overlay_lighting

Movable atom overlay-based lighting component.

Component works by applying a visual object to the parent target.
The component tracks the parent's loc to determine the current_holder.
The current_holder is either the parent or its loc, whichever is on a turf. If none, then the current_holder is null and the light is not visible.
Lighting works at its base by applying a dark overlay and "cutting" said darkness with light, adding (possibly colored) transparency.
This component uses the visible_mask visual object to apply said light mask on the darkness.
The main limitation of this system is that it uses a limited number of pre-baked geometrical shapes, but for most uses it does the job.
Another limitation is for big lights: you only see the light if you see the object emiting it.
For small objects this is good (you can't see them behind a wall), but for big ones this quickly becomes prety clumsy.

Vars
light	Datum that actually creates the overlay we manage
lum_power	How much this light affects the dynamic_lumcount of turfs.
lumcount_range	Ceiling of range, integer without decimal entries.
luminosity_turf	The turf we are currently displaying light on, if any
Procs
add_dynamic_lumi	Adds the luminosity and source for the affected movable atoms to keep track of their visibility.
clean_old_cells	Clears ourselves from spatial grid's dynlights lists
on_holder_moved	Called when current_holder changes loc.
on_light_eater	Handles putting the source for overlay lights into the light eater queue since we aren't tracked by /atom/var/light_sources
on_light_flags_change	Triggered right after the parent light flags change.
on_toggle	Toggles the light on and off.
register_new_cells	Populates the affected_turfs lazylist, adding to its contents the effects of being near the light.
remove_dynamic_lumi	Removes the luminosity and source for the affected movable atoms to keep track of their visibility.
set_color	Changes the light's color, pretty straightforward.
set_light_render_source	Changes the light's color, pretty straightforward.
set_power	Changes the intensity/brightness of the light by altering the visual object's alpha.
set_range	Changes the range which the light reaches. 0 means no light, 6 is the maximum value.
turn_off	Toggles the light off.
turn_on	Toggles the light on.
update_luminosity_cells	Clears the old affected cells and populates the new ones.

Var Details

var
light
– /datum/light_overlay

Datum that actually creates the overlay we manage

var
lum_power

How much this light affects the dynamic_lumcount of turfs.

var
lumcount_range

Ceiling of range, integer without decimal entries.

var
luminosity_turf
– /turf

The turf we are currently displaying light on, if any

Proc Details

proc
add_dynamic_lumi
(/atom/movable/relevant_holder)

Adds the luminosity and source for the affected movable atoms to keep track of their visibility.

proc
clean_old_cells
()

Clears ourselves from spatial grid's dynlights lists

proc
on_holder_moved
(/atom/movable/source, /atom/old_loc, dir, forced)

Called when current_holder changes loc.

proc
on_light_eater
(/datum/source, /list/light_queue, /datum/light_eater)

Handles putting the source for overlay lights into the light eater queue since we aren't tracked by /atom/var/light_sources

proc
on_light_flags_change
(/atom/source, old_flags)

Triggered right after the parent light flags change.

proc
on_toggle
(/atom/source, old_value)

Toggles the light on and off.

proc
register_new_cells
()

Populates the affected_turfs lazylist, adding to its contents the effects of being near the light.

proc
remove_dynamic_lumi
(/atom/movable/relevant_holder)

Removes the luminosity and source for the affected movable atoms to keep track of their visibility.

proc
set_color
(/atom/source, old_color)

Changes the light's color, pretty straightforward.

proc
set_light_render_source
(/atom/source, old_render_source)

Changes the light's color, pretty straightforward.

proc
set_power
(/atom/source, old_power)

Changes the intensity/brightness of the light by altering the visual object's alpha.

proc
set_range
(/atom/source, old_range)

Changes the range which the light reaches. 0 means no light, 6 is the maximum value.

proc
turn_off
()

Toggles the light off.

proc
turn_on
()

Toggles the light on.

proc
update_luminosity_cells
()

Clears the old affected cells and populates the new ones.

overlay_lighting /datum/component/overlay_lighting

Vars

Procs

Var Details

var light – /datum/light_overlay

var lum_power

var lumcount_range

var luminosity_turf – /turf

Proc Details

proc add_dynamic_lumi(/atom/movable/relevant_holder)

proc clean_old_cells()

proc on_holder_moved(/atom/movable/source, /atom/old_loc, dir, forced)

proc on_light_eater(/datum/source, /list/light_queue, /datum/light_eater)

proc on_light_flags_change(/atom/source, old_flags)

proc on_toggle(/atom/source, old_value)

proc register_new_cells()

proc remove_dynamic_lumi(/atom/movable/relevant_holder)

proc set_color(/atom/source, old_color)

proc set_light_render_source(/atom/source, old_render_source)

proc set_power(/atom/source, old_power)

proc set_range(/atom/source, old_range)

proc turn_off()

proc turn_on()

proc update_luminosity_cells()