pycad/py_src/Triangle.py


##############################################################################
#
# Copyright (c) 2003-2020 by The University of Queensland
# http://www.uq.edu.au
#
# Primary Business: Queensland, Australia
# Licensed under the Apache License, version 2.0
# http://www.apache.org/licenses/LICENSE-2.0
#
# Development until 2012 by Earth Systems Science Computational Center (ESSCC)
# Development 2012-2013 by School of Earth Sciences
# Development from 2014 by Centre for Geoscience Computing (GeoComp)
# Development from 2019 by School of Earth and Environmental Sciences
#
##############################################################################

from __future__ import print_function, division

__copyright__="""Copyright (c) 2003-2020 by The University of Queensland
http://www.uq.edu.au
Primary Business: Queensland, Australia"""
__license__="""Licensed under the Apache License, version 2.0
http://www.apache.org/licenses/LICENSE-2.0"""
__url__="https://launchpad.net/escript-finley"

"""
mesh generation using Triangle

:var __author__: name of author
:var __copyright__: copyrights
:var __license__: licence agreement
:var __url__: url entry point on documentation
:var __version__: version
:var __date__: date of the version
"""

__author__="Brett Tully, b.tully@uq.edu.au"

import tempfile
import os
import glob
import esys.pycad.design as design
import math 
from esys.pycad.primitives import Point, Spline, BezierCurve, BSpline, Line, Arc, CurveLoop, RuledSurface, PlaneSurface, SurfaceLoop, Volume, PropertySet
from esys.escript import getMPIWorldMax, getMPIRankWorld

class Design(design.AbstractDesign):
    """
    Design for Triangle.
    """
    def __init__(self,dim=2,keep_files=False):
       """
       Initializes the Triangle design.

       :param dim: spatial dimension
       :param keep_files: flag to keep work files
       """
       if dim != 2:
           raise ValueError("only dimension 2 is supported by Triangle.")
       design.AbstractDesign.__init__(self,dim=dim,keep_files=keep_files)
       self.__scriptname=""
       self.setScriptFileName()
       self.setMeshFileName()
       self.setOptions()

    def setScriptFileName(self,name=None):
       """
       Sets the filename for the Triangle input script. If no name is given
       a name with extension `poly` is generated.
       """
       if self.__scriptname:
           os.unlink(self.__scriptname)
       if name == None:
           self.__scriptname_set=False
           self.__scriptname=tempfile.mkstemp(suffix=".poly")[1]
       else:
           self.__scriptname_set=True
           self.__scriptname=name
           self.setMeshFileName(name)

    def getScriptFileName(self):
       """
       Returns the name of the gmsh script file.
       """
       return self.__scriptname

    def setMeshFileName(self,name=None):
       """
       Sets the name of the Triangle mesh file.
       """
       if self.__mshname:
           os.unlink(self.__mshname)
       if name == None:
           self.__mshname=tempfile.mkstemp(suffix="")[1]
       else:
           # Triangle creates a default filename so all we want to pass is
           # the basename
           if (".poly" in name) or (".ele" in name) or (".node" in name):
               s=name.split(".")[:-1]
               name=s[0]
               if len(s) > 1: name+=".%s"*(len(s)-1)%tuple(s[1:])
           self.__mshname=name
           self.setKeepFilesOn()

    def getMeshFileName(self):
       """
       Returns the name of the Triangle mesh file.
       """
       return self.__mshname

    def setOptions(self,cmdLineArgs=""):
        """
        Sets command line options for the mesh generator::

            triangle [-prq__a__uAcDjevngBPNEIOXzo_YS__iFlsCQVh] input_file

            see http://www.cs.cmu.edu/~quake/triangle.switch.html

        :param cmdLineArgs: the switches you would ordinarily use at the
                            command line (e.g. cmdLineArgs="pq25a7.5")
        """
        self.__cmdLineArgs=cmdLineArgs

