preview images for routes

src/c3nav/mapdata/urls.py

@@ -15,7 +15,7 @@ register_converter(ArchiveFileExtConverter, 'archive_fileext')
 urlpatterns = [
     path('<int:level>/<sint:zoom>/<sint:x>/<sint:y>.png', tile, name='mapdata.tile'),
     path('preview/l/<loc:slug>.png', preview_location, name='mapdata.preview.location'),
-    # path('preview/r/<loc:slug>/<loc:slug2>.png', preview_route, name='mapdata.preview.route'),
+    path('preview/r/<loc:slug>/<loc:slug2>.png', preview_route, name='mapdata.preview.route'),
     path('<int:level>/<sint:zoom>/<sint:x>/<sint:y>/<a_perms:access_permissions>.png', tile, name='mapdata.tile'),
     path('history/<int:level>/<h_mode:mode>.<h_fileext:filetype>', map_history, name='mapdata.map_history'),
     path('cache/package.<archive_fileext:filetype>', get_cache_package, name='mapdata.cache_package'),

src/c3nav/mapdata/views.py

@@ -12,7 +12,7 @@ from django.shortcuts import get_object_or_404
 from django.utils.http import content_disposition_header
 from django.views.decorators.cache import cache_page
 from django.views.decorators.http import etag
-from shapely import Point, box
+from shapely import Point, box, LineString, unary_union
 
 from c3nav.mapdata.middleware import no_language
 from c3nav.mapdata.models import Level, MapUpdate
@@ -24,7 +24,6 @@ from c3nav.mapdata.utils.cache import CachePackage, MapHistory
 from c3nav.mapdata.utils.tiles import (build_access_cache_key, build_base_cache_key, build_tile_access_cookie,
                                        build_tile_etag, get_tile_bounds, parse_tile_access_cookie)
 
-
 PREVIEW_HIGHLIGHT_FILL_COLOR = settings.PRIMARY_COLOR
 PREVIEW_HIGHLIGHT_FILL_OPACITY = 0.1
 PREVIEW_HIGHLIGHT_STROKE_COLOR = PREVIEW_HIGHLIGHT_FILL_COLOR
@@ -60,35 +59,7 @@ def enforce_tile_secret_auth(request):
         raise PermissionDenied
 
 
-@no_language()
+def bounds_for_preview(geometry, cache_package):
-@cache_page(60 * 5)
-def preview_location(request, slug):
-    from c3nav.site.views import check_location
-    from c3nav.mapdata.utils.locations import CustomLocation
-    from c3nav.mapdata.models.geometry.base import GeometryMixin
-
-    location = check_location(slug, request)
-    highlight = True
-    if location is None:
-        raise Http404
-    if isinstance(location, CustomLocation):
-        geometry = Point(location.x, location.y)
-        level = location.level.pk
-    elif isinstance(location, GeometryMixin):
-        geometry = location.geometry
-        level = location.level_id
-    elif isinstance(location, Level):
-        [minx, miny, maxx, maxy] = location.bounds
-        geometry = box(minx, miny, maxx, maxy)
-        level = location.pk
-        highlight = False
-    else:
-        raise NotImplementedError(f'location type {type(location)} is not supported yet')
-    cache_package = CachePackage.open_cached()
-
-    if isinstance(geometry, Point):
-        geometry = geometry.buffer(1)
-
     bounds = geometry.bounds
 
     if not cache_package.bounds_valid(bounds[0], bounds[1], bounds[2], bounds[3]):
@@ -111,9 +82,43 @@ def preview_location(request, slug):
     maxx = int(bounds[2] + dx / 2)
     miny = int(bounds[1] - dy / 2)
     maxy = int(bounds[3] + dy / 2)
-
     img_scale = PREVIEW_IMG_HEIGHT / height
 
+    return minx, miny, maxx, maxy, img_scale
+
+
+@no_language()
+@cache_page(60 * 5)
+def preview_location(request, slug):
+    from c3nav.site.views import check_location
+    from c3nav.mapdata.utils.locations import CustomLocation
+    from c3nav.mapdata.models.geometry.base import GeometryMixin
+
+    location = check_location(slug, None)
+    highlight = True
+    if location is None:
+        raise Http404
+    if isinstance(location, CustomLocation):
+        geometry = Point(location.x, location.y)
+        level = location.level.pk
+    elif isinstance(location, GeometryMixin):
+        geometry = location.geometry
+        level = location.level_id
+    elif isinstance(location, Level):
+        [minx, miny, maxx, maxy] = location.bounds
+        geometry = box(minx, miny, maxx, maxy)
+        level = location.pk
+        highlight = False
+    else:
+        raise NotImplementedError(f'location type {type(location)} is not supported yet')
+
+    cache_package = CachePackage.open_cached()
+
+    if isinstance(geometry, Point):
+        geometry = geometry.buffer(1)
+
+    minx, miny, maxx, maxy, img_scale = bounds_for_preview(geometry, cache_package)
+
     level_data = cache_package.levels.get(level)
     if level_data is None:
         raise Http404
@@ -125,13 +130,116 @@ def preview_location(request, slug):
                            category='highlight')
     data = image.render()
     response = HttpResponse(data, 'image/png')
-    # TODO use cache key like in tile render function
+    # TODO use cache key like in tile render function, same for the routing option
     return response
 
