Make car handling cvars latched/serverinfo and document tuning in server config

Ensure all vehicle handling car_* cvars are synchronized to clients and applied
in a controlled way during live matches.

- Set car handling cvars in g_main.c to CVAR_SERVERINFO | CVAR_LATCH
  so values are available to cgame prediction while runtime changes are delayed
  until restart/round transition.
- Keep cgame read path aligned with serverinfo updates (initial parse in init,
  re-parse on CS_SERVERINFO changes).
- Expand server_example.cfg with a dedicated vehicle handling section and
  per-cvar descriptions for consistent admin-side tuning.

Author: Perle2212

baseq3r/server_example.cfg

@@ -101,6 +101,25 @@
 //	Weapon Respawn Time [in seconds] (Default: 5)
 	g_weaponrespawn 5
 
+//	Vehicle handling (physics/prediction)
+//	All values are server-authoritative and published via serverinfo.
+//	Changes are latched and become active on map restart / next round load.
+//	Recommended: keep these identical across a season/match format.
+	car_spring "120"
+	car_shock_up "12"
+	car_shock_down "11"
+	car_swaybar "20"
+	car_wheel "2400"
+	car_wheel_damp "140"
+	car_frontweight_dist "0.5"
+	car_IT_xScale "1.0"
+	car_IT_yScale "1.0"
+	car_IT_zScale "1.0"
+	car_body_elasticity "0.05"
+	car_air_cof "0.31"
+	car_air_frac_to_df "0.5"
+	car_friction_scale "1.1"
+
 //	allow Voting?
 //	Vote for:
 //	— map

engine/code/game/g_main.c

@@ -281,22 +281,24 @@ static cvarTable_t		gameCvarTable[] = {
 { &g_useFuel, "g_useFuel", "1", CVAR_ARCHIVE | CVAR_SERVERINFO, 0, qfalse },
 
         // car variables
-	{ &car_spring, "car_spring", "120", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_shock_up, "car_shock_up", "12", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_shock_down, "car_shock_down", "11", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_swaybar, "car_swaybar", "20", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_wheel, "car_wheel", "2400", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_wheel_damp, "car_wheel_damp", "140", CVAR_SERVERINFO, 0, qfalse },
-
-	{ &car_frontweight_dist, "car_frontweight_dist", "0.5", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_IT_xScale, "car_IT_xScale", "1.0", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_IT_yScale, "car_IT_yScale", "1.0", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_IT_zScale, "car_IT_zScale", "1.0", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_body_elasticity, "car_body_elasticity", "0.05", CVAR_SERVERINFO, 0, qfalse },
-
-	{ &car_air_cof, "car_air_cof", "0.31", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_air_frac_to_df, "car_air_frac_to_df", "0.5", CVAR_SERVERINFO, 0, qfalse },
-	{ &car_friction_scale, "car_friction_scale", "1.1", CVAR_SERVERINFO, 0, qfalse },
+	// vehicle handling values are latched so they stay deterministic during an active match;
+	// all values are also published via serverinfo for cgame prediction setup.
+	{ &car_spring, "car_spring", "120", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_shock_up, "car_shock_up", "12", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_shock_down, "car_shock_down", "11", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_swaybar, "car_swaybar", "20", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_wheel, "car_wheel", "2400", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_wheel_damp, "car_wheel_damp", "140", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+
+	{ &car_frontweight_dist, "car_frontweight_dist", "0.5", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_IT_xScale, "car_IT_xScale", "1.0", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_IT_yScale, "car_IT_yScale", "1.0", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_IT_zScale, "car_IT_zScale", "1.0", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_body_elasticity, "car_body_elasticity", "0.05", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+
+	{ &car_air_cof, "car_air_cof", "0.31", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_air_frac_to_df, "car_air_frac_to_df", "0.5", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
+	{ &car_friction_scale, "car_friction_scale", "1.1", CVAR_SERVERINFO | CVAR_ARCHIVE | CVAR_LATCH, 0, qfalse },
 
         { &g_damageScale, "g_damageScale", "0.3", CVAR_ARCHIVE, 0, qfalse },
         { &g_vehicleDamageScale, "g_vehicleDamageScale", "5.0", CVAR_ARCHIVE, 0, qfalse },