Operator Element

Property Elements are a subgroup of the elements in the Oblivion XML schema, always found as children of Property Elements. They are used to create mathematical formulas, which the game engine can evaluate to obtain a value for the parent property.

There is, generally speaking, an Operator Element for every basic binary mathematical operator - every operator that takes exactly two operands. The first operand is always the current value of the property, and the second is the contents of the operator. For example:

<image>
  <x>
    <add> 1 </add>  <!-- Add one to current x position -->
  </x>
</image>

A property element may contain a series of Operators, which are evaluated in order:

<image>
  <x>
    <!-- New X = (X + 10) * 2 -->
    <add> 10 </add>
    <mult> 2 </mult> 
  </x>
</image>

Operator Elements may contain other operator elements as children:

<image>
  <x>
    <!-- New X = X + (10 / 3) -->
    <add> 
      <copy> 10 </copy>
      <div> 3 </div>
    </add>
  </x>
</image>

Operator Elements may contain the value of a property for some other element somewhere in the menu:

<image>
  <x>
    <!-- Place this image 10 pixels to the right of the "ExitButton" element -->
    <copy src="ExitButton" trait="x"/>
    <add src="ExitButton" trait="width"/>
    <add> 10 </add>
  </x>
</image>

Copy Operator

The only unary (single-operand) operator. The <copy> operator replaces the current property value with its contents:

<image>
  <x>
     <!-- Set the current x position to be 50 pixels -->
     <Copy> 50 </Copy>
  </x>
</image>

Algebraic Operators

These should be self-explanatory.

• Add
• Sub
• Mult/Mul - different elements, but both perform exactly the same function.
• Div - floating point, rather than integer, division

Boolean Operators

• Onlyif
• Onlyifnot
• Lt
• Gt
• Eq
• Neq
• Min
• Max