tr2/objects/bird_guardian: remove hard-coded end level behaviour

This removes the hard-coded end level behaviour of the bird guardian in
TR2. For OG, an injection is provided to add a command to the death
animation to yield the same result; custom levels can modify the object
accordingly externally.

Resolves #1583.

data/tr2/ship/cfg/TR2X_gameflow.json5

@@ -309,6 +309,7 @@
             ],
             "injections": [
                 "data/injections/common_pickup_meshes.bin",
+                "data/injections/guardian_death_commands.bin",
                 "data/injections/palace_fd.bin",
                 "data/injections/palace_itemrots.bin",
             ],

data/tr2/ship/cfg/TR2X_gameflow_gm.json5

@@ -106,6 +106,9 @@
                 {"type": "total_stats", "background_path": "data/images/end.png"},
                 {"type": "level_complete"},
             ],
+            "injections": [
+                "data/injections/guardian_death_commands.bin",
+            ],
         },
 
         // 5. Nightmare in Vegas
@@ -124,6 +127,9 @@
                 {"type": "level_stats"},
                 {"type": "level_complete"},
             ],
+            "injections": [
+                "data/injections/guardian_death_commands.bin",
+            ],
         },
     ],
 

docs/GAME_FLOW.md

@@ -1376,7 +1376,22 @@ provided with the game achieves.
 
 #### TR2
 
-TBD
+<table>
+  <tr valign="top" align="left">
+    <th>Injection file</th>
+    <th>Purpose</th>
+  </tr>
+  <tr valign="top">
+    <td>
+      <code>guardian_death_commands.bin</code>
+    </td>
+    <td>
+      Injects an animation command for the bird guardian to end the level on the
+      final frame of its death animation. The original hard-coded end-level
+      behaviour is removed in TR2X.
+    </td>
+  </tr>
+</table>
 
 ## FMVs
 

docs/tr2/CHANGELOG.md

@@ -15,6 +15,7 @@
 - fixed the console opening when remapping its key (#2641)
 - fixed sprites rendering black if no shade value is assigned in the level (#2701, regression from 0.8)
 - removed the need to specify in the game flow levels that have no secrets (secrets will be automatically counted) (#1582)
+- removed the hard-coded end-level behaviour of the bird guardian for custom levels (#1583)
 
 ## [0.10](https://github.com/LostArtefacts/TRX/compare/tr2-0.9.2...tr2-0.10) - 2025-03-18
 - added support for 60 FPS rendering

docs/tr2/README.md

@@ -308,6 +308,7 @@ as Notepad.
 - added developer console (accessible with `/`, see [COMMANDS.md](COMMANDS.md) for details)
 - added ability to disable FMVs
 - added per-level customizable fog distance
+- removed the hard-coded end-level behaviour of the bird guardian for custom levels
 
 #### Miscellaneous
 - added Linux builds

src/tr2/game/objects/creatures/bird_guardian.c

@@ -17,7 +17,6 @@
 #define BIRD_GUARDIAN_ATTACK_1_RANGE SQUARE(WALL_L) // = 1048576
 #define BIRD_GUARDIAN_ATTACK_2_RANGE SQUARE(WALL_L * 2) // = 4194304
 #define BIRD_GUARDIAN_PUNCH_DAMAGE   200
-#define BIRD_GUARDIAN_DEATH_FRAME    158
 // clang-format on
 
 typedef enum {
@@ -187,15 +186,9 @@ static void M_Control(const int16_t item_num)
         default:
             break;
         }
-    } else {
+    } else if (item->current_anim_state != BIRD_GUARDIAN_STATE_DEATH) {
-        if (item->current_anim_state != BIRD_GUARDIAN_STATE_DEATH) {
+        Item_SwitchToAnim(item, BIRD_GUARDIAN_ANIM_DEATH, 0);
-            Item_SwitchToAnim(item, BIRD_GUARDIAN_ANIM_DEATH, 0);
+        item->current_anim_state = BIRD_GUARDIAN_STATE_DEATH;
-            item->current_anim_state = BIRD_GUARDIAN_STATE_DEATH;
-        }
-
-        if (Item_TestFrameEqual(item, BIRD_GUARDIAN_DEATH_FRAME)) {
-            g_LevelComplete = true;
-        }
     }
 
     Creature_Head(item, head);