On 8 September 2010 13:42, chaoskreator <[email protected]> wrote: > Hmmm... I did as you suggested, plotting 0, -90 on my map, and it > popped up in a very strange spot.
It should have popped up vertically centred, a quarter of the way in from the left. <pause> Yes: just where you have it. This is because GLatLng needs your 750-pixel square to be divided into 360 degrees left-to-right (from -180 to +180) and 180 degrees top-to-bottom (from -90 to +90) just like the Earth. So (0,-90) is on the Equator and half-way between the Prime Meridian and the left-hand edge. To convert horizontally [longitude], divide your 750 pixels into 360 degrees and then move the origin: d = p*360/750 - 180 Vertical [latitude] conversion is a bit more difficult because your origin is at the top. d = 90 - p*180/750 Taking a point at say (300,599), those formulae give you GLatLng(-53.76,-36) It's a straightforward arithmetic relationship because of your Euclidean geometry; there's no fancy projection mathematics to deal with. -- You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en.
