Feature Request - Option for alternative G code format: G2 Xn Yn In Jn

[printhefuture]

Is it possible to add code, and a user selectable option, for the G2 / G3 code outputs to have the alternative format, which uses X, I, J instead of X, I, R?

E.g.
Current Output: G3 X2 Y7 R5
Alternative Output: G3 X2 Y7 I-4 J-3

The benefit will be saving many processor cycles on boards without FPUs. This is due to the current code in Marlin's G2_G3.cpp (v2.07). Every time a G2 / G3 is encountered, it does alot of expensive math ops, these ops aren't needed with the alternative format.

The (small) downside of this request - apart from you coding it - is a slight increase in processing time when ArcWeld does it's business.

As an aside, I'm currently re-writing G2_G3.cpp with a bunch of other optimisations for boards that don't have FPUs.

Thanks!

[FormerLurker]

Are you sure you don't have it backwards? ArcWelder always outputs X Y I J now. It would be extremely easy to output the X Y R form, especially since I already have to calculate the radius. In fact, I actually convert R to I J as a final step.

Now, the X Y R form has less support, but I don't see any problem adding an option for it. It will reduce the gcode size even further if it's supported.