osgx::platform

osgx/Linux.hpp provides X11/XRandr window helpers that are always compiled into libosgx (X11 is already a hard dependency of osgViewer's GLX backend on Linux, so this carries no more risk than the existing OpenGL dependency):

• alwaysOnTop(viewer, enabled=true) — pins the viewer's X11 window above other windows via the EWMH _NET_WM_STATE ClientMessage protocol.
• Monitor / listMonitors() — the real XRandR monitor layout (position/size in root-window coordinates; monitors are not assumed to be flush/adjacent).
• moveWindow(viewer, x, y, width=-1, height=-1) — repositions (and optionally resizes) an already-realized X11 window, keeping OSG's own viewport/camera bookkeeping in sync.

osgx/GraphicsWindowEGL.hpp and osgx/GraphicsWindowGBM.hpp (gated behind OSGX_EGL/OSGX_GBM, requiring EGL and GBM+libdrm respectively via pkg-config; set via the OSGX_WITH_EGL/ OSGX_WITH_GBM CMake options, which auto-detect and compile into libosgx when found — same pattern as OSGX_WITH_IMGUI) provide two experimental osgViewer::GraphicsWindow factories:

• createEGLWindow(traits) — an ordinary X11 window driven by EGL instead of GLX. Skeleton/proof-of-concept: no input/resize handling, but does watch WM_DELETE_WINDOW so closing the window shuts the viewer down cleanly.
• createGBMWindow(traits) — direct-scanout DRM/KMS + GBM, no X11 or window manager at all (kiosk/embedded-style). Requires exclusive DRM master access, so it fails under a running X server or Wayland compositor.

osgx/Cursor.hpp provides mouse capture built purely on portable osgGA/osgViewer virtuals (GraphicsWindow::useCursor(), View::requestWarpPointer()) — no X11 dependency of its own, but grouped under osgx::platform since that's where the motivating need already lived:

• setCursorVisible(view, visible=true) / warpPointer(view, x, y) — small standalone action helpers (not a get/set pair — OSG's GraphicsWindow has no visibility getter of its own).
• PointerCapture — a GUIEventHandler implementing the standard hide+warp+accumulate trick for turntable/FPS-style relative-motion look controls: while setCaptured(true), hides the cursor and re-centers it on every move, accumulating the delta for consume() to poll once per update traversal. Not true OS-level pointer confinement (nothing stops the cursor visibly darting to the screen edge for one frame between warps on some window managers) — that needs real XGrabPointer work, tracked in TODO.md.

Migrated from OpenSceneGraph.py's pyosg/linux/ (it was never actually OSG.py-specific); see examples/osgx-platform.cpp for a worked example of all of the above, including both alternate window backends.