port Box_StalkBox

LostArtefacts · Apr 14, 2024 · ee33f84 · ee33f84
1 parent b5981f6
commit ee33f84
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Showing 6 changed files with 47 additions and 10 deletions.
diff --git a/docs/progress.svg b/docs/progress.svg
diff --git a/docs/progress.txt b/docs/progress.txt
@@ -1744,7 +1744,7 @@ typedef enum GAME_OBJECT_ID {
 0040E490    000001F3    +       int32_t __cdecl Box_SearchLOT(struct LOT_INFO *lot, int32_t expansion);
 0040E690    0000006F    +       int32_t __cdecl Box_UpdateLOT(struct LOT_INFO *lot, int32_t expansion);
 0040E700    00000095    +       void __cdecl Box_TargetBox(struct LOT_INFO *lot, int16_t box_num);
-0040E7A0    000000F2    -       int32_t __cdecl Box_StalkBox(struct ITEM_INFO *item, struct ITEM_INFO *enemy, int16_t box_num);
+0040E7A0    000000F2    +       int32_t __cdecl Box_StalkBox(struct ITEM_INFO *item, const struct ITEM_INFO *enemy, int16_t box_num);
 0040E8A0    000000A4    -       int32_t __cdecl Box_EscapeBox(struct ITEM_INFO *item, struct ITEM_INFO *enemy, int16_t box_num);
 0040E950    000000A7    -       int32_t __cdecl Box_ValidBox(struct ITEM_INFO *item, int16_t zone_num, int16_t box_num);
 0040EA00    0000043F    -       void __cdecl CreatureMood(struct ITEM_INFO *item, struct AI_INFO *info, int32_t violent);

diff --git a/src/game/box.c b/src/game/box.c
@@ -3,11 +3,13 @@
 #include "game/random.h"
 #include "global/const.h"
 #include "global/vars.h"
+#include "util.h"
 
 #define BOX_OVERLAP_INDEX 0x3FFF
 #define BOX_SEARCH_NUM 0x7FFF
 #define BOX_END_BIT 0x8000
 #define BOX_NUM_BITS (~BOX_END_BIT) // = 0x7FFF
+#define BOX_STALK_DIST 3 // tiles
 
 int32_t __cdecl Box_SearchLOT(
     struct LOT_INFO *const lot, const int32_t expansion)
@@ -129,3 +131,35 @@ void __cdecl Box_TargetBox(struct LOT_INFO *const lot, const int16_t box_num)
         lot->target.y = box->height;
     }
 }
+
+int32_t __cdecl Box_StalkBox(
+    const struct ITEM_INFO *const item, const struct ITEM_INFO *const enemy,
+    const int16_t box_num)
+{
+    const struct BOX_INFO *const box = &g_Boxes[box_num];
+
+    const int32_t z =
+        ((box->left + box->right) << (WALL_SHIFT - 1)) - enemy->pos.z;
+    const int32_t x =
+        ((box->top + box->bottom) << (WALL_SHIFT - 1)) - enemy->pos.x;
+
+    const int32_t x_range = (box->bottom - box->top + BOX_STALK_DIST)
+        << WALL_SHIFT;
+    const int32_t z_range = (box->right - box->left + BOX_STALK_DIST)
+        << WALL_SHIFT;
+    if (x > x_range || x < -x_range || z > z_range || z < -z_range) {
+        return false;
+    }
+
+    const int32_t enemy_quad = (enemy->rot.y >> 14) + 2;
+    const int32_t box_quad = (z > 0) ? ((x > 0) ? 2 : 1) : ((x > 0) ? 3 : 0);
+    if (enemy_quad == box_quad) {
+        return false;
+    }
+
+    const int32_t baddie_quad = item->pos.z > enemy->pos.z
+        ? (item->pos.x > x ? 2 : 1)
+        : (item->pos.x > x ? 3 : 0);
+
+    return enemy_quad == baddie_quad && ABS(enemy_quad - box_quad) == 2;
+}
diff --git a/src/game/box.h b/src/game/box.h
@@ -8,3 +8,6 @@
 int32_t __cdecl Box_SearchLOT(struct LOT_INFO *lot, int32_t expansion);
 int32_t __cdecl Box_UpdateLOT(struct LOT_INFO *lot, int32_t expansion);
 void __cdecl Box_TargetBox(struct LOT_INFO *lot, int16_t box_num);
+int32_t __cdecl Box_StalkBox(
+    const struct ITEM_INFO *item, const struct ITEM_INFO *enemy,
+    int16_t box_num);
diff --git a/src/global/funcs.h b/src/global/funcs.h
@@ -18,7 +18,6 @@
 #define Boat_Animation ((void __cdecl (*)(struct ITEM_INFO *boat, int32_t collide))0x0040D950)
 #define Boat_Control ((void __cdecl (*)(int16_t item_num))0x0040DAC0)
 #define Gondola_Control ((void __cdecl (*)(int16_t item_num))0x0040E0F0)
-#define Box_StalkBox ((int32_t __cdecl (*)(struct ITEM_INFO *item, struct ITEM_INFO *enemy, int16_t box_num))0x0040E7A0)
 #define Box_EscapeBox ((int32_t __cdecl (*)(struct ITEM_INFO *item, struct ITEM_INFO *enemy, int16_t box_num))0x0040E8A0)
 #define Box_ValidBox ((int32_t __cdecl (*)(struct ITEM_INFO *item, int16_t zone_num, int16_t box_num))0x0040E950)
 #define CreatureMood ((void __cdecl (*)(struct ITEM_INFO *item, struct AI_INFO *info, int32_t violent))0x0040EA00)

diff --git a/src/inject_exec.c b/src/inject_exec.c
@@ -525,6 +525,7 @@ static void Inject_Box(void)
     INJECT(1, 0x0040E490, Box_SearchLOT);
     INJECT(1, 0x0040E690, Box_UpdateLOT);
     INJECT(1, 0x0040E700, Box_TargetBox);
+    INJECT(1, 0x0040E7A0, Box_StalkBox);
 }
 
 static void Inject_Objects(void)