islaApocalypse-v2/Tools/Scripts/Topography.cs.uid
beezm 9af5c73b04 Phase 1: port the crown-jewel noise and pass-1, and render the island
Ports MapGenerator.GenerateTopography's pass-1 loop (reference ~:553-619 at tag
pre-rewrite-reference / ab78883) into Tools/. Working code and its tuned constants
carried over verbatim, read from source rather than re-derived from a design
summary (D-050). Six elements, in the reference's execution order — the order is
load-bearing: the sinker lands before the Pow (superlinear), the Trench after it
(a raw additive wall), preTrenchFalloff captured between them.

The fractal config is now PINNED. The reference set only NoiseType/Seed/Frequency,
so the island's entire fractal character was Godot 4.7.1 constructor defaults that
nothing recorded. Measured on 4.7.2 (NoiseDefaultsProbe): Fbm / 5 / 0.5 / 2.0 / 0.0
— identical to the 4.7.1 values, so pinning reproduces the look with no delta. The
terrain no longer depends on an engine default, and the probe makes a future drift
visible instead of silent.

Two deliberate departures from the reference's literals, both flagged in-code:
  - the latitude noise offset is expressed in map widths, not the reference's raw
    +1000 px, so a resize no longer samples a different slice of the noise field
    (chat1/00 §4.2). Pinned to 1000/8192 so the 8K realization is unchanged.
  - the `if (temperature < 0.65f)` spine gate is dropped as the provable no-op it
    is — southernFade already reaches exactly 0 at 0.65. Bit-identical.

The reference's "temperature" is ported as a latitude field and deliberately NOT
named temperature: it is stage-1-local input to terrain geometry, and climate is
stage 3 (D-049 §2, D-056). The ±0.1 wobble is kept — it is what stops the spine's
southern terminus being a ruler-straight line.

Deferred to Phase 2 with the seam open: coast shelf and offshore islets (below-sea,
judged once water renders). Pass1Result exposes PreTrenchFalloff at their exact
consumption point, plus HMaxSeed for the seed-dependent curve.

Render is a direct Godot.Image, not the SubViewport capture path — that machinery
exists to composite vector overlays and is why --headless hangs; Phase 1 has none.
Hypsometric above 0.15, bathymetric below, fixed ramp anchors so seeds and ablation
rungs are comparable. No biome words anywhere.

Verified: land fraction 51.5% identical at 1024, 2048 and 10240 — the scaling
discipline holds across a 10x resize. Full-size 10240 pass: 36.3 s.

No curve, erosion, rivers, water, crater, biomes, roads, or mesher.
2026-08-19 21:27:20 -04:00

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