Allow overriding the map centre and OSM zoom level from the command
line, keeping the existing values as defaults.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Replace the heuristic choose_zoom() back-computation with a fixed
OSM_ZOOM constant (zoom 10). The orthographic projection half-extents
are now derived so that one tile pixel maps exactly to one output pixel,
eliminating bilinear interpolation artefacts on the OSM base layer.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Fetch Carto Voyager no-label base tiles and label-only tiles separately,
cached under cache/osm_tiles/{z}/ and cache/osm_tiles/labels/{z}/
- Rasterize both into the orthographic projection via exact inverse projection
(new unproject/pixel_to_geo methods on OrthoProjection)
- Render pipeline: basemap → cloud blend → label overlay (labels above clouds)
- Bilinear interpolation for base tiles; premultiplied-alpha bilinear for label
tiles to prevent dark-fringe artifacts at text edges
- Dynamic zoom selection (floor-based) from actual geographic bounding box
- Fix horizontal squish: derive HALF_W_DEG from pixel aspect ratio so
degrees-per-pixel is equal on both axes
- Add --no-basemap flag to skip tile fetching for offline/fast use
- Remove hardcoded city markers/labels when tile label overlay is present
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Render an animated clct_animation.gif alongside the per-step PNGs.
Frames are loaded and colour-quantized in parallel via rayon, then
written sequentially with the gif crate. Also converts timestamps
to CET/CEST using chrono-tz.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Downloads clat/clon concurrently via rayon::join and all forecast steps
in parallel via par_iter, then renders frames sequentially. A separate
thread pool (up to 16 threads) is used for downloads to avoid blocking
the global pool during CPU-bound rendering.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
