plugins.partition — pyFormex 1.0.5 documentation

# Source code for plugins.partition

    # $Id$
    ##
    ##  This file is part of pyFormex 1.0.5  (Sat Feb 16 10:40:32 CET 2019)
    ##  pyFormex is a tool for generating, manipulating and transforming 3D
    ##  geometrical models by sequences of mathematical operations.
    ##  Home page: http://pyformex.org
    ##  Project page:  http://savannah.nongnu.org/projects/pyformex/
    ##  Copyright 2004-2018 (C) Benedict Verhegghe (benedict.verhegghe@ugent.be)
    ##  Distributed under the GNU General Public License version 3 or later.
    ##
    ##  This program is free software: you can redistribute it and/or modify
    ##  it under the terms of the GNU General Public License as published by
    ##  the Free Software Foundation, either version 3 of the License, or
    ##  (at your option) any later version.
    ##
    ##  This program is distributed in the hope that it will be useful,
    ##  but WITHOUT ANY WARRANTY; without even the implied warranty of
    ##  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ##  GNU General Public License for more details.
    ##
    ##  You should have received a copy of the GNU General Public License
    ##  along with this program.  If not, see http://www.gnu.org/licenses/.
    ##
    """Partitioning tools

    """
    from __future__ import absolute_import, division, print_function

    import pyformex as pf
    from pyformex.opengl import colors
    from pyformex.opengl import decors
    from pyformex.gui.draw import *
    from pyformex.formex import *
    from pyformex import geomtools

    import numpy
    inverse = numpy.linalg.linalg.inv

    VA=None

    def prepare(V):
        """Prepare the surface for slicing operation."""
        global VA
        V = V.translate(-V.center())
        P = V.center()
        print("Initial P = %s" % P)
        VA = draw(V, bbox=None, color='black')
        area, norm = geomtools.areaNormals(V.coords)
        N = norm[0]
        return V, P, N

    def testview(F, V, P):
        global VA, waiting
        p = array(pf.canvas.camera.focus)
        waiting = True
        while waiting:
            pf.app.processEvents()
        p -= array(pf.canvas.camera.focus)
        print("TRANSLATE: %s" % p)
        m = pf.canvas.camera.getRot()
        P += p
        print("TOTAL TRANSLATE: %s" % P)
        V = V.affine(inverse(m[0:3, 0:3])).translate(-P)
        print(V.center())
        print(F.center())
        undraw(VA)
        VA = draw(V)
        area, norm = geomtools.areaNormals(V.coords)
        N = norm[0]
        return P, N

    def colorCut(F, P, N, prop):
        """Color a Formex in two by a plane (P,N)"""
        print(F.bbox())
        print(P)
        print(N)
        print(prop)
        dist = F.distanceFromPlane(P, N)
        print(dist)
        right = any(dist>0.0, axis=1)
        print(right)
        F.prop[right] = prop
        nright = right.sum()
        nleft = F.nelems() - nright
        print("Left part has %s elements, right part has %s elements" % (nleft, nright))
        return F

    def splitProp(G, name):
        """Partition a Formex according to its prop values and export the results.

        If G has property numbers, the structure is split and according
        to the property values, and the (compacted) parts are exported
        with names 'name-propnumber'.
        """
        split = G.splitProp(compact=True)
        if split:
            names = [ '%s-%s' % (name, i) for i in unique(G.prop) ]
            export2(names,split)

    waiting = True

    def wakeup():
        global waiting
        waiting = False

    def partition(Fin,prop=0):
        """Interactively partition a Formex.

        By default, the parts will get properties 0,1,...
        If prop >= 0, the parts will get incremental props starting from prop.

        Returns the cutplanes in an array with shape (ncuts,2,3), where
          (i,0,:) is a point in the plane i and
          (i,1,:) is the normal vector on the plane i .

        As a side effect, the properties of the input Formex will be changed
        to flag the parts between successive cut planes by incrementing
        property values.
        If you wish to restore the original properties, you should copy them
        (or the input Formex) before calling this function.
        """
        global FA, VA, waiting

        # start color
        keepprops = prop
        if prop is None or prop < 0:
            prop = 0

        # Make sure the inital Formex is centered
        initial_trl = -Fin.center()
        F = Fin.translate(initial_trl)

        # Store the inital properties and make all properties equal to start value
        initial_prop = F.prop
        F.setProp(prop)

        # draw it
        linewidth(1)
        perspective(False)
        clear()
        FA = draw(F, view='front')

        # create a centered cross plane, large enough
        bb = F.bbox()
        siz = F.sizes().max()
        V = Formex([[[0., 0., 0.], [1., 0., 0.], [1., 1., 0.]],
                    [[1., 1., 0.], [0., 1., 0.], [0., 0., 0.]]],
                   0)
        V = V.translate(-V.center()).rotate(90, 1).scale(siz)

        cut_planes = []

        pf.GUI.signals.WAKEUP.connect(wakeup)

        linewidth(2)
        w, h = pf.canvas.width(), pf.canvas.height()
        fgcolor('magenta')
        SD = decors.Line(w/2, 0, w/2, h)
        decorate(SD)

        fgcolor(colors.black)

        V, P, N = prepare(V)
        while True:
            res = ask("", ["Adjust Cut", "Keep Cut", "Finish"])
            if res == "Adjust Cut":
                P, N = testview(F, V, P)
                print("Plane: point %s, normal %s" % (P, N))
            elif res == "Keep Cut":
                undraw(FA)
                #undraw(VA)
                cut_planes.append((P, N))
                prop += 1
                F = colorCut(F, -P, N, prop)
                FA = draw(F)
                undraw(VA)
                V, P, N = prepare(V)
            else:
                break

        pf.GUI.signals.WAKEUP.disconnect(wakeup)
        clear()
        draw(F)
        Fin.setProp(F.prop)
        return array(cut_planes)

    def savePartitions(F):
        print("Current dir is %s" % os.getcwd())
        if ack("Save the partitioned Formex?"):
            writeFormex(F, 'part.fmx')
            clear()

        if ack("Reread/draw the partitioned Formex?"):
            F = readFormex('part.fmx')
            draw(F)

        splitProp(F, 'part')

        if ack("Save the partitions separately?"):
            for (k, v) in d.items():
                writeFormex(v, "%s.fmx"%k)

    # End