Maybe I'm not right here with my question and maybe it's a stupied question.
I want to get the x,y position under the mouse cursor in an xy chart. I find several solutions on this board, but they nearly always fall back on introducing a variable type TDoublePoint.
If I do this, I get the error : Identifier not found "TDoublePoint".
I'm using Lazarus 1.6 under Windows 10 and Linux and get the same error.
Did I forget something?
Any help would be appreciated.