Magical gene / lines and strokes

Internal Flow

Thin contour lines in nested groups, tracking the muscles underneath - the back of the shoulder, the sweep of the ribcage, the front of the hindquarter - and carrying on over the face and the legs.

What it can come out as

Outcome	Carrying
Internal Flow	`Ifl/Ifl` · `Ifl/Ifc` · `Ifl/n`
Coloured Internal Flow	`Ifc/Ifc`
Wild type	`Ifc/n` · `n/n`

How each one is actually drawn - region by region, and the layers it is built from - is on the coding tab.

Crossing two of them

Finding one

About 1 in 1,786 wild horses is born showing this. That is the whole of the supply: catch one, or make one with the carrot below. Breeds set their own pools and a breed built around this gene will carry it far more often than the wild population does.

Wild pair	Shows as	How often
`Ifl/Ifl`	Internal Flow	0.002% — 1 in 50,000
`Ifl/Ifc`	Internal Flow	0.008% — 1 in 12,500
`Ifl/n`	Internal Flow	0.038% — 1 in 2,632
`Ifc/Ifc`	Coloured Internal Flow	0.008% — 1 in 12,500
`n/n`	Wild type	99.944%

Its gene carrot

The file

common/src/main/resources/horsegenetics/genes/internal_flow.json — a data-driven gene, not a Java class. It is listed in the index.json beside it and registered by Genes' class initialiser at startup.

Key	`horsegenetics.internal_flow`
Phase	magical — it adds signed colour in phase 3, after the pigment has resolved
Priority	362 — where it sits in the one `(priority, key)` paint order
Alleles	`Ifl` · `Ifc` · `n`
Varies per horse	4 values drawn once off the expressing allele copy, so a foal that inherits the copy inherits the look
Built from	NOISE, SPECKLE, STROKES, TOWARD

What it paints

Each outcome, described the way the gene file describes it, and then the layers that draw it in the order they are painted. The prose is the part a reader checks a bake against; the list underneath is what the engine actually did.

Internal Flow

Lines of even width - no spindle, no taper along the run - laid in nested families of two to five that share a curve. Two to four families a side over the barrel and neck, and the same contouring carrying on over the face and down the legs, where the families are shorter and fewer. Rather more than half of each line is continuous and the rest breaks into two or three dashes with tapered ends, which is what keeps the marking from reading as drawn on.

nested contour families along the body — STROKES × NOISE, painted with TOWARD
the dashes some of the lines break into — STROKES × SPECKLE, painted with TOWARD

Coloured Internal Flow

The same marking in a colour the line carries rather than in white. Fully recessive: it takes two copies, and a single copy beside the white allele shows white. It never gives blue eyes, whatever the white form does.

nested contour families along the body, in colour — STROKES × NOISE, painted with TOWARD
the dashes some of the lines break into, in colour — STROKES × SPECKLE, painted with TOWARD

Wild type

No contour lines.

Paints nothing.