    def __del__(self):
        """
        Cleans up.
        """
        if not self.keepFiles():
            if not self.__scriptname_set:
                os.unlink(self.getScriptFileName())
            if not self.__mshname_set:
                os.unlink(self.getMeshFileName())

    def getCommandString(self):
        """
        Returns the Triangle command line::

            triangle [-prq__a__uAcDjevngBPNEIOXzo_YS__iFlsCQVh] input_file

            see http://www.cs.cmu.edu/~quake/triangle.switch.html
        """
        if self.__cmdLineArgs == "":
            print("warning: using default command line arguments for Triangle")
        exe="triangle %s %%s"%self.__cmdLineArgs
        return exe

    def getMeshHandler(self):
        """
        Returns a handle to a mesh meshing the design. In the current
        implementation a mesh file name in Triangle format is returned.
        """
        args = self.getCommandString().split()
        args[-1]=args[-1]%self.getScriptFileName()
        if getMPIRankWorld() == 0:
            import subprocess
            open(self.getScriptFileName(),"w").write(self.getScriptString())
            ret = subprocess.call(args) / 256
        else:
            ret=0
        ret=getMPIWorldMax(ret)
        if ret > 0:
          raise RuntimeError("Could not build mesh: %s"%" ".join(args))
        else:
            # <hack> so that users can set the mesh filename they want.
            name=self.getScriptFileName()
            if (".poly" in name) or (".ele" in name) or (".node" in name):
                s=name.split(".")[:-1]
                name=s[0]
                if len(s) > 1: name+=".%s"*(len(s)-1)%tuple(s[1:])
            files=glob.glob("%s.1.*"%name)
            for f in files:
                sufx=f.split(".")[-1]
                mshName=self.getMeshFileName()+"."+sufx
                os.rename(f,mshName)
            # </hack>
            return self.getMeshFileName()

    def getScriptString(self):
        """
        Returns the Triangle script to generate the mesh.
        """
        # comment lines are prefixed by a '#' in triangle *.poly files
        out="# generated by esys.pycad\n"
        vertices="";vertCnt=0
        segments="";segCnt=0
        holestr="";holeCnt=0
        ctrlPts={}
        for prim in self.getItems():

            p=prim.getUnderlyingPrimitive()

            if isinstance(p, PropertySet):
               PSprims=p.getItems()
               for PSp in PSprims:
                   if isinstance(PSp, Point):
                       c=PSp.getCoordinates()
                       vertCnt+=1
                       vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())

                   elif isinstance(PSp, Line):
                       # get end points and add them as vertices
                       # add line segments - bnd_mkr's are p.getID()
                       # and p.getID() should be mapped to the FID's from the GIS
                       pts=list(PSp.getControlPoints())
                       for pt in pts:
                           c=pt.getCoordinates()
                           if pt not in list(ctrlPts.keys()):
                               vertCnt+=1
                               vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())
                               ctrlPts[pt]=vertCnt
                           ptIndx=pts.index(pt)
                           if ptIndx != 0:
                               segCnt+=1
                               segments+="%s %s %s %s\n"%(segCnt,
                                                          ctrlPts[pts[ptIndx-1]],
                                                          ctrlPts[pts[ptIndx]],
                                                          p.getID())

                   elif isinstance(PSp, Spline) or isinstance(PSp, BezierCurve) or \
                        isinstance(PSp, BSpline) or isinstance(PSp, Arc):
                       TypeError("Triangle can only handle linear curves: not %s objects."%str(type(p)))

                   elif isinstance(PSp, PlaneSurface):

                       outerBnd=PSp.getBoundaryLoop()
                       holes=PSp.getHoles()

