Baxslash Pinch Zoom with Google Maps

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Wilf

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Joined: 1st Jun 2006

Location: Gone to Unity.

Posted: 13th May 2013 01:44

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I have been playing around with the Google Maps API and realized I could pull down map images with AGKs HTTP commands.

So I mixed that with Baxslashes awesome Pinch and Zoom tutorial and made an app that displays a map - see attached.

My question:

Looking over the Google Maps documention, I see its possible to derive a pixel coordinate from a world coordinate. That would be useful to display markers, icons etc at real locations. However I'm clearly missing a core concept because my attempts at the conversion

+ Code Snippet

pixelCoordinate = worldCoordinate * 2zoomLevel

using

+ Code Snippet

function Pow( base as float, exp as float )
    result# = base ^ exp
endfunction result#

results in nonsense numbers.

Does anyone know how to convert them?

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baxslash

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Posted: 13th May 2013 09:56

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This is really cool. Nice work!

I think of the co-ordinates would change as the user zoomed it would work even better as currently the only way to navigate around is by entering co-ordinates in the boxes. A little more work and you have a handy little bit of code there.

I haven't time to check your other problem but if I get a chance I'll look into it.

this.mess = abs(sin(times#))

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Wilf

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Posted: 13th May 2013 14:30

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Thanks!

Yes, I think I need to determine the lat/long of the center position of the screen to find out if another tile needs to be downloaded, hence the pixel coordinate question. Drag the viewport to edge of tile, create a new tile sort of thing.

I got sidetracked trying to make the Editboxes play nice with being Fixed to the screen, hence the hidden sprites setting the Editbox's focus when tapped on.

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AppGameKit Classic Chat / Baxslash Pinch Zoom with Google Maps

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