Z Bridge Format

Bridge records supplement the terrain cells of a Z map.

File format

The 312-byte file contains 12 records of 26 bytes (0x1a), loaded to static address 0xff3d4. Multi-byte values below are little-endian.

Offset	Data type	Name	Description
0	UINT16LE	x	Position; 0xffff is a free record.
2	UINT16LE	y	Position.
4	BYTE[8]	unknown	Preserve.
0x0c	UINT16LE	orientation selector	Zero/nonzero chooses the neighbouring cell checked during validation.
0x0e	BYTE	unknown	Preserve.
0x0f	BYTE	flags	Bit 2 is cleared by validation.
0x10	BYTE[2]	unknown	Preserve.
0x12	UINT8	timer parameter	0xff gives an unlimited sentinel; otherwise initialization multiplies by 17*100.
0x13	BYTE[6]	unknown	Preserve.
0x19	UINT8	state	Cleared by initialization.

Notes

Validation compares terrain codes 0x17 and 0x2b in map plane 1. An inconsistent bridge may be invalidated even if its record is well formed. The derived timer is written outside the disk record array; it is not another on-disk field.

Source code

From re-z, the open-source browser port:

• src/game/levelstate.js – fn2a497, fn2a451 and fn2a30e
• docs/re/NOTES.md – reverse-engineering notes and evidence status

Credits

This file format was reverse engineered by VorticonCmdr. If you find this information helpful in a project you're working on, please give credit where credit is due. (A link back to this wiki would be nice too!)