TODO.txt

# Planet project

Planet improvements:
  POIs?
  Variations with each tree type (different biomes on one planet?  different planets?)
  Rivers?
  Marsh tileset not used for anything, make a swamp biome / planet?

Always show frontish/lit side when in orbit view?


# Things to integrate or get inspired by:

  https://old.reddit.com/r/proceduralgeneration/comments/nt38li/a_pixel_planet_generator_this_project_is_already/
  https://github.com/Deep-Fold/PixelPlanets

# Galaxy

renderStars takes too long - split into multiple passes too
possibly final step (sort) of realizeStars is now taking too long too

artifact around horizontal borders in layer 6

More detail in the intermediate layers:
  Add some detail paths (twirled by 80-100%?) to some of the zoom in layers
  More, stronger noise in layers 4/5 cause the visible (thresholded) details to better align with the star placements
    but, really messes up the core

Try completely different approach for layer 0
  Generate (thousands of) clusters of stars and draw them as additive glowing dots

Scale
  seed 1 = sum = 1.9M
  @ 100B stars, that's 52.6K per density value = 13.4M for a single core pixel
  @ 1B = 134K
  @ 100B, 512res = 3.3M
  @ 100B, 1024res = 838K

  How many layers of zoom to get ~50 stars on-screen at 100% density?
    if linear, @100B, and dividing by 4 each time, 15 zoom levels  (4^15 = 1B)
      that's looking at 3LY across, that's good
      zoom is 2^15 = 32K which means even a 1K texel gets subdivided into 32*32 screens at max zoom

  Milky Way is 105Kly in diameter
  1 LY = 63K au
  Pluto = 1/1000 ly away from the sun (63au)

  Elite Dangerous:
    galactic core: 3LY (parsec) cubed holds 10 million stars
    the bubble: 3-5 LY betweens closest stars? => 1 star per parsec!
    the fringe often 50LY between stars, more than 100LY in dark areas
  So, what if our density value is instead a "distance between stars"

Plan:
  galaxy top level is 128Kly across
  layer is a 256 density map plus points of interest
  new density map always a 4x reduction?
  output is a texture and a density map and we just blend them

Galaxy Layers
  0: Galaxy

  6: Stars as points, 3x3 blurred
  7: Stars rendered as gaussian
  8: Stars rendered as minisprites

Planet layers
  zoom layers
    0 = orrery
    1 = globe
    2 = unlit world map, scrollable, looping, zoomable
  zoom sublayers
    0 = full
    3 = max texture size = pixel art
    7 = max zoom