                       for curve in outerBnd.getCurves():
                           pts=list(curve.getControlPoints())
                           for pt in pts:
                               c=pt.getCoordinates()
                               if pt not in list(ctrlPts.keys()):
                                   vertCnt+=1
                                   vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())
                                   ctrlPts[pt]=vertCnt
                               ptIndx=pts.index(pt)
                               if ptIndx != 0:
                                   segCnt+=1
                                   segments+="%s %s %s %s\n"%(segCnt,
                                                              ctrlPts[pts[ptIndx-1]],
                                                              ctrlPts[pts[ptIndx]],
                                                              p.getID())
# in order to deal with holes in Triangle, you must place a hole node inside
# the boundary of the polygon that describes the hole. For a convex polygon
# (all internal angles < 180 degrees) this is easy, however, for concave
# polygons (one or more internal angles > 180 degrees) this is much
# more difficult. Easiest method is to find the smallest internal angle, and
# place the hole node inside the triangle formed by the three vertices
# associated with that internal angle.
                       for hole in holes:
                           holePts=[]
                           for curve in hole.getCurves():
                               pts=list(curve.getControlPoints())
                               for pt in pts:
                                   c=pt.getCoordinates()
                                   if pt not in list(ctrlPts.keys()):
                                       vertCnt+=1
                                       vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())
                                       ctrlPts[pt]=vertCnt
                                   ptIndx=pts.index(pt)
                                   if ptIndx != 0:
                                       segCnt+=1
                                       segments+="%s %s %s %s\n"%(segCnt,
                                                                  ctrlPts[pts[ptIndx-1]],
                                                                  ctrlPts[pts[ptIndx]],
                                                                  p.getID())
                                   if pt not in holePts:
                                       holePts.append(pt)
                           vectors=[] # the key corresponds to the ctrlPts index
                           # create vectors
                           for i in range(len(holePts)):
                               A=holePts[i]
                               vectors.append([])
                               if i == 0:
                                   B=holePts[1]
                                   C=holePts[-1]
                               elif i == len(holePts)-1:
                                   B=holePts[0]
                                   C=holePts[-2]
                               else:
                                   B=holePts[i+1]
                                   C=holePts[i-1]
                               vectors[i].append(self.__getVector(A,B))
                               vectors[i].append(self.__getVector(A,C))
                           # get angle between vectors at each vertex
                           for i in range(len(vectors)):
                               angle=self.__getAngle(vectors[i][0],vectors[i][1])
                               vectors[i].append(angle)
                           # find the vertex with the smallest angle
                           minAngle=360.
                           indx=0
                           for i in range(len(vectors)):
                               if vectors[i][2] < minAngle:
                                   indx=i
                                   minAngle=vectors[i][2]
                           # find a node inside the triangle stemming from the
                           # vertex with the smallest internal angle. Do this by
                           # adding 5% of each of the vectorsesys.pycad. to the current point
                           A=holePts[indx]
                           cA=A.getCoordinates()
                           x=cA[0]+(vectors[indx][0][0]+vectors[indx][1][0])/20.
                           y=cA[1]+(vectors[indx][0][1]+vectors[indx][1][1])/20.
                           # use this node to define the hole.
                           holeCnt+=1
                           holestr+="%s %s %s\n"%(holeCnt,x,y)

                   else:
                       raise TypeError("please pass correct PropertySet objects to Triangle design")
            else:
                raise TypeError("please pass only PropertySet objects to Triangle design")
        out+="# vertices #\n"
        out+="%i 2 0 1\n"%(vertCnt)
        out+=vertices
        out+="# segments #\n"
        out+="%i 1\n"%(segCnt)
        out+=segments
        out+="# holes #\n"
        out+="%i\n"%(holeCnt)
        out+=holestr
        return out

    def __getVector(self,A,B):
        # get the vector between two points.
        cA=A.getCoordinates()
        cB=B.getCoordinates()
        x=cB[0]-cA[0]
        y=cB[1]-cA[1]
        return [x,y]

    def __getAngle(self,v,w):
        # get internal (directional) angle between two vectors (in degrees).
        theta=atan2(v[1],v[0]) - atan2(w[1],w[0])
        theta=theta*180./pi
        if theta < 0.:
            theta+=360.
        return theta

