Custom Environmental Hazard Damage

src/mars_patcher/mf/auto_generated_types.py

@@ -513,6 +513,23 @@ class MarsschemamfCreditstextItem(typ.TypedDict, total=False):
 ]
 
 
+class MarsschemamfEnvironmentaldamage(typ.TypedDict):
+    Lava: Typeu8 = 20
+    """The amount of damage per second taken while submerged in lava."""
+
+    Acid: Typeu8 = 60
+    """The amount of damage per second taken while submerged in acid."""
+
+    Heat: Typeu8 = 6
+    """The amount of damage per second taken while in a heated environment."""
+
+    Cold: Typeu8 = 6
+    """The amount of damage per second taken while in a cold environment."""
+
+    Subzero: Typeu8 = 15
+    """The amount of damage per second taken while in Sub-Zero Containment. Currently unused, will always use Cold."""
+
+
 @typ.final
 class MarsschemamfLeveledits(typ.TypedDict, total=False):
     """Specifies the Room ID."""
@@ -633,6 +650,7 @@ class Marsschemamf(typ.TypedDict, total=False):
     DisableSoundEffects: bool = False
     """Disables all sound effects when true."""
 
+    EnvironmentalDamage: MarsschemamfEnvironmentaldamage
     MissileLimit: Typeu8 = 3
     """Changes how many missiles can be on-screen at a time. The vanilla game has it set to 2, the randomizer changes it to 3 by default. Zero Mission uses 4."""
 

src/mars_patcher/mf/constants/reserved_space.py

@@ -36,7 +36,7 @@ class ReservedPointersMF(IntEnum):
     STARTING_LOCATION_ADDR = auto()
     CREDITS_PARAMETERS_ADDR = auto()  # Unused. Remnant of when we didn't have looping credits music
     HINT_SECURITY_LEVELS_ADDR = auto()
-    ENVIRONMENTAL_HARZARD_DAMAGE_ADDR = auto()  # TODO: Implement this
+    ENVIRONMENTAL_HAZARD_DAMAGE_ADDR = auto()
     MISSILE_LIMIT_ADDR = auto()
     ROOM_NAMES_TABLE_ADDR = auto()
     REVEAL_HIDDEN_TILES_ADDR = auto()

src/mars_patcher/mf/data/schema.json

@@ -586,6 +586,37 @@
             "description": "Disables all sound effects when true.",
             "default": false
         },
+        "EnvironmentalDamage": {
+            "type": "object",
+            "properties": {
+                "Lava": {
+                    "$ref": "#/$defs/TypeU8",
+                    "description": "The amount of damage per second taken while submerged in lava.",
+                    "default": 20
+                },
+                "Acid": {
+                    "$ref": "#/$defs/TypeU8",
+                    "description": "The amount of damage per second taken while submerged in acid.",
+                    "default": 60
+                },
+                "Heat": {
+                    "$ref": "#/$defs/TypeU8",
+                    "description": "The amount of damage per second taken while in a heated environment.",
+                    "default": 6
+                },
+                "Cold": {
+                    "$ref": "#/$defs/TypeU8",
+                    "description": "The amount of damage per second taken while in a cold environment.",
+                    "default": 6
+                },
+                "Subzero": {
+                    "$ref": "#/$defs/TypeU8",
+                    "description": "The amount of damage per second taken while in Sub-Zero Containment. Currently unused, will always use Cold.",
+                    "default": 15
+                }
+            },
+            "required": ["Lava", "Acid", "Heat", "Cold", "Subzero"]
+        },
         "MissileLimit": {
             "$ref": "#/$defs/TypeU8",
             "description": "Changes how many missiles can be on-screen at a time. The vanilla game has it set to 2, the randomizer changes it to 3 by default. Zero Mission uses 4.",

src/mars_patcher/mf/misc_patches.py

@@ -1,4 +1,5 @@
 import mars_patcher.constants.game_data as gd
+from mars_patcher.mf.auto_generated_types import MarsschemamfEnvironmentaldamage
 from mars_patcher.mf.constants.reserved_space import ReservedPointersMF
 from mars_patcher.mf.data import get_data_path
 from mars_patcher.patching import BpsDecoder, IpsDecoder
@@ -85,6 +86,20 @@ def apply_alternative_health_layout(rom: Rom) -> None:
     rom.write_8(rom.read_ptr(ReservedPointersMF.USE_ALTERNATIVE_HUD_DISPLAY.value), 1)
 
 
+def apply_environmental_damage(rom: Rom, damage_dict: MarsschemamfEnvironmentaldamage) -> None:
+    base_address = rom.read_ptr(ReservedPointersMF.ENVIRONMENTAL_HAZARD_DAMAGE_ADDR.value)
+    damage = [
+        damage_dict["Lava"],
+        damage_dict["Acid"],
+        damage_dict["Heat"],
+        # ASM currently has Subzero and Cold mislabelled. https://github.com/MetroidAdvRandomizerSystem/mars-fusion-asm/issues/374
+        damage_dict["Cold"],
+        damage_dict["Subzero"],
+    ]
+    for offset, damage_amount in enumerate(damage):
+        rom.write_8(base_address + offset, damage_amount)
+
+
 def apply_reveal_hidden_tiles(rom: Rom) -> None:
     rom.write_8(rom.read_ptr(ReservedPointersMF.REVEAL_HIDDEN_TILES_ADDR.value), 1)
 

src/mars_patcher/mf/patcher.py

@@ -18,6 +18,7 @@
     apply_accessibility_patch,
     apply_alternative_health_layout,
     apply_base_patch,
+    apply_environmental_damage,
     apply_instant_unmorph_patch,
     apply_nerf_gerons,
     apply_reveal_hidden_tiles,
@@ -151,6 +152,9 @@ def patch_mf(
     if patch_data.get("DisableSoundEffects"):
         disable_sound_effects(rom)
 
+    if environmental_damage := patch_data.get("EnvironmentalDamage"):
+        apply_environmental_damage(rom, environmental_damage)
+
     if "MissileLimit" in patch_data:
         change_missile_limit(rom, patch_data["MissileLimit"])