DayNight.SunShadow returns a cell offset opposite the sun's east-west position, longest near sunrise/sunset (low sun) and zero at noon/night, tilted slightly south so shadows fall in front of occluders. LightmapBuilder gains a directional shadow pass (MaxShadowCells length cap, SunShadowStrength darkening); LightmapSystem feeds it the current sun shadow each rebuild. Tests cover SunShadow's day-arc behaviour and the builder's directional darkening.
Extend the Lighting module with a per-cell lightmap. LightmapBuilder (pure,
tested) fills an ambient base, shades occluder cells, and adds point lights
that attenuate with distance and are blocked by occluders between source and
cell (grid-traced soft shadows). Lightmap holds the grid plus a greyscale
texture (Upload) and a bilinear SampleAt for the simulation; a PointLight
component places lights in the world. LightmapSystem rebuilds the grid a few
times a second (ambient from the day/night cycle with a night floor, occluders
from a game-supplied grid, point lights from the ECS); LightmapRenderSystem
multiplies the lightmap over the world after the sprite flush and under the
HUD. Wired via scene.UseLighting(...), sampled through Lighting.SampleAt. Docs
updated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>