...and present linear RGB Histograms
This is step one: implement the feature at all (without new defaults
or proper GUI, cough).
Add boolean "linear" properties to GimpOperationPointFilter,
GimpCurvesConfig and GimpLevelsConfig.
In the filter, simply set the input/output formats to linear in
prepare().
In the curves and levels tools, add "Linear" toggles from hell,
like in the histogram dockable, and make sure things work right
wrt changing and resetting the property, switching from levels
to curves, and picking colors.
The result currently changes when switching a non-nop curves/levels
between perceptual and linear, because adjusting the parameters
between the spaces is not implemented yet.
Add "clamp-input" (which clamps the input values to [0..1])
and "clamp-output" (which clips the final result to [0..1]),
properties, parameters and GUI to:
- GimpLevelsConfig
- GimpOperationLevels
- The levels tool dialog
- The gimp_drawable_levels() PDB API
The old deprecated gimp_levels() PDB API now sets both clamping
options to TRUE which restores the 2.8 behavior.
Also reorder some stuff in GimpLevelsConfig and elsewhere so the
levels parameters are always in the same order.
It was misnamed from the beginning and has no relation to GimpImageMap
except that it happens to be used by GimpImageMapTools. Now it feels
less weird to potentially use it for other settings too.
