bcdfp — Game Logic

bcdfp — Game Logic

bcdfp (23,960 bytes) is the HUNK overlay that contains all the 3D rendering, blitter routines, game logic, and the item/class tables. It’s the code overlay — the one that actually draws the dungeon.

What it holds

• The VBlank handler (LAB_00D3) that drives the 3D viewport rendering pipeline, dispatching through a jump table to per-direction renderers.
• The main sprite blitter (LAB_011E) — the cookie-cut mask + colour renderer used everywhere.
• The text rendering blitter (LAB_0103).
• The UI descriptor table (LAB_010D) that drives bcdfo’s UI elements.
• The item table and class definitions in its DATA section.
• The character-creation screen layout table.
• The BCSub message-port setup.
• The character record layout (168 bytes per character, 4 characters).

The character record (from the WHDLoad trainer)

Each character is 0xA8 (168) bytes, 4 characters, base $1758(A5):

Offset	Field
+0x00	name
+0x4E	current HP (w)
+0x50	max HP (w)
+0x52	experience (l)
+0x56	gold (w)
+0x64–68	current STR/INT/WIS/CON/CHR (b)
+0x6E–72	max STR/INT/WIS/CON/CHR (b)
+0xA2	level/XP (w)

A note on the disassembly

Much of the monster-sprite rendering code lives in inline raw data blocks that IRA couldn’t disassemble (encoded as DC.L). The rendering pipeline was reconstructed from the surrounding structure and the blitter conventions — see blitter & minterms.