cgame runs its own PmoveSingle for the free camera using real time,
independent of server time. Solves pause freezing — camera moves
smoothly while svs.time is frozen.
Changes:
- usercmd_t: add optional origin[3] with 1-bit flag (zero cost for
normal gameplay, 13 bytes during demo viewing)
- msg.c: serialize optional origin in usercmd delta encoding
- CG_SETCLIENTORIGIN trap: cgame sends camera origin to engine
- cl_input.c: CL_FinishMove writes cgame origin into usercmd
- cg_predict.c: CG_PredictPlayerState runs local PmoveSingle for
free camera in svDemo mode, sends origin via trap for PVS
- cg_snapshot.c: detect follow→free camera transition, init camera
from last known position
- cg_main.c: detect svDemo mode from CS_SVDEMO configstring,
lazy-init camera from first snapshot's spectator spawn
- g_main.c: G_InitGame sets CS_SVDEMO configstring, G_RunFrame
copies cmd.origin to ps.origin for PVS instead of ClientThink_real
- bg_public.h: CS_SVDEMO configstring index (26)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
