Lua

Events

Functions	Description
shiva.dispatcher:trigger_[event_name]_event	trigger an event with the c++ dispatcher

Entity Registry

Functions	Description
shiva.entity_registry:create	create an entity.
shiva.entity_registry:destroy	destroy an entity
shiva.entity_registry:nb_entities	get the numbers of entities
shiva.entity_registry:has_[component_name]_component	checks whether the requested component is associated with the given entity

Events API Documentation

shiva.dispatcher:trigger_[event_name]_event

This function trigger an event using the EnTT dispatcher.

All those functions are automatically generated based on shiva::event.

-- Global signature
shiva.dispatcher:trigger_[event_name]_event(evt_arg);

-- Example of generated one
shiva.dispatcher:trigger_quit_game_event(evt_arg);

Parameters

Name	Description
evt_arg	type -> constructor of the current_event

Example

function on_key_pressed(evt)
    if (evt.keycode == Keyboard.Escape) then
        -- quit_game.hpp take a integer as argument for his construction
        shiva.dispatcher:trigger_quit_game_event(1)
    end
end

Entity Registry API Documentation

shiva.entity_registry:create

This function create an entity through the EnTT registry and return an unique identifier.

shiva.entity_registry:create();

Return value

Possible name	Description
entity_id	integer the entity identifier

Example

function foo()
    local entity_id = shiva.entity_registry:create()
end

shiva.entity_registry:destroy

This function destroy an entity through the EnTT registry.

shiva.entity_registry:destroy(entity_id);

Parameters

Name	Description
entity_id	integer the identifier of the entity to be destroyed.

Example

function foo()
    local id = shiva.entity_registry:create()
    shiva.entity_registry:destroy(id)
end

shiva.entity_registry:nb_entities

This function retrieve the number of entities through the EnTT registry

shiva.entity_registry:nb_entities()

Return value

Possible name	Description
nb_entities	integer the number of entities

Example

function foo()
    local id = shiva.entity_registry:create()
    assert(shiva.entity_registry:nb_entities() == 1)
    shiva.entity_registry:destroy(id)
    assert(shiva.entity_registry:nb_entities() == 0)
end

shiva.entityregistry:has_[component_name]_component

This function checks whether the requested component is associated with the given entity through the EnTT registry

All those functions are automatically generated based on the common components.

-- Global signature
shiva.entity_registry:has_[component_name]_component(entity_id);

-- Example of generated one
shiva.entity_registry:has_layer_1_component(entity_id);

Parameters

Name	Description
entity_id	integer the identifier of the entity to be verified

Return value

Possible name	Description
result	boolean true if the entity has the component false otherwise

Example

function foo()
    local entity_id = shiva.entity_registry:create()
    local component = shiva.entity_registry:add_layer_1_component(entity_id)
    local same_component = shiva.entity_registry:get_layer_1_component(entity_id)
    assert(shiva.entity_registry:has_layer_1_component(entity_id) == true, "should be true")
    shiva.entity_registry:remove_layer_1_component(entity_id)
    assert(shiva.entity_registry:has_layer_1_component(entity_id) == false, "should be false")
    return true
end