1
2	##############################################################################
3	#
4	# Copyright (c) 2003-2020 by The University of Queensland
5	# http://www.uq.edu.au
6	#
7	# Primary Business: Queensland, Australia
8	# Licensed under the Apache License, version 2.0
9	# http://www.apache.org/licenses/LICENSE-2.0
10	#
11	# Development until 2012 by Earth Systems Science Computational Center (ESSCC)
12	# Development 2012-2013 by School of Earth Sciences
13	# Development from 2014 by Centre for Geoscience Computing (GeoComp)
14	# Development from 2019 by School of Earth and Environmental Sciences
15	#
16	##############################################################################
17
18	from __future__ import print_function, division
19
20	__copyright__="""Copyright (c) 2003-2020 by The University of Queensland
21	http://www.uq.edu.au
22	Primary Business: Queensland, Australia"""
23	__license__="""Licensed under the Apache License, version 2.0
24	http://www.apache.org/licenses/LICENSE-2.0"""
25	__url__="https://launchpad.net/escript-finley"
26
27	"""
28	mesh generation using Triangle
29
30	:var __author__: name of author
31	:var __copyright__: copyrights
32	:var __license__: licence agreement
33	:var __url__: url entry point on documentation
34	:var __version__: version
35	:var __date__: date of the version
36	"""
37
38	__author__="Brett Tully, b.tully@uq.edu.au"
39
40	import tempfile
41	import os
42	import glob
43	import esys.pycad.design as design
44	import math
45	from esys.pycad.primitives import Point, Spline, BezierCurve, BSpline, Line, Arc, CurveLoop, RuledSurface, PlaneSurface, SurfaceLoop, Volume, PropertySet
46	from esys.escript import getMPIWorldMax, getMPIRankWorld
47
48	class Design(design.AbstractDesign):
49	"""
50	Design for Triangle.
51	"""
52	def __init__(self,dim=2,keep_files=False):
53	"""
54	Initializes the Triangle design.
55
56	:param dim: spatial dimension
57	:param keep_files: flag to keep work files
58	"""
59	if dim != 2:
60	raise ValueError("only dimension 2 is supported by Triangle.")
61	design.AbstractDesign.__init__(self,dim=dim,keep_files=keep_files)
62	self.__scriptname=""
63	self.setScriptFileName()
64	self.setMeshFileName()
65	self.setOptions()
66
67	def setScriptFileName(self,name=None):
68	"""
69	Sets the filename for the Triangle input script. If no name is given
70	a name with extension `poly` is generated.
71	"""
72	if self.__scriptname:
73	os.unlink(self.__scriptname)
74	if name == None:
75	self.__scriptname_set=False
76	self.__scriptname=tempfile.mkstemp(suffix=".poly")[1]
77	else:
78	self.__scriptname_set=True
79	self.__scriptname=name
80	self.setMeshFileName(name)
81
82	def getScriptFileName(self):
83	"""
84	Returns the name of the gmsh script file.
85	"""
86	return self.__scriptname
87
88	def setMeshFileName(self,name=None):
89	"""
90	Sets the name of the Triangle mesh file.
91	"""
92	if self.__mshname:
93	os.unlink(self.__mshname)
94	if name == None:
95	self.__mshname=tempfile.mkstemp(suffix="")[1]
96	else:
97	# Triangle creates a default filename so all we want to pass is
98	# the basename
99	if (".poly" in name) or (".ele" in name) or (".node" in name):
100	s=name.split(".")[:-1]
101	name=s[0]
102	if len(s) > 1: name+=".%s"*(len(s)-1)%tuple(s[1:])
103	self.__mshname=name
104	self.setKeepFilesOn()
105
