Polaris/code/modules/lighting

BS12 object based lighting system

Changes from tg DAL:

• Lighting is done using objects instead of subareas.

• Animated transitions. (newer tg DAL has this)

• Full colours with mixing.

• Support for lights on shuttles.

• Code:

  • Instead of one flat luminosity var, light is represented by 3 atom vars:
    • light_range; range in tiles of the light, used for calculating falloff,
    • light_power; multiplier for the brightness of lights,
    • light_color; hex string representing the RGB colour of the light.
  • setLuminousity() is now set_light() and takes the three variables above.
    • Variables can be left as null to not update them.
  • set_opacity() is now set_opacity().
  • Areas have luminosity set to 1 permanently, no hard-lighting.
  • Objects inside other objects can have lights and they properly affect the turf. (flashlights)
  • area/master and area/list/related have been eviscerated since subareas aren't needed.

Relevant vars/procs

atom: (lighting_atom.dm)

• var/light_range; range in tiles of the light, used for calculating falloff

• var/light_power; multiplier for the brightness of lights

• var/light_color; hex string representing the RGB colour of the light

• var/datum/light_source/light; light source datum for this atom, only present if light_range && light_power

• var/list/light_sources; light sources in contents that are shining through this object, including this object

• proc/set_light(l_range, l_power, l_color):

  • Sets light_range/power/color to non-null args and calls update_light()

• proc/set_opacity(new_opacity):

  • Sets opacity to new_opacity.
  • If opacity has changed, call turf.reconsider_lights() to fix light occlusion

• proc/update_light():

  • Updates the light var on this atom, deleting or creating as needed and calling .update()

turf: (lighting_turf.dm)

• var/list/affecting_lights; list of light sources that are shining onto this turf

• proc/reconsider_lights():

  • Force all light sources shining onto this turf to update

• proc/lighting_clear_overlays():

  • Delete (manual GC) all light overlays on this turf, used when changing turf to space

• proc/lighting_build_overlays():

  • Create lighting overlays for this turf

/atom/movable/lighting_overlay: (lighting_overlay.dm)

• var/lum_r, var/lum_g, var/lum_b; lumcounts of each colour

• var/needs_update; set on update_lumcount, checked by lighting process

• var/xoffset, var/yoffset; (only present when using sub-tile overlays) fractional offset of this overlay in the tile

• proc/update_lumcount(delta_r, delta_g, delta_b):

  • Change the lumcount vars and queue the overlay for update

• proc/update_overlay()

  • Called by the lighting process to update the color of the overlay