Lightcone

Lightcone is a Game of Life search tool for conduits and oscillators, in the style of ptbsearch, catalyst and CatForce.

For some details on how it works, see this blog post.

Usage

To build, run git submodule update --init --recursive and then:

cmake .
./Lightcone examples/minimal.toml

Input Parameters

See examples/ for complete working inputs.

Parameter	Format	Default	Meaning
pattern	"""LifeHistory RLE"""	(required)	Initial pattern
pattern-center	[x, y]	[0, 0]	Shift applied to pattern
max-catalysts	n	100	Maximum number of catalyst
max-transparent	n	0	Maximum number of transparent catalysts
max-limited	n	1	Maximum number of 'limited' catalysts placements
first-active-range	[min, max]	[0, 100]	Allowed generation range for first interaction
active-window-range	[min, max]	[0, 500]	Allowed duration for overall reaction
min-stable-time	n	8	Required recovery duration to count as a solution
continue-after-success	true / false	true	Keep searching after finding solution?
max-stationary-time	n	0	Maximum generations a non-catalyst cell may sit still
max-stationary-count	n	0	Total population that can break the previous constraint
use-bloom-filter	true / false	false	Enable Bloom filter
print-summary	true / false	false	Print all solutions as a row-packed summary at the end

Catalysts

Add one [[catalyst]] block per catalyst type.

Parameter	Format	Default	Meaning
rle	"RLE"	(required)	Catalyst pattern
recovery-range	[min, max]	[0, 100]	Allowed interaction duration
transparent	true / false	false	Catalyst is transparent?
limited	true / false	false	Catalyst is limited for purposes of max-limited?
required	"LifeHistory RLE"	none	Cells that must remain unchanged
approach	"LifeHistory RLE"	none	Single approach signature OR
approaches	["LifeHistory RLE", ...]	none	Multiple approach signatures
forbidden	["LifeHistory RLE", ...]	none	Forbidden approach patterns at placement time

Notes:

• For non-transparent catalysts, you should provide required and at least one approach (approach or approaches).
• forbidden can be used to prevent glider eating reactions, which can bog down a search.
• Examples also include metadata keys like summary for debugging purposes; unknown keys are ignored by the parser.

Filters

Filters are checked when reporting solutions, and don't prune the search otherwise. There are two additional global parameters:

Parameter	Format	Default	Meaning
filter-mode	"ALL" / "ANY"	"ALL"	How multiple [[filter]] blocks combine
filter-match-survival-time	n	0	How long a MATCH filter must survive undisturbed to count

And each [[filter]] block has the following options:

Parameter	Format	Default	Meaning
filter	"LifeHistory RLE"	""	Target pattern / mask
filter-pos	[x, y]	[0, 0]	Translation applied to filter
filter-type	"EXACT" / "EVER" / "MATCH"	"EVER"	Filter type
filter-gen	n	-1	Single generation to check for EXACT OR
filter-range	[min, max]	[-1, -1]	Generation range to check for EXACT

Semantics for filter-type:

• EXACT: equality check during the specified generation/range
• EVER: equality check at any generation up to the filter horizon
• MATCH: match any location/symmetry during the specified generation/range.