The background weather is now GPU-rendered: one instanced-quad draw call
over a baked sprite atlas plus a fullscreen sky shader (fog, Saharan
haze, aurora, sun rays, storm gloom and lightning flash). The old
Canvas2D renderer stays as weather-2d.js and kicks in automatically
when WebGL2 is missing; weather.js is now a thin controller that owns
the toggle, prefs and the PeteWeather API.
Effect upgrades: shared wind with gust pulses leans the whole scene
together, rain gets depth, splash pops and velocity-aligned streaks,
storms grow procedural branched lightning bolts, snow mixes soft motes
with spinning six-arm crystals, clouds drift in two parallax layers,
clear nights get a moon with maria, twinkling stars and the occasional
shooting star, blossoms and leaves tumble with a faked 3D flip.
New variants: haze (Saharan calima), wind (autumn gusts with streak
lines), hail (bouncing stones with drizzle) and aurora. The /weather
demo page switches variant, intensity and phase in place without a
reload and shows the active renderer plus an FPS meter.
Server picks variant from Lisbon-local date (rain/petals/jacaranda/motes/leaves)
and renders behind content via a canvas particle layer. Each variant has a
hand-drawn silhouette so shapes are recognizable. /weather demo route exposes
variant + intensity + phase pickers, locking the time-of-day phase override.
