Implement use of E_NO_POWER_DECAY on top-tier engines/motors (catacly…

…smbnteam#2726)

* Implement use of E_NO_POWER_DECAY on top-tier engines/motors

* Description updates per feedback

* Update vehicle_drag_test.cpp

data/json/items/vehicle/engine.json

@@ -279,7 +279,7 @@
     "copy-from": "engine_gasoline",
     "type": "ENGINE",
     "name": { "str": "1350 hp gas turbine engine" },
-    "description": "A gas turbine engine, usually used for military vehicles.  Known for its high rate of fuel consumption.",
+    "description": "A gas turbine engine, usually used for military vehicles.  Known for its high rate of fuel consumption, but installing multiple turbines will not affect vehicle power.",
     "weight": "1130000 g",
     "volume": "45 L",
     "price": 96000,
@@ -291,7 +291,7 @@
     "copy-from": "engine_gasoline",
     "type": "ENGINE",
     "name": { "str": "1900 hp gas turbine engine" },
-    "description": "A large gas turbine engine, usually used for military helicopters.  Known for its high rate of fuel consumption.",
+    "description": "A large gas turbine engine, usually used for military helicopters.  Known for its high rate of fuel consumption, but installing multiple turbines will not affect vehicle power.",
     "weight": "1582000 g",
     "volume": "63 L",
     "price": 192000,
@@ -303,7 +303,7 @@
     "copy-from": "engine_gasoline",
     "type": "ENGINE",
     "name": { "str": "6000 hp gas turbine engine" },
-    "description": "A massive gas turbine engine, used to power the V-22 Osprey.  Known for its high rate of fuel consumption.",
+    "description": "A massive gas turbine engine, used to power the V-22 Osprey.  Known for its high rate of fuel consumption, but installing multiple turbines will not affect vehicle power.",
     "weight": "3164000 g",
     "volume": "95 L",
     "price": 960000,

data/json/items/vehicle/motors.json

@@ -18,7 +18,7 @@
     "type": "GENERIC",
     "id": "motor_enhanced",
     "name": { "str": "enhanced electric motor" },
-    "description": "A very powerful and yet lightweight electric motor.  Useful for crafting.",
+    "description": "A very powerful and yet lightweight electric motor.  Useful for crafting, and its advanced design means it won't suffer power loss if multiple are installed on a vehicle.",
     "weight": "100 kg",
     "material": [ "superalloy" ],
     "volume": "20 L",
@@ -30,7 +30,7 @@
     "type": "GENERIC",
     "id": "motor_super",
     "name": { "str": "super electric motor" },
-    "description": "The most powerfull electric motor on the market.  Useful for crafting.",
+    "description": "The most powerfull electric motor on the market.  Useful for crafting, and its advanced design means it won't suffer power loss if multiple are installed on a vehicle.",
     "weight": "125 kg",
     "volume": "25 L",
     "price": 80000,

data/json/vehicleparts/combustion.json

@@ -43,7 +43,8 @@
     "fuel_options": [ "gasoline", "diesel", "lamp_oil", "jp8", "motor_oil", "avgas", "biodiesel" ],
     "m2c": 60,
     "//": "25% energy efficiency",
-    "description": "An advanced combustion engine.  Burns gasoline or diesel or aviation fuel from a tank in the vehicle.  Can also burn lamp oil, though somewhat less efficiently.  Better power-to-weight ratio than a traditional engine, but consumes more fuel."
+    "extend": { "flags": [ "E_NO_POWER_DECAY" ] },
+    "description": "An advanced combustion engine.  Burns gasoline or diesel or aviation fuel from a tank in the vehicle.  Can also burn lamp oil, though somewhat less efficiently.  Better power-to-weight ratio than a traditional engine but consumes more fuel, its power will not diminish even when multiple of them are installed."
   },
   {
     "id": "diesel_engine_i6",

data/json/vehicleparts/motor.json

@@ -115,6 +115,7 @@
     "type": "vehicle_part",
     "name": { "str": "enhanced electric motor" },
     "item": "motor_enhanced",
+    "description": "A more advanced electric motor, its power will not diminish even when multiple of them are installed.",
     "durability": 200,
     "power": 282000,
     "energy_consumption": 300000,
@@ -132,6 +133,7 @@
       { "item": "bearing", "count": [ 20, 50 ] },
       { "item": "cable", "charges": [ 10, 15 ] }
     ],
+    "extend": { "flags": [ "E_NO_POWER_DECAY" ] },
     "damage_reduction": { "all": 50 }
   },
   {
@@ -140,6 +142,7 @@
     "type": "vehicle_part",
     "name": { "str": "super electric motor" },
     "item": "motor_super",
+    "description": "A more advanced electric motor, its power will not diminish even when multiple of them are installed.",
     "durability": 400,
     "power": 475000,
     "energy_consumption": 500000,
@@ -157,6 +160,7 @@
       { "item": "bearing", "count": [ 25, 60 ] },
       { "item": "cable", "charges": [ 20, 30 ] }
     ],
+    "extend": { "flags": [ "E_NO_POWER_DECAY" ] },
     "damage_reduction": { "all": 60 }
   }
 ]

tests/vehicle_drag_test.cpp

@@ -245,8 +245,8 @@ TEST_CASE( "vehicle_drag", "[vehicle] [engine]" )
     test_vehicle_drag( "car", 0.294604, 2.473484, 1167.310417, 11916, 14350 );
     test_vehicle_drag( "car_mini", 0.294604, 1.816015, 1285.546875, 12157, 14580 );
     test_vehicle_drag( "car_sports", 0.294604, 2.547639, 1442.767500, 20848, 24904 );
-    test_vehicle_drag( "car_sports_atomic", 0.294604, 3.788275, 1787.798958, 23696, 24593 );
-    test_vehicle_drag( "car_sports_electric", 0.294604, 3.397004, 1923.776250, 23815, 24712 );
+    test_vehicle_drag( "car_sports_atomic", 0.294604, 3.788275, 1787.798958, 25635, 26601 );
+    test_vehicle_drag( "car_sports_electric", 0.294604, 3.397004, 1923.776250, 25753, 26718 );
     test_vehicle_drag( "electric_car", 0.304762, 2.485556, 1173.007292, 16208, 16826 );
     test_vehicle_drag( "rara_x", 0.880425, 2.267517, 1180.809267, 8353, 8670 );
     test_vehicle_drag( "suv", 0.294604, 2.914201, 1178.826786, 13988, 16827 );