On 08/27/2010 08:05 PM, Jacopo Corzani wrote:

Hello,
i think that would be very useful a dummy layer that can contains a particular effect/operation like curves in order to change parameters in future without any problems and eventually using a particular mask for handle particular zone where i don't want this.
In this case is possible to activate or deactivate effects and change that parameters dynamically without any duplicate image layers with static effects. The problem may be in a user-defined plugins but for standard operation like levels or curves there isn't or i'm missing somethings? If i write an effect plugin would be perfect to associate that with this kind of dummy layer in order to change parameters/enable/disable/masking/unmasking that whenever i want. Sorry for my english :),i'm not a mother language...

Jack

On Fri, 2010-08-27 at 20:58 -0400, Brian Vanderburg II wrote:

[...] I would love to see something like that in GIMP, as well as something like layer groups

Do the current (2.7.x) layer groups not meet your needs?

Liam

On 08/27/2010 10:15 PM, Liam R E Quin wrote:

On Fri, 2010-08-27 at 20:58 -0400, Brian Vanderburg II wrote:

[...] I would love to see something like that in GIMP, as well as something like layer groups

Do the current (2.7.x) layer groups not meet your needs?

Liam

They probably do. I haven't had a chance to try any of the new features yet. On Debian 5 I'll have to compile babl and gegl, and install a newer intltool before compiling GIMP 2.7.

Brian Vanderburg II

On Sun, Aug 29, 2010 at 4:24 AM, Jacopo Corzani wrote:

Well, adjustment layers is what GIMP developers seem to refer to as "layer abuse" :)

There are different ways to implement non-destructive editing. Would you be interested to find out more?

Alexandre Prokoudine http://libregraphicsworld.org

Hi Alexandre,
i could agree with your consideration of "layer abuse" but adjustment layer is a quick and robust solution to manage effects whenever i want. Changing a curve (or any other "effect") dynamically without duplicate layers would be a great.
Sure,i'm interested to find another quick way to handle "effects" during time without do an layer abuse, but i don't have any ideas that speed up work like adj layers... :)
Thanks for your response.

Peter Sikking has already expressed a way of doing this: you attach a list of effects to a layer or layer group.

http://www.mmiworks.net/eng/publications/2007/05/lgm-top-gimp-user-requests_25.html

As he observes, this avoids the problem of 'adjustment layers' not actually being layers in any normal sense (that is, their lack of content) while allowing the same or greater functionality.

On Sun, Aug 29, 2010 at 12:39 PM, Jacopo Corzani wrote:

http://www.mmiworks.net/eng/publications/2007/05/lgm-top-gimp-user-requests_25.html

As he observes, this avoids the problem of 'adjustment layers' not actually being layers in any normal sense (that is, their lack of content) while allowing the same or greater functionality.

This kind of layer's effect stack is currently under develpment (you post is dated to may 2007)? . It can be a great step to make gimp totally non destructive and easy to use.If this feature is under devel i would contribute in a development or test phase. Anyone know anything?There is an open task about that?

There is an ongoing architecture refactoring of GIMP towards migrating the internal representation of buffers (or rather what is traditionally seen by the user as layers) and all processing happening on them to use GEGL (http://gegl.org/). An initial refactoring has been done for color processing tools and the processing of the layer stack. This can be enabled by the user through the menus of the development version.

Once GIMP uses GEGL by default for the composition of the layers adding any GEGL based operation as a filter on a layer is easy from a programming perspective. I have myself done an experiment where I replaced the per opacity slider in the layers dialog with a gaussian blur and it works as expected for both text and other layers.

The UI for this is not fully decided upon, and when it comes to the UI side and this proclaimed "layer-abuse", I am personally in favor of adding adjustment layers within the layer tree. This keeps the flow of compositing in one place in the UI, making it more readable. The styling and interactions with these operations can be a bit different from the actual content layers, allowing to collapse the list, simplifying the layers dialog to a tree of just the "content layers". Having this chain embedded within the layer tree solves an otherwise problematic recursion issue if the list is kept external to the layer tree, you want to be able to use layer subtrees as masks/parameters for operations performed on a layer or layer-group. Note that the transition to GEGL would also also enable you to use other render nodes in addition to text like gradients, noise, fractals, checkerboards, vector layers and more.

Thus helping out with this refactoring, and improving both GEGL and how GIMP uses GEGL is probably what would be most beneficial.

One thing that probably would aid in accelerating the refactoring of various subsystems is adding a tile backend to GeglBuffer that is backed by a GIMP TileManager, This would simplify the code used during transitioning, at the moment proxy GEGL operations are used that both makes more code required and also adds some overhead that could be avoided.

/Øyvind K.
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