# SPDX-FileCopyrightText: 2008-2023 Blender Authors
#
# SPDX-License-Identifier: GPL-2.0-or-later

#  Author   : Stephane Grabli
#  Date     : 04/08/2005
#  Purpose  : Selects the lines that are long and have a high anisotropic
#             a priori density and uses causal density
#             to draw without cluttering. Ideally, half of the
#             selected lines are culled using the causal density.
#
#             ********************* WARNING *************************************
#             ******** The Directional a priori density maps must          ******
#             ******** have been computed prior to using this style module ******

from freestyle.chainingiterators import ChainSilhouetteIterator
from freestyle.functions import DensityF1D
from freestyle.predicates import (
    NotUP1D,
    QuantitativeInvisibilityUP1D,
    UnaryPredicate1D,
    pyHighDensityAnisotropyUP1D,
    pyHigherLengthUP1D,
    pyLengthBP1D,
)
from freestyle.shaders import (
    ConstantColorShader,
    ConstantThicknessShader,
    SamplingShader,
)
from freestyle.types import IntegrationType, Operators


# custom density predicate
class pyDensityUP1D(UnaryPredicate1D):
    def __init__(self, wsize, threshold, integration=IntegrationType.MEAN, sampling=2.0):
        UnaryPredicate1D.__init__(self)
        self._wsize = wsize
        self._threshold = threshold
        self._integration = integration
        self._func = DensityF1D(self._wsize, self._integration, sampling)
        self._func2 = DensityF1D(self._wsize, IntegrationType.MAX, sampling)

    def __call__(self, inter):
        c = self._func(inter)
        m = self._func2(inter)
        if c < self._threshold:
            return 1
        if m > 4 * c:
            if c < 1.5 * self._threshold:
                return 1
        return 0


Operators.select(QuantitativeInvisibilityUP1D(0))
Operators.bidirectional_chain(ChainSilhouetteIterator(), NotUP1D(QuantitativeInvisibilityUP1D(0)))
Operators.select(pyHigherLengthUP1D(40))
# selects lines having a high anisotropic a priori density
Operators.select(pyHighDensityAnisotropyUP1D(0.3, 4))
Operators.sort(pyLengthBP1D())
shaders_list = [
    SamplingShader(2.0),
    ConstantThicknessShader(2),
    ConstantColorShader(0.2, 0.2, 0.25, 1),
]
# uniform culling
Operators.create(pyDensityUP1D(3.0, 2.0e-2, IntegrationType.MEAN, 0.1), shaders_list)
