DaBes Scripting

• Index

Contents

• Properties
• Class Methods
• Configuration
• Hooks
• Helpers

Modules

• body
• bound_object
• camera
• canvas
• collection
• controller
• easer
• entity
• music
• net
• net_match
• object
• overlay
• parallax
• parallax_layer
• recorder
• scene
• scene_manager
• sensor
• sfx
• shape
• shape_matcher
• sprite
• sprite_animation
• step_sequencer
• util

Module bound_object

Some weird meta stuff that lets us create a nice object oriented interface around the C bindings.

This is mostly used internally, but the init hook is useful for custom objects.

BoundObject extends Object

Properties

real	The userdata that represents an instance inside of the game engine.

Class Methods

BoundObject:new (...)

Create a new instance of BoundObject.

Configuration

lib	The Lua library provided by the game engine that instance method calls are forwarded to.
_collections	A table of collection configurations for the class.

Hooks

realize (self, ...)	Responsible for interacting with the lib and returning a userdata.
init (self, ...)	Called immediately after realize .

Helpers

BoundObject.fwd_func (name)	Generate a method that performs one-to-one argument forwarding to lib
BoundObject.fwd_func_real (name)	Generate a method that performs one-to-one argument forwarding, replacing each argument with arg.real
BoundObject.fwd_func_opts (name, keys, defaults)	Generate a method that performs key-mapped argument forwarding.
BoundObject.fwd_adder (name)	Generate a lib forwarded method intended to add an object to a collection.
BoundObject.fwd_remover (name)	Generate a lib forwarded method intended to remove an object from a collection.
BoundObject.fwd_zeroing_setter (fname, pname)	Generate a lib forwarded setter that enables the corresponding property to be set to nil by the game engine.
BoundObject.readonly ()	A function that throws a "read only" error, intended for setter forwarding.

Properties

Properties. Significant fields on an instance.

real

The userdata that represents an instance inside of the game engine.

Class Methods

Class Methods. Must be called on Class, with a capital leading character. e.g. Class:method("foo")

BoundObject:new (...)

Create a new instance of BoundObject.

This is the external method used to create a bound object. It calls the realize hook, then the init hook.

new should not be overloaded by a subclass. Implement the init hook if you want to perform actions when the object is created.

Parameters:

• ... Constructor parameters. These are sent to realize and init

Returns:

BoundObject A new instance of BoundObject

Configuration

Configuration. Required by subclass declarations. Used when instantiating concrete subclasses.

lib

The Lua library provided by the game engine that instance method calls are forwarded to.

_collections

A table of collection configurations for the class.

Hooks

Hooks. Callbacks implemented in subclasses to customize behavior. Hooks are called on individual instances.

realize (self, ...)

Responsible for interacting with the lib and returning a userdata.

This hook is required. A BoundObject will not function without an implementation of realize .

Parameters:

• self BoundObject An instance in the throws of instantiation
• ... Any arguments passed to new

Returns:

userdata The userdata that will be set to real

init (self, ...)

Called immediately after realize .

This is only called once in the BoundObject's lifecycle.

Parameters:

• self BoundObject The realized instance
• ... Any arguments passed to new

Helpers

Helpers. Utility functions stored on a class. Called using dot syntax. e.g. Class.helper("foo")

BoundObject.fwd_func (name)

Generate a method that performs one-to-one argument forwarding to lib

Parameters:

• name string The name of the lib function

Returns:

function

BoundObject.fwd_func_real (name)

Generate a method that performs one-to-one argument forwarding, replacing each argument with arg.real

Parameters:

• name string The name of the lib function

Returns:

function

BoundObject.fwd_func_opts (name, keys, defaults)

Generate a method that performs key-mapped argument forwarding.

This will generate a method that accepts one argument, an opts table.

The values of the opts table are sent to the lib function specified by name. They are arranged in the order that the table keys appear in the keys list. Any keys not specified in the keys list are ignored.

Parameters:

• name string The name of the lib function
• keys table The ordered list of keys to be mapped to the lib function
• defaults table An optional defaults table

Returns:

function

BoundObject.fwd_adder (name)

Generate a lib forwarded method intended to add an object to a collection.

This performs some caching in the Lua VM so added objects don't get collected by the GC.

Parameters:

• name string The name of the lib function

Returns:

function

BoundObject.fwd_remover (name)

Generate a lib forwarded method intended to remove an object from a collection.

This performs some caching in the Lua VM so removed objects can get collected by the GC.

Parameters:

• name string The name of the lib function

Returns:

function

BoundObject.fwd_zeroing_setter (fname, pname)

Generate a lib forwarded setter that enables the corresponding property to be set to nil by the game engine.

This implements an ad-hoc hook called _zero which is called by the engine when the object has been destroyed. An example of this behavior is how a ${music|Music} instance is destroyed when it is finished playing.

Parameters:

• fname string The name of the lib function
• pname string The name of the corresponding property

Returns:

function

BoundObject.readonly ()

A function that throws a "read only" error, intended for setter forwarding.

Returns:

function