Render duotone button plugin in GIMP

button-render.py

# Copyright 2021 Ali Sherief
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

#!/usr/bin/python
from gimpfu import *
def button_render(image, threshold, x, y, is_nonrectangular):
    pdb.gimp_image_undo_group_start(image)
    # This plugin expects there be exactly 3 layers - no more, no less.
    if len(image.layers) != 3:
      raise RuntimeError("This plugin only supports 3 layers")
    layer3 = image.layers[0]
    layer2 = image.layers[1]
    layer1 = image.layers[2]
    # Save the old threshold and criterion here so we can restore them 
    old_threshold = pdb.gimp_context_get_sample_threshold_int()
    old_crit = pdb.gimp_context_get_sample_criterion()
    old_fgcolor = pdb.gimp_context_get_foreground()
    old_opacity = pdb.gimp_context_get_opacity()
    old_brush = pdb.gimp_context_get_brush()
    pdb.gimp_context_set_sample_threshold_int(threshold)
    pdb.gimp_context_set_sample_criterion(SELECT_CRITERION_V)
    pdb.gimp_context_set_foreground((255,255,255))
    pdb.gimp_context_set_opacity(100)
    # Preserve as much as the old brush state as we can. The options
    # "Apply Jitter", "Incremental", "Hard Edge", "Smooth Stroke" and
    # "Lock Brush To View" cannot be programmatically changed, but
    # these should all be off for the effect to work!
    old_brush_size = pdb.gimp_context_get_brush_size()
    old_brush_dynamics = pdb.gimp_context_get_dynamics()
    old_brush_force = pdb.gimp_context_get_brush_force()
    new_brush = pdb.gimp_brush_duplicate('2. Block 03')
    pdb.gimp_context_set_brush(new_brush)
    pdb.gimp_brush_set_aspect_ratio(new_brush, 20.0)
    pdb.gimp_brush_set_angle(new_brush, 0.0)
    pdb.gimp_brush_set_hardness(new_brush, 95.0)
    pdb.gimp_brush_set_spacing(new_brush, 10.0)
    pdb.gimp_brush_set_shape(new_brush, BRUSH_GENERATED_CIRCLE)
    pdb.gimp_context_set_brush_size(180.0)
    pdb.gimp_context_set_dynamics("Dynamics Off")
    pdb.gimp_context_set_brush_force(0.5)
    # Get dimentions of this image so we can create two new images of the same size.
    # It also helps with creating channels as the width and height are needed there.
    ch = pdb.gimp_channel_new(image, image.width, image.height, "_button_render_highlights", 100, (0,0,0))  # black
    image.add_channel(ch)
    # Now we make the selection...
    pdb.gimp_image_select_contiguous_color(image, CHANNEL_OP_REPLACE, layer1, x, y)
    pdb.gimp_selection_invert(image)
    # ...Then we fill the selection inside the channel completely white...
    pdb.gimp_edit_bucket_fill(ch, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
    # ...And then we slightly expand the selection to half-select the immediately surrounding pixels...
    pdb.gimp_selection_grow(image, 1)
    pdb.gimp_edit_bucket_fill(ch, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 50, 0, False, 0, 0)
    # ...And we do this a second time.
    pdb.gimp_selection_grow(image, 1)   
    pdb.gimp_edit_bucket_fill(ch, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 50, 0, False, 0, 0)
    # And now our mask is ready!
    # But first we make a bevel around the three layers.
    pdb.gimp_selection_none(image)
    pdb.gimp_image_set_active_layer(image, layer1)
    pdb.script_fu_add_bevel(image, layer1, 5, False, False)
    pdb.gimp_image_set_active_layer(image, layer2)
    pdb.script_fu_add_bevel(image, layer2, 5, False, False)
    pdb.gimp_image_set_active_layer(image, layer3)
    pdb.script_fu_add_bevel(image, layer3, 5, False, False)
    # If the button has transparent parts then we need to take
    # that into account when creating the border.
    # Otherwise we can do a simple select all followed by shrink
    # to get the border selection.
    pdb.gimp_selection_all(image)
    pdb.gimp_selection_shrink(image, 1)
    pdb.gimp_selection_invert(image)
    # Create a channel and fill it with the selection.
    ch_rect = pdb.gimp_channel_new(image, image.width, image.height, "_button_border_rect", 100, (0,0,0))  # black
    image.add_channel(ch_rect)
    pdb.gimp_edit_bucket_fill(ch_rect, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
    if is_nonrectangular:
        # Non-rectangular buttons need a little more work to select the bounded parts.
        pdb.gimp_image_select_item(image, CHANNEL_OP_REPLACE, layer1)
        ch_work = pdb.gimp_channel_new(image, image.width, image.height, "_button_border_work", 100, (0,0,0))  # black
        image.add_channel(ch_work)
        pdb.gimp_edit_bucket_fill(ch_work, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
