	cb->on_update = on_update;
	cb->on_render = on_render;
	cb->on_mouse_press = on_mouse_press;

	return true;
}

HAL_DEFINE_MAIN()