How to set bounding box to map?

[eruiz67]

Im trayin to represent a polygon in the map. But when I do so, The size of the polygon in the map is so little. I need a way to define a bounding box in the map, or a zoom level, so I can the the polygon bigger.

Here is the code:

import staticmaps

context = staticmaps.Context()
context.set_tile_provider(staticmaps.tile_provider_OSM)

polygon = [
    (11.946898955783189, -86.1092862482307 ),
    (11.947196373156675, -86.10915988584337 ),
    (11.947196373156675, -86.10896210123707),
    (11.946897164111272, -86.1088650402729),
    (11.946898955783189, -86.1092862482307)
]

context.add_object(
    staticmaps.Area(
        [staticmaps.create_latlng(lat, lng) for lat, lng in polygon],
        fill_color=staticmaps.parse_color("#00FF003F"),
        width=2,
        color=staticmaps.BLUE,
    )
)

# render non-anti-aliased png
image = context.render_pillow(800, 500)
image.save("polygon.pillow.png")

# render anti-aliased png (this only works if pycairo is installed)
image = context.render_cairo(800, 500)
image.write_to_png("polygon.cairo.png")

# render svg
svg_image = context.render_svg(800, 500)
with open("polygon.svg", "w", encoding="utf-8") as f:
    svg_image.write(f, pretty=True)

[lowtower]

Hello @eruiz67

the zoom should be determined automatically - in Your case it is calculated to 15.
Instead, you can set the zoom "manually" with context.set_zoom(), e.g.

...
staticmaps.context.add_object(
    staticmaps.Area(
        [staticmaps.create_latlng(lat, lng) for lat, lng in polygon],
        fill_color=staticmaps.parse_color("#00FF003F"),
        width=2,
        color=staticmaps.BLUE,
    )
)
staticmaps.context.set_zoom(17)
...

Cheers,
LT

[wyhinton]

def render_cairo(self, width: int, height: int, bounds: LatLngRect) -> typing.Any:
    """Render area using cairo

    :param width: width of static map
    :type width: int
    :param height: height of static map
    :type height: int
    :return: cairo image
    :rtype: cairo.ImageSurface
    :raises RuntimeError: raises runtime error if cairo is not available
    :raises RuntimeError: raises runtime error if map has no center and zoom
    """

    center, zoom = self.determine_center_zoom(width, height)
    if center is None or zoom is None:
        raise RuntimeError("Cannot render map without center/zoom.")

    trans = Transformer(width, height, zoom, center, self._tile_provider.tile_size())
    x, y = trans.ll2pixel(bounds.lo())
    a, b = trans.ll2pixel(bounds.hi())

    renderer = CairoRenderer(trans)
    renderer.render_background(self._background_color)
    renderer.render_tiles(self._fetch_tile)
    renderer.render_objects(self._objects)
    renderer.render_attribution(self._tile_provider.attribution())
    return crop_image_surface(renderer.image_surface(), int(x), int(b), int(a-x), int(y-b) )

staticmaps.Context.render_cairo = render_cairo

This monkey patch worked for me for the cairo renderer