parallels.append(specpar)
par = par - stepsize
# correct near-zero imprecision of floats
if par > -1e-10 and par < 1e-10: par = 0
# avoid multiple guide instances: record all present guides:
existing_guides = list()
for guide in namedview.getElementsByTagName("sodipodi:guide"):
existing_guides.append(guide.getAttribute("id"))
n_guides = 0
# iterate over meridians list...
for lon in meridians:
# calculate position and id
guide_pos = x + (OSMTools.lon_to_x(lon,args.ZOOM) - args.X0) * width / args.NX
guide_id = "meridian{0}".format(lon)
# check if guide is already present (id in use)
if guide_id not in existing_guides:
# create Inkscape guide element, populate it and append it to the
# named view of the SVG document
guide = svg.createElement("sodipodi:guide")
guide.setAttribute("id",guide_id)
guide.setAttribute("orientation","1,0")
guide.setAttribute("position","{0},{1}".format(guide_pos,0))
namedview.appendChild(guide)
print("Added guide for meridian={0}° at x={1}.".format(lon,guide_pos))
n_guides = n_guides + 1
else:
print("Skipping already existing guide for meridian={0}°.".format(lon))
except IndexError:
print("Invalid source URL provided!")
sys.exit(1)
# check bounding box values
if args.EAST <= args.WEST or args.NORTH <= args.SOUTH:
print("Invalid bounding box values! Required: WEST < EAST and SOUTH < NORTH")
sys.exit(1)
# check zoom factor
if args.ZOOM < 0 or args.ZOOM > 18:
print("Invalid zoom factor!")
sys.exit(1)
# upper left corner of map
x0 = int(OSMTools.lon_to_x(args.WEST,args.ZOOM))
y0 = int(OSMTools.lat_to_y(args.NORTH,args.ZOOM))
# lower right corner of map
# (i.e. lower right tile next to the one which contains EAST/SOUTH -> +1)
x1 = int(OSMTools.lon_to_x(args.EAST, args.ZOOM))+1
y1 = int(OSMTools.lat_to_y(args.SOUTH,args.ZOOM))+1
tiles = [(args.ZOOM,x,y) for x in range(x0,x1) for y in range(y0,y1)]
n = len(tiles)
# calculate image dimensions based on the standard 256x256 tile
w = (x1 - x0) * 256
h = (y1 - y0) * 256
# open map image file