 
 @no_language()
+@cache_page(60 * 5)
 def preview_route(request, slug, slug2):
-    raise NotImplementedError()
+    from c3nav.routing.router import Router
+    from c3nav.routing.models import RouteOptions
+    from c3nav.routing.exceptions import NotYetRoutable
+    from c3nav.routing.exceptions import LocationUnreachable
+    from c3nav.routing.exceptions import NoRouteFound
+    from c3nav.site.views import check_location
+    from c3nav.mapdata.utils.locations import CustomLocation
+    from c3nav.mapdata.utils.geometry import unwrap_geom
+    origin = check_location(slug, None)
+    destination = check_location(slug2, None)
+    try:
+        route = Router.load().get_route(origin=origin,
+                                        destination=destination,
+                                        permissions=set(),
+                                        options=RouteOptions())
+    except NotYetRoutable:
+        raise Http404()
+    except LocationUnreachable:
+        raise Http404()
+    except NoRouteFound:
+        raise Http404()
+
+    route_items = [route.router.nodes[x] for x in route.path_nodes]
+    route_points = [(item.point.x, item.point.y, route.router.spaces[item.space].level_id) for item in route_items]
+
+    from c3nav.mapdata.models.geometry.base import GeometryMixin
+    if isinstance(origin, CustomLocation):
+        origin_level = origin.level.pk
+        origin_geometry = Point(origin.x, origin.y)
+    elif isinstance(origin, GeometryMixin):
+        origin_level = origin.level_id
+        origin_geometry = origin.geometry
+    elif isinstance(origin, Level):
+        raise Http404  # preview for routes from a level don't really make sense
+    else:
+        raise NotImplementedError(f'location type {type(origin)} is not implemented')
+
+    if isinstance(origin_geometry, Point):
+        origin_geometry = origin_geometry.buffer(1)
+
+    if isinstance(destination, CustomLocation):
+        destination_level = destination.level.pk
+        destination_geometry = Point(destination.x, destination.y)
+    elif isinstance(destination, GeometryMixin):
+        destination_level = destination.level_id
+        destination_geometry = destination.geometry
+    elif isinstance(destination, Level):
+        destination_level = destination.pk
+        destination_geometry = None
+    else:
+        destination_level = origin_level  # just so that it's set to something
+        destination_geometry = None
+    if destination_level != origin_level:
+        destination_geometry = None
+
+    if isinstance(destination_geometry, Point):
+        origin_geometry = destination_geometry.buffer(1)
+
+    lines = []
+    line = None
+    for x, y, level in route_points:
+        if line is None and level == origin_level:
+            line = [(x, y)]
+        elif line is not None and level == origin_level:
+            line.append((x, y))
+        elif line is not None and level != origin_level:
+            if len(line) > 1:
+                lines.append(line)
+            line = None
+    if line is not None and len(line) > 1:
+        lines.append(line)
+
+    route_geometries = [LineString(line) for line in lines]
+
+    all_geoms = [*route_geometries, unwrap_geom(origin_geometry), unwrap_geom(destination_geometry)]
+    combined_geometry = unary_union([x for x in all_geoms if x is not None])
+
+    cache_package = CachePackage.open_cached()
+
+    minx, miny, maxx, maxy, img_scale = bounds_for_preview(combined_geometry, cache_package)
+
+    level_data = cache_package.levels.get(origin_level)
+    if level_data is None:
+        raise Http404
+    renderer = MapRenderer(origin_level, minx, miny, maxx, maxy, scale=img_scale, access_permissions=set())
+    image = renderer.render(ImageRenderEngine)
+
+    if origin_geometry is not None:
+        image.add_geometry(origin_geometry, stroke=StrokeAttribs(PREVIEW_HIGHLIGHT_STROKE_COLOR,
+                                                                 PREVIEW_HIGHLIGHT_STROKE_WIDTH),
+                           category='highlight')
+    if destination_geometry is not None:
+        image.add_geometry(destination_geometry, stroke=StrokeAttribs(PREVIEW_HIGHLIGHT_STROKE_COLOR,
+                                                                      PREVIEW_HIGHLIGHT_STROKE_WIDTH),
+                           category='highlight')
+
+    for geom in route_geometries:
+        image.add_geometry(geom, stroke=StrokeAttribs(PREVIEW_HIGHLIGHT_STROKE_COLOR, PREVIEW_HIGHLIGHT_STROKE_WIDTH),
+                           category='route')
+    data = image.render()
+    response = HttpResponse(data, 'image/png')
+    # TODO use cache key like in tile render function
+    return response
 
 
 @no_language()

src/c3nav/site/views.py

@@ -135,11 +135,10 @@ def map_index(request, mode=None, slug=None, slug2=None, details=None, options=N
     if origin is not None and destination is not None:
         metadata = {
             'title': _('Route from %s to %s') % (origin.title, destination.title),
-            # TODO: enable when route image generation is implemented
+            'preview_img_url': request.build_absolute_uri(reverse('mapdata.preview.route', kwargs={
-            # 'preview_img_url': request.build_absolute_uri(reverse('mapdata.preview.route', kwargs={
+                'slug': slug,
-            #     'slug': slug,
+                'slug2': slug2,
-            #     'slug2': slug2,
+            })),
-            # })),
             'canonical_url': request.build_absolute_uri(reverse('site.index', kwargs={
                 'mode': 'r',
                 'slug': slug,