Feature - Black Ice terrain modification

megamek/i18n/megamek/common/messages.properties

@@ -424,6 +424,7 @@ Terrains.editorName.swamp=Swamp
 Terrains.editorName.mud=Mud
 Terrains.editorName.rapids=Rapids
 Terrains.editorName.ice=Ice
+Terrains.editorName.black_ice=Black Ice
 Terrains.editorName.snow=Snow
 Terrains.editorName.fire=Fire
 Terrains.editorName.smoke=Smoke
@@ -474,6 +475,7 @@ Terrains.editorTooltip.swamp=Swamp
 Terrains.editorTooltip.mud=Mud
 Terrains.editorTooltip.rapids=Rapids
 Terrains.editorTooltip.ice=Ice
+Terrains.editorTooltip.black_ice=Black Ice
 Terrains.editorTooltip.snow=Snow
 Terrains.editorTooltip.fire=Fire
 Terrains.editorTooltip.smoke=Smoke

megamek/i18n/megamek/common/options/messages.properties

@@ -129,6 +129,8 @@ GameOptionsInfo.option.minefields.displayableName=TacOps Minefields / BMM Minefi
 GameOptionsInfo.option.minefields.description=If checked, minefields can be used.\nChecked by default.
 GameOptionsInfo.option.hidden_units.displayableName=Hidden Units
 GameOptionsInfo.option.hidden_units.description=If checked, players may deploy units hidden.
+GameOptionsInfo.option.black_ice.displayableName=Black Ice
+GameOptionsInfo.option.black_ice.description=If checked, Black Ice may form on pavement if temperatures are below -30C. TO:AR p38\nDoes not affect Black Ice forming due to Ice Storms. TO:AR p58
 GameOptionsInfo.option.double_blind.displayableName=TacOps Double blind
 GameOptionsInfo.option.single_blind_bots.displayableName=(Unofficial) Default bots to single blind, when using TacOps Double blind
 GameOptionsInfo.option.double_blind.description=If checked, enemy units will only be visible if they are in line of sight of one or more of your units, or within sensor range. \nUnchecked by default.

megamek/src/megamek/common/Compute.java

@@ -576,6 +576,14 @@ public static boolean isPilotingSkillNeeded(Game game, int entityId,
             return true;
         }
 
+        // Check for black ice on pavement
+        if (destHex.containsTerrain(Terrains.BLACK_ICE)
+                && !(entity.getElevation() > destHex.getLevel())
+                && isPavementStep
+                && (movementType != EntityMovementType.MOVE_JUMP)) {
+            return true;
+        }
+
         // Check for water unless we're a hovercraft or naval or using a bridge
         // or flying or QuadVee in vehicle mode.
         if ((movementType != EntityMovementType.MOVE_JUMP)

megamek/src/megamek/common/Entity.java

@@ -7258,6 +7258,15 @@
         // move path has ice
         boolean isFoggy = game.getPlanetaryConditions().getFog() != PlanetaryConditions.FOG_NONE;
         boolean isDark = game.getPlanetaryConditions().getLight() > PlanetaryConditions.L_DUSK;
+        boolean isBlackIce;
+
+        if ((game.getPlanetaryConditions().getWeather() == PlanetaryConditions.WE_ICE_STORM)
+                || (game.getOptions().booleanOption(OptionsConstants.ADVANCED_BLACK_ICE)
+                && game.getPlanetaryConditions().getTemperature() <= PlanetaryConditions.BLACK_ICE_TEMP)) {
+            isBlackIce = true;
+        } else {
+            isBlackIce = false;
+        }
 
         // if we are jumping, then no worries
         if (moveType == EntityMovementType.MOVE_JUMP) {
@@ -7282,6 +7291,10 @@
             // ice conditions
         } else if (curHex.containsTerrain(Terrains.ICE)) {
             roll.append(new PilotingRollData(getId(), 0, "moving recklessly"));
+        } else if (curHex.containsTerrain(Terrains.BLACK_ICE)) {
+            roll.append(new PilotingRollData(getId(), 0, "moving recklessly"));
+        } else if (curHex.hasPavement() && isBlackIce) {
+            roll.append(new PilotingRollData(getId(), 0, "moving recklessly"));
         } else {
             roll.addModifier(TargetRoll.CHECK_FALSE, "not moving recklessly");
         }
@@ -7381,6 +7394,26 @@
         return roll;
     }
 
