Two fixes from user feedback on the hydrology view:
1. Rivers looked too sparse. Investigated coupling rainfall into discharge
(climate precip -> river rainfall): it does NOT work as hoped because river
*location* is set by drainage topology (where water collects), not local
rainfall -- weighting rainfall mostly changes river *size*, and concentrating
a fixed water budget pushes mid-size rivers below the display threshold, so
FEWER rivers show. Reverted that approach. Instead lower the default
riverThreshold 50 -> 25 so tributaries render too: a richer, more visible
network (~2x river cells on test worlds) without descending into noise.
Tunable in planet.cfg.
2. Clicking a tile overlaid a low-res, always-elevation-coloured subgrid patch
on the 3D globe that clashed with the active colour mode and read as a
"strange pattern". Removed the globe overlay; the clicked tile's high-res
subgrid still shows in the right-side detail panel.
test_logic + test_biota pass; full app builds clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Drift-time peaks used to rail into the hard elevation clamp and flatten into a
9000 m plateau (the clamp lived in step(), erode() AND hydrology(), so erosion
re-flattened them every tick). Replace the hard ceiling with a probabilistic
soft cap: above peakSoftCapStart (7000 m) the chance a tick's uplift "takes"
falls linearly to 0 at peakSoftCapEnd (12000 m); a lost grow roll forfeits the
uplift and shaves a random 0..peakFailDrop (200 m) off. Peaks now spread smoothly
across a height band (strong orogeny reaches ~10-11 km, most cluster lower) with
zero cells pinned at the ceiling.
- The roll is a pure hash of (cellIndex, erodeIter, seed): never touches
rngState, bit-identical across OpenMP thread counts, and since erodeIter is
saved (step/erode run 1:1 in drift) F5/F9 resumes bit-identical -- no save bump.
- Drift-only (gated on Planet::drifting) so Phase-1 forming still auto-settles.
- The hard clamp's upper bound now tracks peakSoftCapEnd in all three places
(step/erode/hydrology); lower -11000 m unchanged.
- New planet.cfg knobs peakSoftCapStart / peakSoftCapEnd / peakFailDrop with
validation (+ start < end cross-rule). Docs updated (CLAUDE.md, BUILD.md).
Verified headless: smooth 8.5->10.5 km taper, 0 pinned, determinism + exact
resume intact, test_logic + test_biota pass, full app builds clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
World-Creation stage after biomes. Two layers (raylib-free engine):
- Per-cell density scalars (flora/fauna/funga in [0,1]) derived from the
climate fields each tick (drive color modes 8/9/0). Flora = Liebig-min of
temp & moisture; fauna ~ flora with carnivores gated on local prey; funga =
moisture/organic-matter-led + cold-tolerant. Zero on water/ice.
- On-demand discrete population (key L, saved as v7): each land cell draws
broad archetypes from a comprehensive table into a per-kind slot cap +
density-scaled point budget (size -> cost), weighted by biome/climate
suitability and a regional bonus for same-biome neighbours. Separate RNG
seeded from cfg.seed so generating biota never perturbs tectonic determinism.
Organisms are labelled by taxonomy (Family + Size + role, e.g. "Felidae
(Big, Carnivore)") with the full Class > Order > Family tree stored, never an
informal common name. Cell-info panel word-wraps + aggregates duplicates so the
lists no longer get cut off.
New: src/sim/PlanetBiota.{hpp,cpp} + PlanetFlora/Fauna/FungiGen.cpp, color
modes/colors, bio* config knobs, save v7 (older saves load with empty
population), test_biota.cpp (densities, fauna<=capacity, carnivore gating,
slot/point budgets, determinism + RNG isolation, v7 round-trip). Docs updated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
C++/raylib semi-realistic fantasy/sci-fi planet generator on a fixed icosphere
grid (Eulerian: properties flow over fixed cells). World-creation stages:
tectonics, continental drift & erosion, hydrology (rivers/lakes), climate
(temperature + orographic precipitation), and biome classification. Engine in
src/sim (raylib-free, headless-testable), viewer in src/render. See CLAUDE.md
and docs/ (design-notes.md, fauna-flora-plan.md = next step).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
