Is this the proper code for adding a 7pt curve to an image?


Or should the x and y pts be closer together like this?

Or perhaps this?

I think i figured it out.

EDIT: I had some bad information in this post originally and have updated it to be more accurate. In particular, one can no longer pass lists to the PDB when it is expecting vectors (you used to be able to do this way back when).

In Script-fu, you do not use commas to separate elements in a list. Just use spaces, tabs, and newlines. Also, if your list contains any variable names then you do not want to quote your list with the apostrophe; instead you will want to use the 'list' function.

For example,


As to the format for specifying a seven-point spline curve, the x and y coordinates follow the values that would appear in the corresponding Curves Tool graph as shown below (the text box in the upper-left contain the coordinates of the second point of the curve, circled in red).


The list should contain a series of alternating x and y values, each x corresponding to that point's horizontal position in the above graph and the y corresponding to the vertical position. To be safe, the x coordinate of the first point should always be "0", and of the last point it should always be "255".

For the seven points listed, the spline curve would be the list: '(0 0 32 160 64 96 96 192 160 64 192 224 224 32) with x coordinates shown in blue and y in red.


Alternately, you could use #(...) to build your vector out of constants. It behaves analogously to how '(...) works for lists of constants.


If you've assigned those values to variables, or you've calculated them algorithmically, then you will have to use 'vector' to create your vector, instead of just quoting it ('vector' work just like 'list' but produces a vector instead of a list).

Examples gimp-curves-spline :
crystal-logo.scm
neon-logo.scm
sota-chrome-logo.scm

Thank you Saulgoode and Sam.

I have also seen it written this way.


So what is the correct way to just call the curves tool with those points i have? Like this?


Or do i have to use cons to construct an array of pts?

Rod, I had so much bad information in my previous post, I have edited it to correct the errors. Please read it again as I think it now addresses your questions. (If not, I will be glad to elaborate.)

Thanks for all your help Saulgoode. I think i have it now.


That should do it.

Except that the procedure to convert a list to a vector should be 'list->vector'. I've been playing around a lot with GIMP paths lately and it has damaged my brain. A GIMP path is now called a 'vectors' (but a GIMP 'vectors' is a completely different animal than a Scheme 'vector').

Ahh i was wondering why the list>vectors wasn't changing color, and the script wouldn't show in the menus.
Thanks i changed it to vector.

Eat some smoked fish and that will help your brain. Not to mention its pretty tasty.