+    /**
+     * Checks if the entity is landing (from a jump) on black ice.
+     */
+    public PilotingRollData checkLandingOnBlackIce(
+            EntityMovementType overallMoveType, Hex curHex) {
+        PilotingRollData roll = getBasePilotingRoll(overallMoveType);
+
+        if (curHex.containsTerrain(Terrains.BLACK_ICE)) {
+            roll.append(new PilotingRollData(getId(), 0,
+                    "landing on black ice"));
+            addPilotingModifierForTerrain(roll);
+            adjustDifficultTerrainPSRModifier(roll);
+        } else {
+            roll.addModifier(TargetRoll.CHECK_FALSE,
+                    "hex is not covered by black ice");
+        }
+
+        return roll;
+    }
+
     /**
      * return a <code>PilotingRollData</code> checking for whether this Entity
      * moved too fast due to low gravity
@@ -7435,6 +7468,7 @@
 
         PilotingRollData roll = getBasePilotingRoll(overallMoveType);
         // If we aren't traveling along a road, apply terrain modifiers
+        // Unless said pavement has black ice
         if (!((prevStep == null || prevStep.isPavementStep()) && currStep.isPavementStep())) {
             addPilotingModifierForTerrain(roll, lastPos);
         }
@@ -7472,7 +7506,7 @@
         if (prevStep != null) {
             prevStepPavement = prevStep.isPavementStep();
         } else {
             prevStepPavement = prevHex.hasPavement();
         }
 
         // TODO: add check for elevation of pavement, road,
@@ -7487,9 +7521,17 @@
                                         || (game.getPlanetaryConditions()
                                                 .getWindStrength() >= PlanetaryConditions.WI_STORM))))
                 && (prevFacing != curFacing) && !lastPos.equals(curPos)) {
-            roll.append(new PilotingRollData(getId(),
-                    getMovementBeforeSkidPSRModifier(distance),
-                    "turning on ice"));
+            roll.append(new PilotingRollData(getId(), getMovementBeforeSkidPSRModifier(distance), "turning on ice"));
+            adjustDifficultTerrainPSRModifier(roll);
+            return roll;
+        } else if ((prevHex != null) && prevHex.containsTerrain(Terrains.BLACK_ICE)
+                && (((movementMode != EntityMovementMode.HOVER) && (movementMode != EntityMovementMode.WIGE))
+                || (((movementMode == EntityMovementMode.HOVER) || (movementMode == EntityMovementMode.WIGE))
+                    && ((game.getPlanetaryConditions().getWeather() == PlanetaryConditions.WE_HEAVY_SNOW)
+                    || (game.getPlanetaryConditions().getWindStrength() >= PlanetaryConditions.WI_STORM))))
+                && (prevFacing != curFacing) && !lastPos.equals(curPos)) {
+            addPilotingModifierForTerrain(roll, lastPos);
+            roll.append(new PilotingRollData(getId(), getMovementBeforeSkidPSRModifier(distance), "turning on black ice"));
             adjustDifficultTerrainPSRModifier(roll);
             return roll;
         } else if ((prevStepPavement

megamek/src/megamek/common/MoveStep.java

@@ -3018,6 +3018,28 @@ && getEntity().getPosition().equals(prev)
             return;
         }
 
