Decomped IsTargetStraightAhead()

1 files changed, 77 insertions, 0 deletions

diff --git a/src/dungeon_ai_attack.c b/src/dungeon_ai_attack.c
new file mode 100644
index 0000000..48ccdfe
--- /dev/null
+++ b/src/dungeon_ai_attack.c
@@ -0,0 +1,77 @@
+#include "global.h"
+#include "dungeon_ai_attack.h"
+
+#include "constants/iq_skill.h"
+#include "dungeon_global_data.h"
+#include "dungeon_map_access.h"
+#include "dungeon_pokemon_attributes_1.h"
+
+extern struct Position gAdjacentTileOffsets[8];
+
+bool8 IsTargetStraightAhead(struct DungeonEntity *pokemon, struct DungeonEntity *targetPokemon, s32 facingDir, s32 maxRange)
+{
+    s32 posDiffX = pokemon->posWorld.x - targetPokemon->posWorld.x;
+    s32 effectiveMaxRange;
+    if (posDiffX < 0)
+    {
+        posDiffX = -posDiffX;
+    }
+    effectiveMaxRange = pokemon->posWorld.y - targetPokemon->posWorld.y;
+    if (effectiveMaxRange < 0)
+    {
+        effectiveMaxRange = -effectiveMaxRange;
+    }
+    if (effectiveMaxRange < posDiffX)
+    {
+        effectiveMaxRange = posDiffX;
+    }
+    if (effectiveMaxRange > maxRange)
+    {
+        effectiveMaxRange = maxRange;
+    }
+    if (!HasIQSkill(pokemon, IQ_SKILL_COURSE_CHECKER))
+    {
+        // BUG: effectiveMaxRange is already capped at maxRange, so this condition always evaluates to TRUE.
+        // The AI also has range checks elsewhere, so this doesn't become an issue in most cases.
+        // If the AI has the Long Toss or Pierce statuses and Course Checker is disabled,
+        // this incorrect check causes the AI to throw items at targets further than 10 tiles away.
+        if (effectiveMaxRange <= maxRange)
+        {
+            return TRUE;
+        }
+    }
+    else
+    {
+        s32 currentPosX = pokemon->posWorld.x;
+        s32 currentPosY = pokemon->posWorld.y;
+        s32 adjacentTileOffsetX = gAdjacentTileOffsets[facingDir].x;
+        s32 adjacentTileOffsetY = gAdjacentTileOffsets[facingDir].y;
+        s32 i;
+        for (i = 0; i <= effectiveMaxRange; i++)
+        {
+            struct MapTile *mapTile;
+            currentPosX += adjacentTileOffsetX;
+            currentPosY += adjacentTileOffsetY;
+            if (currentPosX <= 0 || currentPosY <= 0 ||
+                currentPosX >= DUNGEON_MAX_SIZE_X - 1 || currentPosY >= DUNGEON_MAX_SIZE_Y - 1)
+            {
+                break;
+            }
+            while (0); // Extra label needed to swap branch locations in ASM.
+            mapTile = GetMapTileAtPosition(currentPosX, currentPosY);
+            if (!(mapTile->tileType & (TILE_TYPE_FLOOR | TILE_TYPE_LIQUID)))
+            {
+                break;
+            }
+            if (mapTile->pokemon == targetPokemon)
+            {
+                return TRUE;
+            }
+            if (mapTile->pokemon != NULL)
+            {
+                break;
+            }
+        }
+    }
+    return FALSE;
+}