GIMP RetroSun

retrosun.py

#!/usr/bin/env python

from gimpfu import *

def retrosun(img, layer, gradient):
    gimp.progress_init("Rendering RetroSun to " + layer.name + "...")

    # Set up an undo group, so the operation will be undone in one step.
    pdb.gimp_undo_push_group_start(img)

    # Do stuff here.
    try:
        exists, x1, y1, x2, y2 = pdb.gimp_selection_bounds(img)
        w, h = x2 - x1, y2 - y1

        assert exists

        pdb.gimp_image_select_ellipse(img, CHANNEL_OP_REPLACE, x1, y1, x2 - x1, y2 - y1)
        pdb.gimp_drawable_edit_gradient_fill(
            layer,
            GRADIENT_LINEAR,
            0,
            0,
            0,
            0,
            0,
            (x1 + (x2 / 2)),
            y1,
            (x1 + (x2 / 2)),
            y2,
        )
        
        pdb.gimp_selection_clear(img)

        cut_at = round(h / 3) # start at 1/3 of the circle

        i = h - cut_at # subtract that 1/3 from the full circle's height
        size = round(h / 30) # the size of the cutout
        size_step = round(size / 5) # cutout size step for every step

        distance = size * 2 # distance is double the original cutout size
        distance_step = size_step # distance step size increase is the same as for the size

        while i >= 0:
            pdb.gimp_image_select_rectangle(img, CHANNEL_OP_ADD, 0, cut_at, img.width, size)
            
            size += size_step
            distance -= distance_step

            cut_at += (size + distance)
            i -= (size + distance)
        
        pdb.gimp_edit_fill(layer, FILL_TRANSPARENT)
        pdb.gimp_selection_clear(img)
    except AssertionError:
        pass
    finally:
        # Close the undo group.
        pdb.gimp_undo_push_group_end(img)


register(
    "RetroSun",
    "Create a Retrowave Sun at Selection",
    "Create a Retrowave Sun at Selection",
    "Synthehol FM",
    "funbaker",
    "2022",
    "<Image>/Filters/Render/RetroSun",
    "*",      # Alternately use RGB, RGB*, GRAY*, INDEXED etc.
    [
        (PF_GRADIENT, "gradient", "Gradient", None)
    ],
    [],
    retrosun
)

main()