View source for Animation-CobOverview

==What is COB?==

COB is the Spring engine's scripting system. Each unit has a .cob bitfile which defines many of its major behaviors, including animation and weapon aiming. Of course, COB is also capable of doing a lot more if you wish. When Spring is actually running, it interprets the bitfile for each unit as necessary. This interpreter runs in a very straightforward way, without any fancy optimizations, so don't expect great performance from it.

==BOS==

The code that gets compiled into a .cob is written in a .bos file. A program called [[Map,_Game,_And_Unit_Development_Programs#Scripting_And_Unit_Stats_files|Scriptor]] generally does this compilation. BOS uses a C-like syntax, although it has many Spring-specific features and isn't as powerful as C.

===BOS versus C===

Similarities:
*Function syntax. A function is defined by FunctionName(args).
*Block delimiters. Like C, a statement block is delimited by curly braces ({}).
*General syntax. For example, to add two variables and assign the result to a third, you say x = y + z;

Differences:
*Not case sensitive.
*Only one data type. There is only one type of data in COB, which is basically a 32-bit integer.
*Variable declaration. 

You can declare a static variable, whose scope encompasses the entire script, using

 static-var x;

You can declare multiple variables at once by separating them with commas.

Alternately, you can declare a local variable:

 var x;

The scope is limited to the function that it is in.
*No pointers or arrays.
*No internal return values. When the script receives a callin, it may return a value to the "outside"; however, there is no way to return a value directly to another function within the script. You will have to use a static variable.
*Function calls. 

Functions are called using

 call-script Function(args);

or 

 start-script Function(args);

See [[Animation-CobThreads|COB-Threads]] for details.
*Multiple threads. This isn't as exciting as it sounds. Again, see [[Animation-CobThreads|COB-Threads]] for details.
*Spring-specific features. There are too many here to name; please consult the other COB articles.

==Further information==
Greater detail can be found on the following pages
*[[Animation-CobAnimation]]
*[[Animation-CobCallins]]
*[[Animation-CobConstants]]
*[[Animation-CobHitByWeaponID]]

[[Category:Animation]]