Add current, max and average velocity as stat (#912)

* Add current, max and average velocity as stat

src/g_levellocals.h

@@ -614,6 +614,9 @@ public:
 	int			total_monsters;
 	int			killed_monsters;
 
+	double      max_velocity;
+	double      avg_velocity;
+
 	double		gravity;
 	double		aircontrol;
 	double		airfriction;

src/gamedata/statistics.cpp

@@ -599,3 +599,13 @@ ADD_STAT(statistics)
 	StoreLevelStats(primaryLevel);	// Refresh the current level's results.
 	return GetStatString();
 }
+
+ADD_STAT(velocity)
+{
+	FString compose;
+	if (players[consoleplayer].mo != NULL && gamestate == GS_LEVEL) {
+		compose.AppendFormat("Current velocity: %.2f\n", players[consoleplayer].mo->Vel.Length());
+		compose.AppendFormat("Level %s - Velocity Max: %.2f, Velocity Average: %.2f\n", primaryLevel->MapName.GetChars(), primaryLevel->max_velocity, primaryLevel->avg_velocity);
+	}
+	return compose;
+}

src/p_setup.cpp

@@ -264,6 +264,8 @@ void FLevelLocals::ClearLevelData()
 	total_monsters = total_items = total_secrets =
 	killed_monsters = found_items = found_secrets = 0;
 
+	max_velocity = avg_velocity = 0;
+
 	for (int i = 0; i < 4; i++)
 	{
 		UDMFKeys[i].Clear();

src/p_tick.cpp

@@ -180,5 +180,9 @@ void P_Ticker (void)
 		Level->maptime++;
 		Level->totaltime++;
 	}
+	if (players[consoleplayer].mo != NULL) {
+		if (players[consoleplayer].mo->Vel.Length() > primaryLevel->max_velocity) { primaryLevel->max_velocity = players[consoleplayer].mo->Vel.Length(); }
+		primaryLevel->avg_velocity += (players[consoleplayer].mo->Vel.Length() - primaryLevel->avg_velocity) / primaryLevel->maptime;
+	}
 	StatusBar->CallTick();		// Status bar should tick AFTER the thinkers to properly reflect the level's state at this time.
 }