sdl2

BCR packaging summary for SDL2.

Public targets:

• @sdl2
• @sdl2//:sdl2_headers

Packaging notes:

• @sdl2 exports the SDL library and re-exports public headers in both SDL2/... and flat SDL.h include layouts for consumer compatibility.
• @sdl2//:sdl2_headers exports the public SDL headers plus the Bazel-generated SDL_config.h in the canonical SDL2/... layout.
• Internal src/**/*.h headers are kept private to the @sdl2 implementation.
• The Bazel-managed SDL config header is generated from the upstream template with rules_cc_autoconf.

Enabled backends:

• Linux: ALSA audio, X11 and Wayland video, OpenGL ES 2 rendering via EGL, Linux joystick/haptics, pthread timer/loadso/filesystem/power.
• macOS: Cocoa video, CoreAudio audio, Metal/OpenGL rendering, IOKit joystick/haptics, pthread timer/loadso/filesystem/power.
• Windows: WinMM audio, Windows video, Windows joystick/sensor, Windows timer/loadso/filesystem/power.

Limitations:

• Linux build does not currently enable Wayland libdecor, PulseAudio, or PipeWire.
• Linux desktop OpenGL/GLX and Vulkan are not currently enabled in-package.
• macOS currently disables HIDAPI in-package.
• Windows HIDAPI is wired through Bazel textual_hdrs because SDL textually includes src/hidapi/windows/hid.c.

Presubmit:

• Builds and tests @sdl2//:sdl2_headers_consumer_compile_test for SDL2/... includes and @sdl2//:sdl2_consumer_link_test for flat SDL.h includes.
• Uses the standard module presubmit path across all supported platforms on Bazel 8, Bazel 9, and rolling.