# SPDX-License-Identifier: GPL-2.0-or-later

#  Filename : external_contour_smooth.py
#  Author   : Stephane Grabli
#  Date     : 04/08/2005
#  Purpose  : Draws a smooth external contour

from freestyle.chainingiterators import ChainPredicateIterator
from freestyle.predicates import (
    AndUP1D,
    ExternalContourUP1D,
    NotUP1D,
    QuantitativeInvisibilityUP1D,
    TrueBP1D,
    TrueUP1D,
)
from freestyle.shaders import (
    IncreasingColorShader,
    IncreasingThicknessShader,
    SamplingShader,
    SmoothingShader,
)
from freestyle.types import Operators


upred = AndUP1D(QuantitativeInvisibilityUP1D(0), ExternalContourUP1D())
Operators.select(upred)
bpred = TrueBP1D()
Operators.bidirectional_chain(ChainPredicateIterator(upred, bpred), NotUP1D(upred))
shaders_list = [
    SamplingShader(2),
    IncreasingThicknessShader(4, 20),
    IncreasingColorShader(1.0, 0.0, 0.5, 1, 0.5, 1, 0.3, 1),
    SmoothingShader(100, 0.05, 0, 0.2, 0, 0, 0, 1),
]
Operators.create(TrueUP1D(), shaders_list)