Issue MegaMek 3360: Fixed takeoff logic and preventing smoke-assisted landings

megamek/src/megamek/common/Hex.java

@@ -575,21 +575,34 @@ public boolean isIgnitable() {
                 || containsTerrain(Terrains.FIELDS) || containsTerrain(Terrains.INDUSTRIAL));
     }
 
+    /**
+     * Returns true if the hex is valid for takeoff - either clear, has pavement, or a road
+     * @return
+     */
     public boolean isClearForTakeoff() {
-        for (final Integer i : terrains.keySet()) {
-            if (containsTerrain(i) && (i != Terrains.PAVEMENT) && (i != Terrains.ROAD) && (i != Terrains.FLUFF)
-                    && (i != Terrains.ARMS) && (i != Terrains.LEGS) && (i != Terrains.SNOW) && (i != Terrains.MUD)
-                    && (i != Terrains.SMOKE) && (i != Terrains.METAL_CONTENT)) {
-                return false;
-            }
+        if (hasPavementOrRoad()) {
+            return true;
         }
-        return true;
+        return getBaseTerrainType() == 0;
     }
 
     public boolean isClearForLanding() {
         return !containsTerrain(Terrains.IMPASSABLE);
     }
 
+    /**
+     * Returns the "Base Terrain" for the hex, or 0 if it is clear
+     * @return
+     */
+    public int getBaseTerrainType() {
+        for (int terrain : terrains.keySet()) {
+            if (Terrains.isBaseTerrain(terrain)) {
+                return terrain;
+            }
+        }
+        return 0;
+    }
+
     public int getFireTurn() {
         return fireTurn;
     }

megamek/src/megamek/common/IAero.java

@@ -515,19 +515,18 @@ default PilotingRollData checkLanding(EntityMovementType moveType, int velocity,
         boolean clear = false;
         for (Coords pos : landingPositions) {
             Hex hex = ((Entity) this).getGame().getBoard().getHex(pos);
-            if ((hex == null) || hex.hasPavement()) {
+            if ((hex == null) || hex.hasPavementOrRoad()) {
                 continue;
             }
-            if (hex.isClearHex()) {
+            if (hex.getBaseTerrainType() == 0) {
                 clear = true;
-            } else {
-                for (int terrain : hex.getTerrainTypes()) {
-                    if ((terrain == Terrains.WATER) && hex.containsTerrain(Terrains.ICE)) {
-                        continue;
-                    }
-                    if (Terrains.landingModifier(terrain, hex.terrainLevel(terrain)) > 0) {
-                        terrains.add(List.of(terrain, hex.terrainLevel(terrain)));
-                    }
+            }
+            for (int terrain : hex.getTerrainTypes()) {
+                if ((terrain == Terrains.WATER) && hex.containsTerrain(Terrains.ICE)) {
+                    continue;
+                }
+                if (Terrains.landingModifier(terrain, hex.terrainLevel(terrain)) > 0) {
+                    terrains.add(List.of(terrain, hex.terrainLevel(terrain)));
                 }
             }
         }

megamek/src/megamek/common/Terrains.java

@@ -559,4 +559,17 @@ public static int landingModifier(int terrainType, int  terrainLevel) {
                 return 0;
         }
     }
+
+
+    /**
+     * Returns true if the terrain is a base terrain type, excluding "Clear"
+     * @param terrainType
+     * @return
+     */
+    public static boolean isBaseTerrain(int terrainType){
+        return terrainType == WOODS || terrainType == WATER || terrainType == ROUGH
+            || terrainType == RUBBLE || terrainType == JUNGLE || terrainType == SAND
+            || terrainType == TUNDRA || terrainType == MAGMA || terrainType == FIELDS
+            || terrainType == INDUSTRIAL || terrainType == SPACE || terrainType == BUILDING;
+    }
 }