Vertical 'Height above clutter' slider on the left of the map now
matches cnHeat's experience: pick an SM install height, the heatmap
re-renders to show only the coverage achievable from that height.
Backend
- New JSONB height_tiers column on coverages keyed by string metres
→ relative PNG path.
- CoverageWorker runs compute_pixels once per tier in
[1.83, 3.05, 4.57, 6.10, 9.14, 12.19] m (~6/10/15/20/30/40 ft)
by varying receiver_height_m on a copied struct. Each tier
writes its own raster + PNG via Raster.write/4 with a per-height
filename suffix; the default 3.05 m tier also populates the
legacy raster_path / png_path so existing show pages keep
working.
Frontend
- Vertical range slider (writing-mode: vertical-lr) anchored
centre-left. Step picks one of HEIGHT_TIERS_FT; label updates
to '6 ft'..'40 ft'.
- pngForCoverage/2 picks the closest available tier from the
payload's height_tiers map, falling back to the original png
for coverages not yet recomputed.
- On slider change the JS swaps each L.imageOverlay's URL via
setUrl, drops the cached pixel data, and re-decodes so the RSSI
filter still applies. coverage_hooks chunk: 20 KB → 22 KB.
Graham McIntire
434f5782d0