Dynamically derive thumbnails

.gitignore

@@ -1,3 +1,4 @@
 data/plats.geojson
 data/track.geojson
 satellite/
+images/thumbs/*

Makefile

@@ -1,7 +1,17 @@
+THUMB_SRC := $(wildcard images/*.jpg)
+THUMB_FILES := $(patsubst images/%.jpg, images/thumbs/%.jpg, $(THUMB_SRC))
+
 .PHONY: deploy
-deploy: data/plats.json data/track.geojson satellite
+deploy: data/plats.json data/track.geojson satellite $(THUMB_FILES)
 	rsync -avz --exclude=unused/ --delete ./ bert:/srv/www/lawrencedeerclub.chandlerswift.com/
 
+# Build a thumbnail next to each source image so new photos are picked up automatically.
+images/thumbs/%.jpg: images/%.jpg | images/thumbs
+	magick $< -resize 400x400 -quality 80 $@
+
+images/thumbs:
+	mkdir -p $@
+
 data/plats.json: scripts/get_plats.py
 	./scripts/get_plats.py data/plats.geojson