Revision as of 08:04, 14 August 2006

For those familiar with TS1 modding, there is nothing new here. This page is designed primarily for the newcomer who does not have any previous experience with SimAntics.

Overview

This is by far the most used BHAV operation and, therefore, one of the first an aspiring behavioral modder should learn. At its heart, Expression is a fairly simple instruction, taking two items and performing a logical comparison or mathematical calculation with them.

Structure

The structure (with the exception of the as yet unknown bytes) is also fairly simple. We will use the following example instruction to explore the structure further:

aa, aa, bb, bb, ??, oo, AA, BB
xx, xx, xx, xx, xx, xx, xx, xx

Example:

00, 00, 00, 00, 00, 05, 19, 09
00, 00, 00, 00, 00, 00, 00, 00 

xx

unused

oo

the Operator, which tells the game which mathematical/logical operation to perform

AA

the first (or left-side) Operand

aa

argument for the first operand

BB

the second (or right-side) Operand

bb

argument for the second Operand

??

was never completely understood in TS1. Either it is some type of flag or is unused.

So in our example instruction:

• the Operator is 0x05 (assign to)
• the first Operand is 0x19 (local variable)
• which has an argument of 0x00 (numeric 0)
• the second Operand is 0x09 (parameter)
• which has an argument of 0x00 (numeric 0)

Our instruction would therefore be read as "local variable 0x0 := parameter 0x0". In simpler terms, this means "the value for local variable 0x0 := the value listed in parameter 0x0"

See also

• Primitives
• SimAntics

This article is imported from the old MTS2 wiki. It's original page, with comments, can be found at http://old_wiki.modthesims2.com/0x0002]