shithub: zelda3

Info  •  Files  •  Log  •  Branches

Workaround a possible zelda chest minigame bug (Related to #113)

 - It reads from index 0x14a4 of the chest array...?

--- a/dungeon.c

+++ b/dungeon.c

@@ -5842,24 +5842,23 @@

   *chest_position = pos * 2;

-  WORD(dung_bg2_attr_table[pos]) = 0x202;

-  WORD(dung_bg2_attr_table[pos + 64]) = 0x202;

+  WORD(dung_bg2_attr_table[pos + XY(0, 0)]) = 0x202;

+  WORD(dung_bg2_attr_table[pos + XY(0, 1)]) = 0x202;

-  pos += XY(0, 2);

-

   const uint16 *src = SrcPtr(0x14A4);

-  dung_bg2[pos + XY(0, 0)] = src[0];

-  dung_bg2[pos + XY(0, 1)] = src[1];

-  dung_bg2[pos + XY(1, 0)] = src[2];

-  dung_bg2[pos + XY(1, 1)] = src[3];

-  uint16 yy = 0x14A4; // wtf

+  int pos_wrong = pos + XY(0, 2);  // zelda bug?

+  dung_bg2[pos_wrong + XY(0, 0)] = src[0];

+  dung_bg2[pos_wrong + XY(0, 1)] = src[1];

+  dung_bg2[pos_wrong + XY(1, 0)] = src[2];

+  dung_bg2[pos_wrong + XY(1, 1)] = src[3];

+  // The orig asm code seems to access invalid vram here because it indexes by 0x14a4

   uint16 *dst = &vram_upload_data[vram_upload_offset >> 1];

-  dst[0] = RoomTag_BuildChestStripes((pos + 0) * 2, yy);

-  dst[3] = RoomTag_BuildChestStripes((pos + 64) * 2, yy);

-  dst[6] = RoomTag_BuildChestStripes((pos + 1) * 2, yy);

-  dst[9] = RoomTag_BuildChestStripes((pos + 65) * 2, yy);

+  dst[0] = Dungeon_MapVramAddr(pos + 0);

+  dst[3] = Dungeon_MapVramAddr(pos + 64);

+  dst[6] = Dungeon_MapVramAddr(pos + 1);

+  dst[9] = Dungeon_MapVramAddr(pos + 65);

   dst[2] = src[0];

   dst[5] = src[1];