How do I script a new white layer to the bottom of the layer stack

kes · **Joined:** Oct 06, 2017 **Posts:** 16

I'm a gimp script-fu beginner and have had a good search for this on google, with nothing coming up so far.

How do I script a new white layer that matches the size of the existing single layer and places this at the bottom of the current layer stack, underneath everything else.

It looks like it might be "gimp-layer-new", or something like that, from the procedure browser, but I have not been able to figure out a command that works.

I do this repeatedly and it makes sense to put this into a script and assign a keyboard shortcut.

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

"gimp-layer-new" followed by "gimp-image-insert-layer", where the 4th argument is the count of layers -1.

Without scripting, there are some quick ways to move a layer to the bottom:

* Layer > Stack > Layer to bottom" (for which you can define a shortcut if necessary, see "Edit > Keyboard shortcuts")
* Shift-click the "V" icon at the bottom of the layers list.

kes · **Joined:** Oct 06, 2017 **Posts:** 16

Thank you

I really don't get the command structure and have had a look

I put this

gimp-layer-new gimp-image-insert-layer 0 0 0 -1

Into the console and it did nothing

I've no idea whether that is the right format, or, what might go in place of the existing zeros.

I've found nothing that describes a white layer.

All that is wanted is what it does then you do this with the mouse

Pocholo · **Posted:** Thu Nov 10, 2022 2:06 pm **(#4)**

You should learn Python, because GIMP python it's easier to write.
Go to Jackson Bates GIMP python tutorial site here: https://jacksonbates.wordpress.com/pyth ... ial-pages/

You will create a plugin script in no time.

teapot · **Joined:** Dec 09, 2018 **Posts:** 734

kes,

I think the position you want for the bottom of the layer stack is the count of layers. Not the count of layers -1.

Agree with the above that Python is easier to write so worth switching to that, but since you are already using scheme below is a simple go at the basics.

If you are using layer groups you may want the background layer at the bottom of the group instead. Also you may want the original active layer made active again.

Code: Select all

(define (script-fu-add-background-layer image drawable)

  (gimp-image-undo-group-start image)

  (let* ((width (car (gimp-drawable-width drawable)))
         (height (car (gimp-drawable-height drawable)))
         (num-layers (car (gimp-image-get-layers image)))
         (background-layer (car (gimp-layer-new image width height RGBA-IMAGE "Background" 100 LAYER-MODE-NORMAL)))
         (offsets (gimp-drawable-offsets drawable))
         (offx (car offsets))
         (offy (cadr offsets)))

    (gimp-drawable-fill background-layer FILL-WHITE)
    (gimp-image-insert-layer image background-layer 0 num-layers)
    (gimp-layer-set-offsets background-layer offx offy))

  (gimp-image-undo-group-end image)
  (gimp-displays-flush))

(script-fu-register
  "script-fu-add-background-layer"            ; Name
  "Add a background layer"                    ; Menu label
  "Add a white layer at the bottom of the layer stack."  ; Description
  "Author"                                    ; Author
  "Copyright"                                 ; Copyright
  "Nov 2022"                                  ; Date
  "*"                                         ; Types
  SF-IMAGE       "Input image"     0
  SF-DRAWABLE    "Input drawable"  0
)

(script-fu-menu-register "script-fu-add-background-layer" "<Image>/Layer")

kes · **Joined:** Oct 06, 2017 **Posts:** 16

Pocholo wrote:

You should learn Python, because GIMP python it's easier to write.
Go to Jackson Bates GIMP python tutorial site here: https://jacksonbates.wordpress.com/pyth ... ial-pages/

You will create a plugin script in no time.

Thank you. I will do this when I have time. The pointer to the link appreciated.

kes · **Joined:** Oct 06, 2017 **Posts:** 16

ofnuts wrote:

"gimp-layer-new" followed by "gimp-image-insert-layer", where the 4th argument is the count of layers -1.

Without scripting, there are some quick ways to move a layer to the bottom:

* Layer > Stack > Layer to bottom" (for which you can define a shortcut if necessary, see "Edit > Keyboard shortcuts")
* Shift-click the "V" icon at the bottom of the layers list.

thank you

kes · **Joined:** Oct 06, 2017 **Posts:** 16

teapot wrote:

kes,

I think the position you want for the bottom of the layer stack is the count of layers. Not the count of layers -1.

Agree with the above that Python is easier to write so worth switching to that, but since you are already using scheme below is a simple go at the basics.

If you are using layer groups you may want the background layer at the bottom of the group instead. Also you may want the original active layer made active again.

Code: Select all

(define (script-fu-add-background-layer image drawable)

  (gimp-image-undo-group-start image)

  (let* ((width (car (gimp-drawable-width drawable)))
         (height (car (gimp-drawable-height drawable)))
         (num-layers (car (gimp-image-get-layers image)))
         (background-layer (car (gimp-layer-new image width height RGBA-IMAGE "Background" 100 LAYER-MODE-NORMAL)))
         (offsets (gimp-drawable-offsets drawable))
         (offx (car offsets))
         (offy (cadr offsets)))

    (gimp-drawable-fill background-layer FILL-WHITE)
    (gimp-image-insert-layer image background-layer 0 num-layers)
    (gimp-layer-set-offsets background-layer offx offy))

  (gimp-image-undo-group-end image)
  (gimp-displays-flush))

(script-fu-register
  "script-fu-add-background-layer"            ; Name
  "Add a background layer"                    ; Menu label
  "Add a white layer at the bottom of the layer stack."  ; Description
  "Author"                                    ; Author
  "Copyright"                                 ; Copyright
  "Nov 2022"                                  ; Date
  "*"                                         ; Types
  SF-IMAGE       "Input image"     0
  SF-DRAWABLE    "Input drawable"  0
)

(script-fu-menu-register "script-fu-add-background-layer" "<Image>/Layer")

Thank you. Really appreciated. Saved me a tonne of time with a very repetitive task across many many files, where I had to add a white layer to the lowest part of the layer stack.

Script-fu seems convoluted though I am sure it is not if you have time to get into it.

I can see at some time I will have to learn python gimp scripting, when I get a moment.