export to image with overlays

Hi Piotr,

I have come up again against a small bug in the image export of MINERVA. When the ‘export as image’ function is used, the overlay colourings are not correct so the exported maps look different to those in the MINERVA browser. (I also notice that edges with one vertex outside the visible area are not drawn).

For the colouring, it appears that the extreme colours for positive and negative values are correct but they are being faded invariably through black rather than through the colour defined by "Overlay color for value=0”. This latter colour is always exported as white regardless of the setting in MINERVA. I suspect this is quite an easy fix.

Please let me know if I can provide any other useful info for debugging. Cheers and have a happy start to the New Year!

Rupert