+        // Be careful on pavement during cold weather, there may be black ice.
+        boolean useBlackIce = game.getOptions().booleanOption(OptionsConstants.ADVANCED_BLACK_ICE);
+        boolean goodTemp = game.getPlanetaryConditions().getTemperature() <= PlanetaryConditions.BLACK_ICE_TEMP;
+        boolean goodWeather = game.getPlanetaryConditions().getWeather() == PlanetaryConditions.WE_ICE_STORM;
+
+        if (isPavementStep && ((useBlackIce && goodTemp) || goodWeather)) {
+            if (destHex.containsTerrain(Terrains.BLACK_ICE)){
+                mp ++;
+            }
+            if (destHex.containsTerrain(Terrains.BLACK_ICE)
+                    && !isCareful()
+                    && (nDestEl == destHex.getLevel())) {
+                mp--;
+            }
+            if (isPavementStep
+                    && !destHex.containsTerrain(Terrains.BLACK_ICE)
+                    && isCareful()) {
+                mp++;
+            }
+
+        }
+
         // Account for terrain, unless we're moving along a road.
         if (!isPavementStep()) {
 

megamek/src/megamek/common/PlanetaryConditions.java

@@ -67,6 +67,7 @@ public class PlanetaryConditions implements Serializable {
     public static final int WE_HEAVY_HAIL       = 13;// NYI
     public static final int WE_LIGHTNING_STORM  = 14;// NYI
     //  public static final int WE_BLIZZARD         = 11; does not exist anymore
+    public static final int BLACK_ICE_TEMP      = -30;
     private static final String MSG_NAME_WEATHER_CLEAR = Messages.getString("PlanetaryConditions.DisplayableName.Weather.Clear");
     private static final String MSG_NAME_WEATHER_LIGHTRAIN = Messages.getString("PlanetaryConditions.DisplayableName.Weather.Light Rain");
     private static final String MSG_NAME_WEATHER_MODRAIN = Messages.getString("PlanetaryConditions.DisplayableName.Weather.Moderate Rain");
@@ -373,8 +374,8 @@ public int getLightHitPenalty(boolean isWeapon) {
 
         return penalty;
     }
-    
-    /** 
+
+    /**
      * Returns true when the light conditions give a hit penalty and
      * the hit penalty can be offset by a searchlight, i.e. in full moon,
      * moonless and pitch black night.
@@ -397,11 +398,11 @@ public boolean isIlluminationEffective() {
     public static boolean requiresLowTemp(int weather) {
         return weather == WE_LIGHT_HAIL ||
                 weather == WE_HEAVY_HAIL ||
-                weather == WE_LIGHT_SNOW || 
+                weather == WE_LIGHT_SNOW ||
                 weather == WE_SLEET ||
                 weather == WE_SNOW_FLURRIES ||
                 weather == WE_HEAVY_SNOW ||
-                weather == WE_ICE_STORM || 
+                weather == WE_ICE_STORM ||
                 weather == WE_MOD_SNOW;
     }
 
@@ -775,7 +776,7 @@ public int getVisualRange(Entity en, boolean targetIlluminated) {
             isAero = (en.isAero()) && !isLargeCraft;
         }
         // anything else is infantry
-        
+
         // Beyond altitude 9, Aeros can't see. No need to repeat this test.
         if (isAero && (en.getAltitude() > 9)) {
             return 0;

megamek/src/megamek/common/Terrain.java

@@ -358,6 +358,11 @@ public void pilotingModifier(EntityMovementMode moveMode, PilotingRollData roll,
                     roll.addModifier(4, "Ice");
                 }
                 break;
+            case Terrains.BLACK_ICE:
+                if ((moveMode != EntityMovementMode.HOVER) && (moveMode != EntityMovementMode.WIGE)) {
+                    roll.addModifier(4, "Black Ice");
+                }
+                break;
             case Terrains.INDUSTRIAL:
                 roll.addModifier(1, "Industrial Zone");
                 break;
@@ -498,6 +503,7 @@ public int movementCost(Entity e) {
                 }
                 return Math.max(0, mp);
             case Terrains.ICE:
+            case Terrains.BLACK_ICE:
                 if ((moveMode == EntityMovementMode.HOVER) || (moveMode == EntityMovementMode.WIGE)) {
                     return 0;
                 }
@@ -664,6 +670,8 @@ public boolean isValid(StringBuffer errBuff) {
             rv = false;
         } else if (type == Terrains.ICE && level != 1) {
             rv = false;
+        } else if (type == Terrains.BLACK_ICE && level != 1) {
+            rv = false;
         } else if (type == Terrains.GEYSER && (level < 1 || level > 3)) {
             rv = false;
         } else if (type == Terrains.FORTIFIED && level != 1) {