OpenSim.Region.ScriptEngine.DotNetEngine

Revision as of 08:46, 29 August 2007

DotNetEngine

Namespace: OpenSim.Region.ScriptEngine.DotNetEngine

DotNetEngine is a ScriptEngine that executes LSL scripts contained within objects.
Core development blog: [1]

To look at the LSL command implementation status, go to llFunction implementation status.

How it works

• Create instance of ScriptEngine(scene).
  
• ScriptEngine will create instances of:
  

EventManager
EventQueueManager
ScriptManager
AppDomainManager
LSLLongCmdHandler

• EventManager will hook up all necessary events. (all possible script events, script rez, script derez, etc)
  
• When events are received, they are processed inside EventManager.
  

For example:
Event for loading a script will be processed and EventManager will tell ScriptManager to load the script.
Event such as touch_start is received in EventManager then sent to EventQueueManager that will tell SCriptManager to execute the touch_start function in the script.

Note! If event is for a particular object, EventQueueManager will queue event for all scripts inside that object.

• If it is a script rez then OpenSim.Region.ScriptEngine.DotNetEngine.Compiler.LSL will compile the script to .Net Assembly.
  
• This assembly is loaded into an AppDomain created by AppDomainManager.
  
• EventQueueManager has a separate thread running to process its event queue. Events are actually functions inside the script .dll that is called "<state>_event_<event_name>" for example "default_event_touch_start". State is read from a global variable in the script .dll.
  
• Some commands requires more time before returning, processing these is done in LSLLongCmdHandler.
  
• Every script receives a private instance of LSL_BuiltIn_Commands. This is their only way of manipulating anything outside themselves.
  

Places to extend script support

• LSL_BuiltIn_Commands.cs

These are the functions script can use to manipulate the scene. Commonly known as ll-functions. They are LSL functions such as llSay, llWhisper, etc. The page llFunction implementation status contains up to date status on what functions has been implemented. Anyone who wants to contribute can implement a command and put a patch on the [http://bug.openmv.org/main_page.php bug tracker}.

• EventManager.cs

This is where events are coming from server and being queued for scripts. All 16 or so LSL events needs to be implemented here.

This image is a bit (not much) outdated, but gives you an idea of the path script events/functions go through.