Marking/drawing atop a graphic
Hi, I have a little app for foresters who generally use their iPad Minis out in the deep woods without internet access. I am able to cache maps from Google for them before-hand, including the relevant pre-loaded lats and longs they intend to visit, and I'd like to have atop those graphic files a FileMaker Go-drawn set of indicators of some lats and longs that they are adding as they go along.
I can sort of do this by superimposing a scatter plot chart of lats and longs customized to a transparent background on top of a graphic held in a container, but as the locations of the points inside this square change, the two elements get out of alignment (we have complete control over the Google map, but the Filemaker chart appears to jitter around a bit, even if you have the same four extreme corners set as points within the chart consistently. Something about the other points in the chart moving about makes Filemaker push the chart graphic a little here and there.)
A screenshot is included here of the little green dots from a scatter plot map I have superimposed on a google map. It works fine for a single set of points and scale, but not for a variable set of points.
So I'm asking if there is a different way of somehow having control over a graphic or layout element that would allow us to effectively draw dots or pins, etc. atop a graphic file? We know precisely how many pixels over we need to draw the dots; it's just that we need control over some layout object or other element that we can move around visually. Anyone have any ideas?
Thanks for your help, -Tig