/datum/beam

Beam Datum and Effect
IF YOU ARE LAZY AND DO NOT WANT TO READ, GO TO THE BOTTOM OF THE FILE AND USE THAT PROC!
This is the beam datum! It's a really neat effect for the game in drawing a line from one atom to another.
It has two parts:
The datum itself which manages redrawing the beam to constantly keep it pointing from the origin to the target.
The effect which is what the beams are made out of. They're placed in a line from the origin to target, rotated towards the target and snipped off at the end.
These effects are kept in a list and constantly created and destroyed (hence the proc names draw and reset, reset destroying all effects and draw creating more.)
You can add more special effects to the beam itself by changing what the drawn beam effects do. For example you can make a vine that pricks people by making the beam_type
include a crossed proc that damages the crosser. Examples in venus_human_trap.dm

Vars
beam_color	The color of the beam we're drawing.
beam_type	the objects placed in the elements list
elements	list of beam objects. These have their visuals set by the visuals var which is created on starting
emissive	If we use an emissive appearance
icon	icon used by the beam.
icon_state	icon state of the main segments of the beam
max_distance	The beam will qdel if it's longer than this many tiles.
origin	where the beam goes from
override_origin_pixel_x	If set will be used instead of origin's pixel_x in offset calculations
override_origin_pixel_y	If set will be used instead of origin's pixel_y in offset calculations
override_target_pixel_x	If set will be used instead of targets's pixel_x in offset calculations
override_target_pixel_y	If set will be used instead of targets's pixel_y in offset calculations
target	where the beam goes to
visuals	This is used as the visual_contents of beams, so you can apply one effect to this and the whole beam will look like that. never gets deleted on redrawing.
Procs
Draw	Creates the beam effects and places them in a line from the origin to the target. Sets their rotation to make the beams face the target, too.
Start	Proc called by the atom Beam() proc. Sets up signals, and draws the beam for the first time.
redrawing	Triggered by signals set up when the beam is set up. If it's still sane to create a beam, it removes the old beam, creates a new one. Otherwise it kills the beam.

Var Details

var
beam_color
–

The color of the beam we're drawing.

var
beam_type
–

the objects placed in the elements list

var
elements
– /list

list of beam objects. These have their visuals set by the visuals var which is created on starting

var
emissive
–

If we use an emissive appearance

var
icon
–

icon used by the beam.

var
icon_state
–

icon state of the main segments of the beam

var
max_distance
–

The beam will qdel if it's longer than this many tiles.

var
origin
– /atom

where the beam goes from

var
override_origin_pixel_x
–

If set will be used instead of origin's pixel_x in offset calculations

var
override_origin_pixel_y
–

If set will be used instead of origin's pixel_y in offset calculations

var
override_target_pixel_x
–

If set will be used instead of targets's pixel_x in offset calculations

var
override_target_pixel_y
–

If set will be used instead of targets's pixel_y in offset calculations

var
target
– /atom

where the beam goes to

var
visuals
– /obj/effect/ebeam

This is used as the visual_contents of beams, so you can apply one effect to this and the whole beam will look like that. never gets deleted on redrawing.

Proc Details

proc
Draw
()

Creates the beam effects and places them in a line from the origin to the target. Sets their rotation to make the beams face the target, too.

proc
Start
()

Proc called by the atom Beam() proc. Sets up signals, and draws the beam for the first time.

proc
redrawing
(/atom/movable/mover, /atom/oldloc, direction)

Triggered by signals set up when the beam is set up. If it's still sane to create a beam, it removes the old beam, creates a new one. Otherwise it kills the beam.

Arguments: mover: either the origin of the beam or the target of the beam that moved. oldloc: from where mover moved. direction: in what direction mover moved from.

/datum/beam

Vars

Procs

Var Details

var beam_color –

var beam_type –

var elements – /list

var emissive –

var icon –

var icon_state –

var max_distance –

var origin – /atom

var override_origin_pixel_x –

var override_origin_pixel_y –

var override_target_pixel_x –

var override_target_pixel_y –

var target – /atom

var visuals – /obj/effect/ebeam