add BB stack limits patch

2024-08-10 00:29:24 -07:00
parent d676e9bb38
commit f0366a3550
6 changed files with 128 additions and 5 deletions
@@ -0,0 +1,87 @@
+# It would be a bad idea to remove `.meta hide_from_patches_menu` to make this
+# patch an option for players to be able to select; either all players on the
+# server should have this patch, or none should have it.
+
+# If you change the stack limits in config.json away from the defaults, you
+# should change the limits array below to match config.json and add this patch
+# to the BBRequiredPatches list.
+
+.meta name="Item stacks"
+.meta description=""
+.meta hide_from_patches_menu
+
+entry_ptr:
+reloc0:
+  .offsetof start
+start:
+  .include  WriteCodeBlocksBB
+
+  # Patch 1: rewrite item_is_stackable
+  .data     0x005C502C
+  .deltaof  item_is_stackable_start, item_is_stackable_end
+
+item_is_stackable_start:
+  mov       eax, [esp + 4]
+  cmp       al, 4
+  je        return_1
+
+  cmp       al, 3
+  jne       return_0
+
+  mov       ah, [esp + 8]
+  push      eax
+  mov       ecx, esp
+
+  .binary   E8EC130100  # call max_stack_size_for_tool_start
+  pop       ecx
+  cmp       eax, 1
+  jg        return_1
+  # Fallthrough to return_0
+
+return_0:
+  xor       eax, eax
+  ret
+return_1:
+  xor       eax, eax
+  inc       eax
+  ret
+item_is_stackable_end:
+
+  # Patch 2: rewrite max_stack_size_for_tool
+  .data     0x005D6430
+  .deltaof  max_stack_size_for_tool_start, max_stack_size_for_tool_end
+
+max_stack_size_for_tool_start:
+  xor       eax, eax
+  inc       eax
+
+  # if (data1[0] != 3) return 1
+  cmp       byte [ecx], 3
+  jne       not_tool2
+
+  # declare return values array
+  call   data_end
+  # This array specifies the stack limits for each tool class. The array index
+  # is the second byte of the item data (see names-v4.json for the values; for
+  # e.g. tech disks this would be 02). For classes beyond 15, the value for 15
+  # is used.
+  # Index:  00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15
+  .binary   0A 0A 01 0A 0A 0A 0A 0A 0A 01 63 63 01 01 01 01 63 01 01 01 01 01
+data_end:
+
+  # eax = min<uint8_t>(data1[1], 0x11)
+  mov       al, [ecx + 1]
+  xor       edx, edx
+  mov       dl, 0x11
+  cmp       eax, edx
+  cmovg     eax, edx
+
+  # return data[eax]
+  pop       edx
+  mov       al, [edx + eax]
+not_tool2:
+  ret
+max_stack_size_for_tool_end:
+
+  .data     0x00000000
+  .data     0x00000000