fix scannable ship types

The `$Scannable` field in objecttypes.tbl controls whether a ship can be targeted by the "target unscanned ship" key.  In retail, these were cargo containers and freighters.  This is independent of which ship types can actually be *scanned*, which in retail were cargo containers and *transports*, and were not connected to any field in objecttypes.tbl.

So, this PR renames the `$Scannable` field to `$Targetable as unscanned:`, to be clearer about what it actually does; and adds the missing counterpart `$Scannable by default:` flag to specify which ship types can actually be scanned.  Additionally, it fixes the retail inconsistency, moving the targetability from Freighter to Transport to match the scannability.

Note that this is only relevant for legacy scanning behavior.  Mods which use `$Unify scanning behavior:` do not experience the inconsistency and do not need either of the ship type flags.

Author: Goober5000

code/def_files/data/tables/objecttypes.tbl

@@ -53,8 +53,9 @@ $AI:
 	+Ignored on cripple by:	( "navbuoy" "sentry gun" "escape pod" "cargo" "support" "fighter" "bomber" "transport" "freighter" "awacs" "gas miner" "cruiser" "corvette" "capital" "super cap" "drydock" "knossos device" )	
 $Skip Death Roll Percent Chance: 0.0											
 
-$Name:					Cargo											
-$Scannable:				YES												
+$Name:						Cargo										
+$Targetable as unscanned:	YES											
+$Scannable by default:		YES											
 $Max Debris Speed:		200												
 $FF Multiplier:			0.10											
 $EMP Multiplier:		10.0											
@@ -156,6 +157,8 @@ $Praise Destruction:	YES
 $On Hotkey List:		YES												
 $Target as Threat:		YES												
 $Show Attack Direction:	YES												
+$Targetable as unscanned:	YES											
+$Scannable by default:	YES												
 $Max Debris Speed:		150												
 $FF Multiplier:			1.0												
 $EMP Multiplier:		2.0												
@@ -186,7 +189,6 @@ $Praise Destruction:	YES
 $On Hotkey List:		YES												
 $Target as Threat:		YES												
 $Show Attack Direction:	YES												
-$Scannable:				YES												
 $Max Debris Speed:		150												
 $FF Multiplier:			1.0												
 $EMP Multiplier:		1.75											

code/hud/hudtarget.cpp

@@ -1608,7 +1608,7 @@ int hud_target_ship_can_be_scanned(ship *shipp)
 		return 1;
 	} else if (Use_new_scanning_behavior) {
 		return 0;
-	} else if ((sip->class_type < 0) || !(Ship_types[sip->class_type].flags[Ship::Type_Info_Flags::Scannable])) {
+	} else if ((sip->class_type < 0) || !(Ship_types[sip->class_type].flags[Ship::Type_Info_Flags::Targetable_as_unscanned])) {
 		return 0;
 	}
 

code/playerman/playercontrol.cpp

@@ -1690,7 +1690,7 @@ bool player_inspect_cargo(float frametime, char *outstr)
 		// scannable cargo behaves differently.  Scannable cargo is either "scanned" or "not scanned".  This flag
 		// can be set on any ship.  Any ship with this set won't have "normal" cargo behavior
 		if (!(cargo_sp->flags[Ship::Ship_Flags::Scannable])) {
-			if (!(cargo_sip->flags[Ship::Info_Flags::Cargo] || cargo_sip->flags[Ship::Info_Flags::Transport])) {
+			if ((cargo_sip->class_type < 0) || !(Ship_types[cargo_sip->class_type].flags[Ship::Type_Info_Flags::Scannable_by_default])) {
 				return false;
 			}
 		}
@@ -1710,8 +1710,6 @@ bool player_inspect_cargo(float frametime, char *outstr)
 			auto cargo_name = (cargo_sp->cargo1 & CARGO_INDEX_MASK) == 0
 				? XSTR("Nothing", 1674)
 				: Cargo_names[cargo_sp->cargo1 & CARGO_INDEX_MASK];
-			//Why was this assert here? I'm not sure it makes much sense because any ship can be scanned and have cargo revealed...
-            //Assert(cargo_sip->flags[Ship::Info_Flags::Cargo] || cargo_sip->flags[Ship::Info_Flags::Transport]);
 
 			if (cargo_sp->cargo_title[0] != '\0') {
 				if (cargo_sp->cargo_title[0] == '#') {

code/ship/ship.cpp

@@ -6145,8 +6145,12 @@ static void parse_ship_type(const char *filename, const bool replace)
 		stuff_boolean_flag(stp->flags, Ship::Type_Info_Flags::Show_attack_direction);
 	}
 
-	if(optional_string("$Scannable:")) {
-		stuff_boolean_flag(stp->flags, Ship::Type_Info_Flags::Scannable);
+	if(optional_string("$Scannable:") || optional_string("$Targetable as unscanned:")) {
+		stuff_boolean_flag(stp->flags, Ship::Type_Info_Flags::Targetable_as_unscanned);
+	}
+
+	if(optional_string("$Scannable by default:")) {
+		stuff_boolean_flag(stp->flags, Ship::Type_Info_Flags::Scannable_by_default);
 	}
 
 	if(optional_string("$Warp Pushes:")) {

code/ship/ship_flags.h

@@ -230,7 +230,8 @@ namespace Ship {
         Target_as_threat,
         Show_attack_direction,
         No_class_display,
-        Scannable,
+        Targetable_as_unscanned,
+        Scannable_by_default,
         Warp_pushes,
         Warp_pushable,
         Turret_tgt_ship_tgt,