#
# SVG coordinate system: upper left corner, right/down
#
# guides are an Inkscape extension and follow Inkscape's coordinate system:
# lower left corner, right/up
x = float(image.getAttribute("x"))
y = float(image.getAttribute("y"))
width = float(image.getAttribute("width"))
height = float(image.getAttribute("height"))
except (IndexError,AttributeError,TypeError):
print("Could not retrieve important XML elements! Invalid Inkscape SVG file?")
sys.exit(1)
print("potential map image at x={0} y={1} w={2} h={3}".format(x,y,width,height))
lon0 = OSMTools.x_to_lon(args.X0,args.ZOOM)
lat0 = OSMTools.y_to_lat(args.Y0,args.ZOOM)
lon1 = OSMTools.x_to_lon(args.X0+args.NX,args.ZOOM)
lat1 = OSMTools.y_to_lat(args.Y0+args.NY,args.ZOOM)
#
# prepare lists of meridians and parallels
#
stepsize = 1/args.steps
special_meridians = (OSMTools.PRIME_MERIDIAN,)
special_parallels = (OSMTools.ARCTIC_CIRCLE,OSMTools.TROPIC_CANCER,OSMTools.EQUATOR,OSMTools.TROPIC_CAPRICORN,OSMTools.ANTARCTIC_CIRCLE)
# build meridians list; depends on map boundaries, stepsize and (optional) special meridians
meridians = list()
med = math.ceil(lon0*args.steps)/args.steps # round to nearest fraction inside map (round up)
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
