map tile rendering base

src/c3nav/mapdata/views.py

@@ -0,0 +1,40 @@
+import subprocess
+
+from django.http import Http404, HttpResponse
+from django.shortcuts import get_object_or_404
+from shapely.geometry import box
+
+from c3nav.mapdata.models import Level, Source
+from c3nav.mapdata.render import render_svg
+
+
+def tile(request, level, zoom, x, y, format):
+    zoom = int(zoom)
+    if not (0 <= zoom <= 10):
+        raise Http404
+
+    bounds = Source.max_bounds()
+
+    x, y = int(x), int(y)
+    size = 256/2**zoom
+    minx = size * x
+    miny = size * y
+    maxx = minx + size
+    maxy = miny + size
+
+    if not box(bounds[0][1], bounds[0][0], bounds[1][1], bounds[1][0]).intersects(box(minx, miny, maxx, maxy)):
+        raise Http404
+
+    level = get_object_or_404(Level, pk=level)
+
+    svg = render_svg(level, miny, minx, maxy, maxx, scale=2**zoom)
+
+    if format == 'svg':
+        response = HttpResponse(svg, 'image/svg+xml')
+    elif format == 'png':
+        p = subprocess.run(('rsvg-convert', '--format', 'png'), input=svg.encode(), stdout=subprocess.PIPE, check=True)
+        response = HttpResponse(p.stdout, content_type="image/png")
+    else:
+        raise ValueError
+
+    return response