Difference between revisions of "FF7/Coordinates encoding"
< FF7
Jump to navigation
Jump to search
my_wiki>FeuFeu |
my_wiki>FeuFeu |
||
| Line 13: | Line 13: | ||
* Y is an unsigned value ranging from 0 to 0x37FFF | * Y is an unsigned value ranging from 0 to 0x37FFF | ||
* Z is signed | * Z is signed | ||
| − | * Direction is multiplied by 0x10 after reading from save-game, but that's not affecting anything so we can think of it as a byte value. | + | * Direction is multiplied by 0x10 after reading from save-game, but that's not affecting anything so we can think of it as a byte value. e.g: 00: South, 40: East, 80: North, C0: West |
Revision as of 17:54, 7 April 2006
Coordinates on the world map are stored on 2 DWords and some basic decoding has to be done before you can manipulate them.
First DWord :
[1F 1E 1D 1C 1B 1A 19 18:17 16 15 14 13 12 11 10:0F 0E 0D 0C 0B 0A 09 08:07 06 05 04 03 02 01 00] | DIRECTION/0x10 | OBJECT'S ID | X COORDINATE OF THE OBJECT |
Second DWord :
[1F 1E 1D 1C 1B 1A 19 18:17 16 15 14 13 12 11 10:0F 0E 0D 0C 0B 0A 09 08:07 06 05 04 03 02 01 00] | Z COORDINATE OF THE OBJECT | Y COORDINATE OF THE OBJECT |
Notes :
- X is an unsigned value ranging from 0 to 0x47FFF
- Y is an unsigned value ranging from 0 to 0x37FFF
- Z is signed
- Direction is multiplied by 0x10 after reading from save-game, but that's not affecting anything so we can think of it as a byte value. e.g: 00: South, 40: East, 80: North, C0: West
| Value | Object |
|---|---|
| 0x00 | Party |
| 0x03 | Highwind |
| 0x05 | Tiny Bronco |
| 0x06 | Buggy |
| 0x0D | Submarine |
| 0x13 | Chocobo |
| 0x1D | Weapon |
How to decode coordinates in C
Assuming 1st and 2nd are respectively the first and second DWords :
X = 1st & 0x7FFFF Y = 2nd & 0x3FFFF Z = 2nd >> 0x12 // shift arithmetic right ID = (1st >> 0x13) & 0x1F DIR = (1st >> 0x14) & 0x0FF0