        pdb.gimp_selection_invert(image)
        pdb.gimp_selection_grow(image, 1)
        pdb.gimp_image_select_item(image, CHANNEL_OP_INTERSECT, layer1)
        ch_round = pdb.gimp_channel_new(image, image.width, image.height, "_button_border_round", 100, (0,0,0))  # black
        image.add_channel(ch_round)
        pdb.gimp_edit_bucket_fill(ch_round, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
        pdb.gimp_image_select_item(image, CHANNEL_OP_REPLACE, ch_work)
        pdb.gimp_image_select_item(image, CHANNEL_OP_INTERSECT, ch_rect)
        pdb.gimp_image_select_item(image, CHANNEL_OP_ADD, ch_round)
    ch_border = pdb.gimp_channel_new(image, image.width, image.height, "_button_border", 100, (0,0,0))  # black
    image.add_channel(ch_border)
    pdb.gimp_edit_bucket_fill(ch_border, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
    # Make the background
    pdb.gimp_image_select_item(image, CHANNEL_OP_REPLACE, ch_border)
    pdb.gimp_context_set_foreground((204, 204, 204)) #cccccc
    pdb.gimp_edit_bucket_fill(layer1, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
    pdb.gimp_context_set_foreground((230, 230, 230)) #e6e6e6
    pdb.gimp_edit_bucket_fill(layer2, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
    pdb.gimp_context_set_foreground((255, 255, 255)) #ffffff
    pdb.gimp_edit_bucket_fill(layer3, BUCKET_FILL_FG, LAYER_MODE_NORMAL, 100, 0, False, 0, 0)
    # Make a copy of the first layer as a new image
    pdb.gimp_selection_all(image)
    pdb.gimp_edit_copy(layer1)
    image_1 = pdb.gimp_edit_paste_as_new_image()
    display_1 = pdb.gimp_display_new(image_1)
    # Now we apply Dodge effect on all the layers using the selection
    # For some reason, image.height only dodges the top half of the image.
    # Not sure if this is also true with image.width (left-half part) but multiplying
    # by two just in case (the dodge brush should be centered on the x-axis i.e. half of width).
    pdb.gimp_image_select_item(image, CHANNEL_OP_REPLACE, ch)
    alist = []
    for i in range(1, image.height*2):
        alist += [image.width, i]
    pdb.gimp_image_set_active_layer(image, layer1)
    pdb.gimp_context_set_opacity(30)
    pdb.gimp_dodgeburn(layer1, 50, DODGE_BURN_TYPE_DODGE, TRANSFER_MIDTONES, image.height*2, alist)
    pdb.gimp_image_set_active_layer(image, layer2)
    pdb.gimp_context_set_opacity(50)
    pdb.gimp_dodgeburn(layer2, 50, DODGE_BURN_TYPE_DODGE, TRANSFER_MIDTONES, image.height*2, alist)
    pdb.gimp_image_set_active_layer(image, layer3)
    pdb.gimp_context_set_opacity(70)
    pdb.gimp_dodgeburn(layer3, 50, DODGE_BURN_TYPE_DODGE, TRANSFER_MIDTONES, image.height*2, alist)
    # Now make a copy of the third layer as a new image
    pdb.gimp_selection_all(image)  # Remove this to select and copy the button labels.
    pdb.gimp_edit_copy(layer3)
    image_3 = pdb.gimp_edit_paste_as_new_image()
    display_3 = pdb.gimp_display_new(image_3)
    pdb.gimp_selection_none(image)
    # Hide the channels
    if is_nonrectangular:
        pdb.gimp_item_set_visible(ch_work, False)
        pdb.gimp_item_set_visible(ch_round, False)
    pdb.gimp_item_set_visible(ch, False)
    pdb.gimp_item_set_visible(ch_rect, False)
    pdb.gimp_item_set_visible(ch_border, False)
    # Restore the state
    pdb.gimp_context_set_sample_threshold_int(old_threshold)
    pdb.gimp_context_set_sample_criterion(old_crit)
    pdb.gimp_context_set_foreground(old_fgcolor)
    pdb.gimp_context_set_opacity(old_opacity)
    pdb.gimp_context_set_brush(old_brush)
    pdb.gimp_context_set_brush_size(old_brush_size)
    pdb.gimp_context_set_dynamics(old_brush_dynamics)
    pdb.gimp_context_set_brush_force(old_brush_force)
    pdb.gimp_image_undo_group_end(image)


register(
        "button_render",
        "Render a duotone button, making unpressed, pressed, and animated click images",
        "Render a duotone button, making unpressed, pressed, and animated click images",
        "Ali Sherief <ali@notatether.com>",
        "Ali Sherief <ali@notatether.com>",
        "2021",
        "Button Render",
        "RGB",        # Adjust for other types when code is more flexible
        [
		(PF_INT, "threshold", "Select Color Threshold", 12),
		(PF_INT, "x", "X Sample Coordinate For Background Detection", 1),
		(PF_INT, "y", "Y Sample Coordinate For Background Detection", 1),
		(PF_BOOL, "is_nonrectangular", "Non-rectangular button", False)
        ],
        [],
        button_render,
        menu="<Image>")

#gimp.image_list() gets list of all open images