# Drop Shadow Advanced
# (copyLEFT) 2013 Andrey "Efenstor" Pivovarov. No rights reserved
# Copy freely, modify freely, spread the word and remeber me in your prayers

#!/usr/bin/env python

import math
from gimpfu import *


def deinit(img):
    pdb.gimp_undo_push_group_end(img)
    pdb.gimp_progress_end()
    pdb.gimp_displays_flush()


def smooth_norm_blur(img, layer, width):
    # Smooth gaussian blur with normailzation

    pdb.plug_in_gauss(img, layer, width-width/5, width-width/5, 0)
    pdb.plug_in_normalize(img, layer)

    pdb.plug_in_gauss(img, layer, width/5, width/5, 0)
    pdb.plug_in_normalize(img, layer)


def basic_proc(img, drawable, grp, name, color, opac, width, thick):
    # Copy the drawable
    layer = drawable.copy()
    layer.name = name
    pdb.gimp_image_insert_layer(img, layer, grp, -1)

    # Set opacity
    layer.opacity = opac

    # Get mask if exists
    mask = pdb.gimp_layer_get_mask(layer)
    if mask==None:
        # Alpha to mask
        mask = pdb.gimp_layer_create_mask(layer, ADD_ALPHA_MASK)
        pdb.gimp_layer_add_mask(layer, mask)

    # Color
    pdb.gimp_layer_resize_to_image_size(layer)
    fg = pdb.gimp_context_get_foreground()
    pdb.gimp_context_set_foreground(color)
    pdb.gimp_drawable_fill(layer, FOREGROUND_FILL)
    pdb.gimp_context_set_foreground(fg)

    # Blur
    smooth_norm_blur(img, mask, width)

    # Thickness
    cpts = [ 0, 0, 127, (thick/100)*255, 255, 255 ]
    pdb.gimp_curves_spline(mask, 0, 6, cpts)

    # Autocrop
    pdb.plug_in_autocrop_layer(img, mask)

    return layer


def flatten_layer_group(img, group):
    # Get the children, the parent and the position
    cnum, cids = pdb.gimp_item_get_children(group)
    parent = pdb.gimp_item_get_parent(group)
    pos = pdb.gimp_image_get_item_position(img, group)

    # Get name
    grpname = group.name

    # Merge down
    merged = gimp.Item.from_id(cids[0])
    for i in range(0, cnum-1, 1):
        merged = pdb.gimp_image_merge_down(img, merged, EXPAND_AS_NECESSARY)

    # Move out the merged layer and remove the group
    pdb.gimp_image_reorder_item(img, merged, parent, pos+1)
    img.remove_layer(group)

    # Rename the layer
    merged.name = grpname

    return merged


def drop_shadow_advanced(img, drawable, uwidth, uopac, uthick, pwidth, popac, pthick, upoffx, upoffy, upcolor, vwidth, vopac, vthick, vcolor, intogroup, flatten):

    # Initialization
    from gimpshelf import shelf
    gimp.progress_init("Preparing...")
    pdb.gimp_undo_push_group_start(img)

    # Make the group
    grp = pdb.gimp_layer_group_new(img)
    if intogroup: grp.name = drawable.name+" + shadow"
    else: grp.name = drawable.name+" (shadow)"
    pos = pdb.gimp_image_get_item_position(img, drawable)
    par = pdb.gimp_item_get_parent(drawable)
    pdb.gimp_image_insert_layer(img, grp, par, pos+1)

    # Veil
    if vopac>0:
        # Do basic processing
        veil = basic_proc(img, drawable, grp, "Veil", vcolor, vopac, vwidth, vthick)

    # Penumbra
    if popac>0:
        # Do basic processing
        penumbra = basic_proc(img, drawable, grp, "Penumbra", upcolor, popac, pwidth, pthick)
        # Move
        penumbra.translate(upoffx, upoffy)

    # Umbra
    if uopac>0:
        # Do basic processing
        umbra = basic_proc(img, drawable, grp, "Umbra", upcolor, uopac, uwidth, uthick)
        # Move
        umbra.translate(upoffx, upoffy)

    # Move the object itself into the group
    if intogroup: pdb.gimp_image_reorder_item(img, drawable, grp, -1)

    # Flatten the group
    if flatten:
        shadow = flatten_layer_group(img, grp)
        pdb.plug_in_autocrop_layer(img, shadow)
    else: shadow = grp

    # Select the shadow
    img.active_layer = shadow

    # Deinitialization
    deinit(img)


register(
    "drop_shadow_advanced",
    "Produces a complex three-part drop shadow",
    "",
    "Efenstor",
    "(copyLEFT) Andrey \"Efenstor\" Pivovarov",
    "2013",
    "<Image>/Filters/Light and Shadow/Drop Shadow Advanced...",
    "RGB*",
    [
        (PF_INT, "uwidth", "Umbra width", 20),
        (PF_SLIDER, "uopac", "Umbra opacity", 50, (0, 100, 1)),
        (PF_SLIDER, "uthick", "Umbra thickness", 75, (0, 100, 1)),
        (PF_INT, "pwidth", "Penumbra width", 100),
        (PF_SLIDER, "popac", "Penumbra opacity", 25, (0, 100, 1)),
        (PF_SLIDER, "pthick", "Penumbra thickness", 50, (0, 100, 1)),
        (PF_INT, "upoffx", "Umbra/penumbra offset X", 5),
        (PF_INT, "upoffy", "Umbra/penumbra offset Y", 5),
        (PF_COLOR, "upcolor", "Umbra/penumbra color", (0,0,0)),
        (PF_INT, "vwidth", "Veil width", 500),
        (PF_SLIDER, "vopac", "Veil opacity", 25, (0, 100, 1)),
        (PF_SLIDER, "vthick", "Veil thickness", 25, (0, 100, 1)),
        (PF_COLOR, "vcolor", "Veil color", (0,0,0)),
        (PF_TOGGLE, "intogroup", "Move the source layer into the group", 0),
        (PF_TOGGLE, "flatten", "Flatten the group", 1)
    ],
    [],
    drop_shadow_advanced)

main()