Since CIE Lab is one of the supported color spaces for doing the blending -
this enum is not only about transfer functions/curves or gamma. This finishes
already started cleanups.
... in status bar.
Follow-up of commits f836892 and d1c3c3d. With high resolutions, the
distance displayed in the status bar when shift-clicking in a paint tool
may lack digit precision and show the same value (in non-pixel unit) for
several consecutive pixels. Compute a more accurate precision than what
gimp_unit_get_digits() can provide in such cases.
When working with high resolution, you may have cases where measured
length won't be displayed with enough digits; i.e. several pixels length
would show up as 0. For instance at 4000 PPI, up to 7 pixels show up as
0 mm, then at 0.1 mm from the 8th pixel (actually reaching over 0.05 mm,
approximating as 0.1), then 0.2 at 24 pixels (actually: 0.152), and so
on. At such a resolution, 3 digits are needed for 'mm' instead of the
1 digit returned by gimp_unit_get_digits() so that we display reliable
lengths.
Therefore we need to compute ideal digit precision. Configured digits
for a given unit will now be used as a minimum value, but actually used
digits may be higher.
Compute the ideal decimal precision for cursor position and length
status so that you get the best precision on physical units depending
on the current resolution, yet avoiding over-precision (which can be
misleading). The unit's "digits" value is now used as a minimum
precision only.
It is used both for blending and compositing, the repeated use of the word
BLEND in code made the logic involving both blending and compositing hard to
read.
Note that in some cases the alloca may be unnecessary, but this keeps
the code clean, and we have to be able to *potentially* do the alloca
anyway, so what the hell.
Implement a common utility function gimp_blend_composite that uses utility
functions for implementing layer modes, with separate (possibly SIMD) optimized
loops for blending and compositing, with configured linear TRC, perceptual
gamma TRC or even using CIE Lab as the space.
When working in high bitdepth, manually changing precision to 8bit or 16bit is
an extraenous step, this adds a conversion step - but doesn't permit dithering
- and also doesn't permit using the palette modes of PNG. However it makes
workflows with single precision linear floating point much more usable.
from gimp_applicator_new() and gimp_gegl_mode_node_set_mode().
Compositing doesn't depend on the layer format any longer, only on the
layer mode. Painting with "use applicator" unchecked is still broken
in some cases and needs more fixing.
like all other function typedefs and add GimpBlendFunc typedef which
will be needed soon. Also rename get_layer_mode_function() to
gimp_get_layer_mode_function().
Michael Natterer