On 29-Nov-2002, Raphaël Quinet wrote: > However, here is my point of view (which may be different from what > some other developers think, so do not take this for granted). There > are two kinds of "grouping": > > - Simple linking of layers so that some operations such as toggling > their visibility or moving the whole group of layers can easily be > applied to them (bug #86337, bug #86277). These operations would > not modify the pixels in the layers. This could probably also be > used for implementing the clipping groups (bug #51112). > > - Grouping of layers in such a way that a merged image of the layers > is stored in a virtual layer and some operations can be applied to > this merged layer: color adjustments, transformations or even any > PDB operation, including the ones done by a plug-in. Whenever a > layer in the group is modified, the merged image is rebuilt and the > operation associated with it is applied to in order to re-create the > updated "active layer". This can be used to implement the Photoshop > styles or adjustment layers (bug #79025, bug #98262). In summary, > the "active layer" would have a list of layers, a drawable and one > PDB function (with its current parameters) associated with it. > Whenever something happens to one of the layers in the list, a new > (invisible) drawable is allocated, it gets the merged copy of all > layers, and then the PDB function is applied to it. When the > results are ready, the new drawable replaces the one that was > visible. In some cases, it may be better to keep the two drawables > (merged view + results) and to apply the PDB function only to the > regions that have been modified, but this is only an optimization. > > So as you mentioned yourself, there are two ways to define "groups": > they have different purposes and need to be implemented differently. > That is a _perfect_ explination of what I want. =) -- Patrick "Diablo-D3" McFarland || unknown@xxxxxxxxx "Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music." --Kristian Wilson, Nintendo, Inc, 1989
Attachment:
pgpNV7nQI43Wj.pgp
Description: PGP signature
