I have a single polygon in a local projection system. I would like to convert that polygon into an image that can be used as an overlay on google maps. I understand that it may be better to use existing projects such as Mapnik, but I am still interested in the process of turning coordinates into pixels.
My scripts current flow is as follows:
- Convert polygons to Google Spherical Mercator Projection.
- Divide the coordinates by the map resolution (metres per pixel) for the zoom level in question.
- Transform the coordinates of the polygon to be relative to the origin of the image.
- Render the coordinates to an image file.
Will such a process result in a cartographically correct rendering of the data? Am I leaving anything out?