QEasingCurve: fix qFuzzyCompare use in TCBPoint's op==HEADdev

qFuzzyCompare() requires that neither argument is numerically
zero. This cannot be guaranteed for the parameters of a "TCB" spline;
indeed, Wikipedia says t = b = c = 0 is "the default":
  https://en.wikipedia.org/wiki/Kochanek%E2%80%93Bartels_spline#Parameters_and_Effects

Fix by using the new QtPrivate::fuzzyCompare() function, which does
things in the correct way.

As a drive-by, put the operators at the beginning of continued lines,
as requested by https://wiki.qt.io/Qt_Coding_Style#Line_breaks Item 2,
make the operator a hidden friend instead of a member function, and
explicitly use qFuzzyCompare() instead of operator== for the QPointF
member.

The latter drive-by change will need to be dropped from the 6.5
pick-to, because the overload didn't exist in 6.5, yet (added by
fa0d77e290f5ccb5afa7d02716f8726aa6b810e6 for 6.8).

Amends b9f0bde16e85161666d5090952955bebacc40f89.

Pick-to: 6.11 6.10 6.8 6.5
Task-number: QTBUG-142020
Change-Id: I76d1adefd39154d7a39454d676dbfd5dfcaf9c1d
Reviewed-by: Edward Welbourne <[email protected]>

0 files changed, 0 insertions, 0 deletions