camera: add PipeWire camera support

The PipeWire camera will enumerate the pipewire Video/Source nodes with
their formats.

When capturing is started, a stream to the node will be created and
frames will be captured.

cmake/sdlchecks.cmake

@@ -139,13 +139,16 @@ macro(CheckPipewire)
     if(PC_PIPEWIRE_FOUND)
       set(HAVE_PIPEWIRE TRUE)
       sdl_glob_sources("${SDL3_SOURCE_DIR}/src/audio/pipewire/*.c")
+      sdl_glob_sources("${SDL3_SOURCE_DIR}/src/camera/pipewire/*.c")
       set(SDL_AUDIO_DRIVER_PIPEWIRE 1)
+      set(SDL_CAMERA_DRIVER_PIPEWIRE 1)
       if(SDL_PIPEWIRE_SHARED AND NOT HAVE_SDL_LOADSO)
         message(WARNING "You must have SDL_LoadObject() support for dynamic PipeWire loading")
       endif()
       FindLibraryAndSONAME("pipewire-0.3" LIBDIRS ${PC_PIPEWIRE_LIBRARY_DIRS})
       if(SDL_PIPEWIRE_SHARED AND PIPEWIRE_0.3_LIB AND HAVE_SDL_LOADSO)
         set(SDL_AUDIO_DRIVER_PIPEWIRE_DYNAMIC "\"${PIPEWIRE_0.3_LIB_SONAME}\"")
+        set(SDL_CAMERA_DRIVER_PIPEWIRE_DYNAMIC "\"${PIPEWIRE_0.3_LIB_SONAME}\"")
         set(HAVE_PIPEWIRE_SHARED TRUE)
         sdl_link_dependency(pipewire INCLUDES $<TARGET_PROPERTY:PkgConfig::PC_PIPEWIRE,INTERFACE_INCLUDE_DIRECTORIES>)
       else()