ipa: raspberrypi: Compute inverse of piecewise linear function

Add a method to the piecewise linear function (Pwl) class to compute
the inverse of a given Pwl. If the input function is non-monotonic we
can only produce a best effort "pseudo" inverse, and we signal this to
the caller.

Signed-off-by: David Plowman <david.plowman@raspberrypi.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
This commit is contained in:
David Plowman 2020-12-08 20:44:39 +00:00 committed by Laurent Pinchart
parent dbcf4d8247
commit 1a6a7d4a8e
2 changed files with 33 additions and 0 deletions

View file

@ -80,6 +80,9 @@ public:
};
PerpType Invert(Point const &xy, Point &perp, int &span,
const double eps = 1e-6) const;
// Compute the inverse function. Indicate if it is a proper (true)
// inverse, or only a best effort (e.g. input was non-monotonic).
Pwl Inverse(bool *true_inverse = nullptr, const double eps = 1e-6) const;
// Compose two Pwls together, doing "this" first and "other" after.
Pwl Compose(Pwl const &other, const double eps = 1e-6) const;
// Apply function to (x,y) values at every control point.