824b4a2506
Aiming looked and behaved differently depending on whether the keyboard/menu was open: xr_input_try_overlay() claimed a hand's ray for its overlay whenever the overlay was merely visible, regardless of whether the ray was actually pointed at it - so with the keyboard open, aiming at the main game screen still showed a beam terminating at the keyboard's fixed depth, while closing the keyboard swapped in the old flat cross-shaped reticle at whatever the ray was really pointing at. Only claim an overlay when the ray is actually relevant this frame - a real hit, or a touch/drag begun on a previous frame still pending release - so a visible-but-unaimed-at overlay now falls through to the next-priority target. Give the game quad its own hit-test (xr_input_try_game_quad()) and the same billboarded laser-beam treatment as the overlays instead of the old flat reticle, so aiming looks and behaves identically everywhere - overlay open or not. The old reticle GL program/shaders are now fully dead and removed. No click/touch dispatch is added to the game quad itself; that's future work.