Author: HobbitDur
- Opcode: 0x0E4
- Short name: PREMAPJUMP
- Long name: Declare a scripted exit
Argument
none
Stack
Field Map ID
XCoord
YCoord
ZCoord
PREMAPJUMP
Description
Declares where a scripted exit leads, without jumping. On PC it has no effect on the game.
The handler looks for the first free record in the gateway table of the .inf loaded in memory (field ID 0x7FFF) and writes:
| Gateway value | Written value |
|---|---|
| Exit line point 1 X | XCoord |
| Exit line point 1 Y | YCoord |
| Exit line point 1 Z | ZCoord |
| Destination triangle | -1 |
| Destination field ID | Field Map ID |
| Next record’s field ID | 0x7FFF (the new end of table) |
The rest of the record keeps its old content. The opcode then continues with the next instruction (returns 2).
The record never fires: Field_Collision_CheckGatewayCrossing skips any gateway with triangle -1. Its only reader is Field_Collision_FindNearestGatewayDest, which runs every frame and stores the field ID of the gateway nearest to the player in FIELD_NEAREST_GATEWAY_FIELD_ID. Nothing in the PC executable reads that variable. The name and this “nearest exit” lookup suggest a hint for reading the next field ahead of time, but no such code exists on PC.
Use in the scripts
The retail scripts use it 790 times, in 252 fields. 757 of those are in line entities, 289 of them after a SETLINE in the same script. The destination usually matches a map jump in the same entity, so the script is declaring where its own exit leads.
| Destination | Uses |
|---|---|
| Same as a map jump of the same entity | 702 |
| Same as a map jump of another entity | 45 |
| Below 72 (world map, as for a gateway) | 38 |
| Neither | 5 |
Modding
The search for a free record has no limit. If the gateways of a field and its executed PREMAPJUMP total more than 12, the handler writes past the table into the door triggers and beyond. With 12 in total, the end marker alone lands on the Y of trigger 1’s first corner. The highest retail total is 10 (feart1f1 and bghall_1), counting one PREMAPJUMP per entity.
Records last until the next field load, because the .inf is reloaded.
PC handler: SCRIPT_PREMAPJUMP.
Function addresses
| Function | Address | Description |
|---|---|---|
SCRIPT_PREMAPJUMP | 0x521960 | Field script opcode handler |
Field_Collision_FindNearestGatewayDest | 0x47BD20 | Finds the nearest gateway each frame |
Field_Collision_CheckGatewayCrossing | 0x477980 | Fires gateways, skips triangle -1 |
FIELD_NEAREST_GATEWAY_FIELD_ID | 0x1CDC6E8 | Global variable, written and never read |
FIELD_INF_DATA_PTR | 0x1CDC744 | Global variable, pointer to the loaded .inf |