4 ms·
right，an internal rezeroed south east system makes it match the graphics system. So pixel positions and coordinates covary and are always positive. It makes deb
by geokon 5y ago
right，an internal rezeroed south east system makes it match the graphics system. So pixel positions and coordinates covary and are always positive. It makes debugging a million times easier
More radical would be to go from degrees to the 0 UINT_MAX range and have your unsigned values automatically wrap around. You'd have the range wrap around naturally. But it's nice to have degrees for debugging and it's not tied to a type so you can have arbitrary precision. I also think you'd still have corner cases to deal with (but I'll have to think about this some more)
- iopq 5y agoWhy not signed?
- geokon 5y agoyeah, good question. My limited experience has shown me that you end up coding in assumptions that make the sign flip problematic :). There are all those infamous cases of systems crashing on planes and ships when they cross the equator. Ideally you'd test in all four quadrants of the globe but this ends up being cumbersome. There is also the convenience of having your coordinates change in the same way as your display coordinates. So if something displays off of where it should then you can easily diagnose the problem. Everything is always in units of degrees relative to the top left corner (with maybe a scale factor) - whether you're looking at the whole globe or just a region. With a signed coordinate you'd be relative to the image center which is not how your display works. You need to track offsets and image widths/heights. Debugging gets nastier and you have off by one problems and whatnot. That's just been my experience so far
- iopq 5y agoThat's what I'm saying, you map the negative latitude and longitude to negative numbers