this is not required since we check this already in line 892.

this logic is not quite correct since we can have DateTime on the x-axis and Numeric or Integer on the y-axis or the other way around.

wouldn't an 'or' be even better here?

Please put 'continue' to the next line.

What is the reason for this if?

use std::swap(startIndex, endIndex)

one tab too much here. Please also break the parameters, let's avoid such long lines.

remove these empty lines.

minLogicalDiffY is not used in this function.

samePixel() is only used once here. Let's add this logic directly inside of XYCurvePrivate::addLine().

we don't use brackets for one-line statements.

remove this empty line.

use std::swap(startIndex, endIndex)

this part comes after the break. Is this intended?

this part comes after the break. Is this intended?

Because the logical points are not needed, if no symbols nor values are visible. To save computational power

no

no

symbolPointsLogical is also used in updateErrorBars(), updateDropLines() and in updateFilling(). So, even if we don't show any symbols and values, we still need these points for error bars, for the drop lines and for the filling below/above the curve.