CatForce

GoL Catalyst search utility based on LifeAPI library.

Usage

Run make, and then ./CatForce inputfile.in. Currently only tested with clang.

Input File Format

See examples/p83.in etc. Some useful lists of catalysts are given in catlists/.

Parameters are separated by " " - i.e. space. Parameters in parentheses are optional.

Line	Parameter	Description
max-gen	n	Overall maximum generation
start-gen	n	The min gen the first encounter occurs
last-gen	n	The max gen the first encounter occurs
num-catalyst	n	The number of catalyst to place
num-transparent	n	The number of catalysts marked transparent that may appear
stable-interval	n	Gens the catalysts must remain untouched to be considered stable
search-area	x y w h	Search area
pat	rle	The active pattern
	(dx dy)	Offset applied to the active pattern
cat	rle	A catalyst
	max-active	Number of generations in a row the catalyst may be missing
	dx dy	Offset applied centre the catalyst, typically negative
	symmetry-char	Character denoting the symmetry of the catalyst (see below)
	(forbidden rle x y)	Forbidden pattern around the catalyst (see below)
	(required rle x y)	Cells of a catalyst that must stay ON in every generation
	(antirequired rle x y)	Cells of a catalyst that must stay OFF in every generation
	(locus rle x y)	Cells of a catalyst that must interact first
	(must-include)	Solutions must use at least one mustinclude catalyst
	(transparent)	Marked as transparent for the purposes of num-transparent
	(check-recovery)	Always check the catalyst is recovered after exactly max-active gens
	(sacrificial)	Does not need to recover
output	filename	Output filename
(and/or)filter	genOrRange rle dx dy	Filter that must be matched for the solution to be accepted (see below)
match	genOrRange rle	Filter that checks whether the pattern occurs anywhere
max-junk	n	For filters, the maximum non-matching non-catalyst population
full-report	filename	Output filename for solutions ignoring all pattern filters
max-category-size	n	Maximum output row length before more solutions are dropped
fit-in-width-height	w h	Only allow solutions where all catalysts fit in a w by h rectangle
also-required	rle x y	Require rle to be present in every generation
symmetry	symmetry-code	Global symmetry of the entire pattern (see below)

Catalyst Symmetry: A character specifying what transformations are applied to the catalyst:

• |: reflect across y, for D4x catalysts (e.g. ship)
• -: reflect across x
• /: reflect diagonally, for D4+ catalysts (e.g. table on table)
• \: reflect diagonally the other way
• x: reflect diagonally both ways, for C2 symmetrical catalysts (e.g. snake)
• + or @: rotate all 90 degree increments, for D2- or D2/ catalysts (e.g. boat)
• *: all transforms, for C1 catalysts

Filters: Every potential solution will be checked against the provided filters: only solutions that match the filters will be kept. There are two variants: andfilter and orfilter. Every andfilter ... must match and at least one orfilter ... must match for the solution to succeed. A match filter pattern-matches the solution for the specified pattern, and succeeds if the pattern occurs anywhere (and otherwise behaves like an andfilter).

Filters that use a range of generations will only succeed after every catalyst has interacted.

Forbidden: Checks for rle in the same location as the catalyst. If rle is matched in any generation, the solution is dropped. You can see forbidden as a "catalyst attached filter", i.e. the filter location is based on the catalyst location. Intended to exclude eaters/boat-bits and similar unwanted garbage. You may have several forbidden patterns per catalyst. See the files in catlists for examples.

Check Recovery: Catalysts with the check-recovery attribute are immediately tested for whether they recover in max-active generations, without the support of any further catalysts. This is useful for catalysts with a bait still life that has a long recovery time, like the hive-pushes or the loaf-spin catalysts.

Symmetric Searches

symmetry s automatically applies the symmetry s to the active pattern and catalysts. The options for s are:

• D2 symmetries: D2| (reflect across x = 0), D2|even (x=-0.5), D2- (y=0), D2-even (y=-0.5), D2\ (y=x) and D2/ (y=-x)
• C2 symmetries: C2_1 (bounding box odd by odd), C2_2 (odd by even), C2_4 (even by even)
• C4 symmetries: C4_1, (odd by odd) C4_4 (even by even)
• D4 symmetries: D4_+1, D4_+2 (odd by even),D4_+4, D4_x1, and D4_x4
• D8 symmetries: D8_1 and D8_4

The options D2 follow LLS, while the rest of the symmetries follow Catagolue. LifeWiki has a more in-depth explanation, though the notation there is slightly different. (They choose C2_2 to be even by odd not odd by even).

There are LLS-inspired alternatives for the other groups:

• D2 symmetries: as above
• C2 symmetries: C2 C2even C2|even C2-even
• C4 symmetries: C4 C4even
• D4 symmetries: D4+ D4+|even D4+-even D4+|even D4x D4xeven
• D8 symmetries: D8 D8even

The default is "odd" transformations, i.e. those that fix the cell at (0,0); verticaleven and horizontaleven (referring to bounding box dimensions) are recognized as equivalent to -even and |even, respectively.