This implements basic color grading modifiers in sequencer, supporting
color balance, RGB curves and HUE corrections.
Implementation is close to object modifiers, some details are there:
http://wiki.blender.org/index.php/User:Nazg-gul/SequencerModifiers
Modifiers supports multi-threaded calculation, masks and instant
parameter changes.
Also added cache for pre-processed image buffers for current frame,
so changing sequence properties does not require rendering of original
sequence (like rendering scene, loading file from disk and so)
This implements option which could be used to color balance only
specified area. Currently done by adding Mask input to Adjustment
effect. Affects on color balance and multiply settings.
Supporting masked saturation control is in the list, not supported
in this commit.
Also show value slider in the right of color wheel.
Added a framework to run effects in several threads. Port most
of effects to this new framework.
Still some work to be done here (some effects are not so easy to port)
Before this the the whole sequencer cache would be invalidated
when hanging sequence settings.
This was completely annoying because changing color balance
settings would re-load image file for which color balance
is happening on every change,
In fact it's still an issue if color balance is changing for
image strip itself, but if this strip has got effect and
color balance is changing for it file wouldn't be reloaded.
Should give some more realtime update, but it's currently not the
biggest issue - changing color balance settings would imply reloading
of file which is slow. Would be investigated further.
This change shouldn't affect on pre-fetching job which is already
multi-threaded and doing threaded color balance would make things
only worse.
* Remove all code for Texture and Sequencer plugin system, this never worked in 2.5x / 2.6x and is therefore not needed anymore.
* DNA structures are kept, all read/writefile code is gone.
... instead add scene.sequencer_editor_create / clear, these match id.animation_data_* functions.
- refactor for names, for scene level functions call them BKE_sequencer_*
