tiny-ecs

Contents

• Filter functions
• System functions
• World functions

Modules

• tiny-ecs

Module tiny-ecs

Info:

• Author: Calvin Rose

Filter functions

tiny.requireAll (...)	Makes a Filter that filters Entities with specified Components.
tiny.requireOne (...)	Makes a Filter that filters Entities with specified Components.

System functions

tiny.processingSystem (table)	Creates a Processing System.
tiny.system (table)	Creates a System.

World functions

tiny.activate (world, ...)	Activates Systems in the World.
tiny.add (world, ...)	Shortcut for adding multiple Entities and Systems to the World.
tiny.addEntity (world, entity)	Adds an Entity to the world.
tiny.addSystem (world, system)	Adds a System to the world.
tiny.clearEntities (world)	Removes all Entities from the World.
tiny.clearSystems (world)	Removes all Systems from the World.
tiny.deactivate (world, ...)	Deactivates Systems in the World.
tiny.getEntityCount (world)	Gets count of Entities in World.
tiny.getSystemCount (world)	Gets count of Systems in World.
tiny.getSystemIndex (world, system)	Gets the index of a System in the world.
tiny.manageEntities (world)	Adds and removes Entities that have been marked.
tiny.manageSystems (world)	Adds and removes Systems that have been marked from the World.
tiny.remove (world, ...)	Shortcut for removing multiple Entities and Systems from the World.
tiny.removeEntity (world, entity)	Removes an Entity to the World.
tiny.removeSystem (world, system)	Removes a System from the world.
tiny.setSystemIndex (world, system, index)	Sets the index of a System in the world.
tiny.update (world, dt)	Updates the World.
tiny.updateSystem (world, system, dt)	Updates a System.
tiny.world (...)	Creates a new World.

Filter functions

A Filter is a function that selects which Entities apply to a System.

tiny.requireAll (...)

Makes a Filter that filters Entities with specified Components. An Entity must have all Components to match the filter.

Parameters:

• ... List of Components

tiny.requireOne (...)

Makes a Filter that filters Entities with specified Components. An Entity must have at least one specified Component to match the filter.

Parameters:

• ... List of Components

System functions

A System is a wrapper around function callbacks for manipulating Entities.

tiny.processingSystem (table)

Creates a Processing System. A Processing System iterates through its Entities in no particluar order, and updates them individually. It has two important fields, function system:process(entity, dt), and function system:filter(entity). entities is an unordered table of Entities with Entities as KEYS, and dt is the delta time. There are also a few other optional callbacks: function system:preProcess(entities, dt) - returns nil, function system:postProcess(entities, dt) - returns nil, function system:onAdd(entity) - returns nil, function system:onRemove(entity) - returns nil. For Filters, it is conveient to use tiny.requireAll or tiny.requireOne, but one can write their own filters as well.

Parameters:

• table A table to be used as a System, or nil to create a new Processing System.

tiny.system (table)

Creates a System. Systems are tables that contain at least one field; an update function that takes parameters like so: function system:update(entities, dt). entities is an unordered table of Entities with Entities as KEYS, and dt is the delta time. There are also a few other optional callbacks: function system:filter(entity) - returns a boolean, function system:onAdd(entity) - returns nil, function system:onRemove(entity) - returns nil. For Filters, it is conveient to use tiny.requireAll or tiny.requireOne, but one can write their own filters as well.

Parameters:

• table A table to be used as a System, or nil to create a new System.

World functions

A World is a container that manages Entities and Systems. The tiny-ecs module is set to be the __index of all World tables, so the often clearer syntax of World:method can be used for any function in the library. For example, tiny.add(world, e1, e2, e3) is the same as world:add(e1, e2, e3).

tiny.activate (world, ...)

Activates Systems in the World. Activated Systems will be update whenever tiny.update(world, dt) is called.

Parameters:

• world
• ... Systems to activate. The Systems must already be added to the World.

tiny.add (world, ...)

Shortcut for adding multiple Entities and Systems to the World. New objects will enter the World the next time World:update(dt) is called. Also call this method when an Entity has had its Components changed, such that it matches different Filters.

Parameters:

• world
• ... Systems and Entities

tiny.addEntity (world, entity)

Adds an Entity to the world. The new Entity will enter the world next time World:update is called. Also call this on Entities that have changed Components such that it matches different systems.

Parameters:

• world
• entity

tiny.addSystem (world, system)

Adds a System to the world. The new System will enter the world next time World:update is called.

Parameters:

• world
• system

tiny.clearEntities (world)

Removes all Entities from the World. When World:update(dt) is next called, all Entities will be removed.

Parameters:

• world

tiny.clearSystems (world)

Removes all Systems from the World. When World:update(dt) is next called, all Systems will be removed.

Parameters:

• world

tiny.deactivate (world, ...)

Deactivates Systems in the World. Deactivated Systems must be update manually, and will not update when the rest of World updates. They will, however, process new Entities added while the System is deactivated.

Parameters:

• world
• ... Systems to deactivate. The Systems must already be added to the World.

tiny.getEntityCount (world)

Gets count of Entities in World.

Parameters:

• world

tiny.getSystemCount (world)

Gets count of Systems in World.

Parameters:

• world

tiny.getSystemIndex (world, system)

Gets the index of a System in the world. Lower indexed Systems are processed before higher indexed systems.

Parameters:

• world
• system

tiny.manageEntities (world)

Adds and removes Entities that have been marked. The user of this library should seldom if ever call this.

Parameters:

• world

tiny.manageSystems (world)

Adds and removes Systems that have been marked from the World. The user of this library should seldom if ever call this.

Parameters:

• world

tiny.remove (world, ...)

Shortcut for removing multiple Entities and Systems from the World. Objects will exit the World the next time World:update(dt) is called.

Parameters:

• world
• ... Systems and Entities

tiny.removeEntity (world, entity)

Removes an Entity to the World. The Entity will exit the World next time World:update is called. Also call this on Entities that have changed Components such that it matches different systems.

Parameters:

• world
• entity

tiny.removeSystem (world, system)

Removes a System from the world. The System will exit the World next time World:update is called.

Parameters:

• world
• system

tiny.setSystemIndex (world, system, index)

Sets the index of a System in the world. Changes the order in which they Systems processed, because lower indexed Systems are processed first.

Parameters:

• world
• system
• index

tiny.update (world, dt)

Updates the World. Frees Entities that have been marked for freeing, adds entities that have been marked for adding, etc.

Parameters:

• world
• dt Delta time

tiny.updateSystem (world, system, dt)

Updates a System.

Parameters:

• world
• system A System in the World to update
• dt Delta time

tiny.world (...)

Creates a new World. Can optionally add default Systems and Entities.

Parameters:

• ... Systems and Entities to add to the World

Returns:

A new World