106	def getMeshFileName(self):
107	"""
108	Returns the name of the Triangle mesh file.
109	"""
110	return self.__mshname
111
112	def setOptions(self,cmdLineArgs=""):
113	"""
114	Sets command line options for the mesh generator::
115
116	triangle [-prq__a__uAcDjevngBPNEIOXzo_YS__iFlsCQVh] input_file
117
118	see http://www.cs.cmu.edu/~quake/triangle.switch.html
119
120	:param cmdLineArgs: the switches you would ordinarily use at the
121	command line (e.g. cmdLineArgs="pq25a7.5")
122	"""
123	self.__cmdLineArgs=cmdLineArgs
124
125	def __del__(self):
126	"""
127	Cleans up.
128	"""
129	if not self.keepFiles():
130	if not self.__scriptname_set:
131	os.unlink(self.getScriptFileName())
132	if not self.__mshname_set:
133	os.unlink(self.getMeshFileName())
134
135	def getCommandString(self):
136	"""
137	Returns the Triangle command line::
138
139	triangle [-prq__a__uAcDjevngBPNEIOXzo_YS__iFlsCQVh] input_file
140
141	see http://www.cs.cmu.edu/~quake/triangle.switch.html
142	"""
143	if self.__cmdLineArgs == "":
144	print("warning: using default command line arguments for Triangle")
145	exe="triangle %s %%s"%self.__cmdLineArgs
146	return exe
147
148	def getMeshHandler(self):
149	"""
150	Returns a handle to a mesh meshing the design. In the current
151	implementation a mesh file name in Triangle format is returned.
152	"""
153	args = self.getCommandString().split()
154	args[-1]=args[-1]%self.getScriptFileName()
155	if getMPIRankWorld() == 0:
156	import subprocess
157	open(self.getScriptFileName(),"w").write(self.getScriptString())
158	ret = subprocess.call(args) / 256
159	else:
160	ret=0
161	ret=getMPIWorldMax(ret)
162	if ret > 0:
163	raise RuntimeError("Could not build mesh: %s"%" ".join(args))
164	else:
165	# <hack> so that users can set the mesh filename they want.
166	name=self.getScriptFileName()
167	if (".poly" in name) or (".ele" in name) or (".node" in name):
168	s=name.split(".")[:-1]
169	name=s[0]
170	if len(s) > 1: name+=".%s"*(len(s)-1)%tuple(s[1:])
171	files=glob.glob("%s.1.*"%name)
172	for f in files:
173	sufx=f.split(".")[-1]
174	mshName=self.getMeshFileName()+"."+sufx
175	os.rename(f,mshName)
176	# </hack>
177	return self.getMeshFileName()
178
179	def getScriptString(self):
180	"""
181	Returns the Triangle script to generate the mesh.
182	"""
183	# comment lines are prefixed by a '#' in triangle *.poly files
184	out="# generated by esys.pycad\n"
185	vertices="";vertCnt=0
186	segments="";segCnt=0
187	holestr="";holeCnt=0
188	ctrlPts={}
189	for prim in self.getItems():
190
191	p=prim.getUnderlyingPrimitive()
192
193	if isinstance(p, PropertySet):
194	PSprims=p.getItems()
195	for PSp in PSprims:
196	if isinstance(PSp, Point):
197	c=PSp.getCoordinates()
198	vertCnt+=1
199	vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())
200
201	elif isinstance(PSp, Line):
202	# get end points and add them as vertices
203	# add line segments - bnd_mkr's are p.getID()
204	# and p.getID() should be mapped to the FID's from the GIS
205	pts=list(PSp.getControlPoints())
206	for pt in pts:
207	c=pt.getCoordinates()
208	if pt not in list(ctrlPts.keys()):
209	vertCnt+=1
210	vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())
211	ctrlPts[pt]=vertCnt
212	ptIndx=pts.index(pt)
213	if ptIndx != 0:
214	segCnt+=1
215	segments+="%s %s %s %s\n"%(segCnt,
216	ctrlPts[pts[ptIndx-1]],
217	ctrlPts[pts[ptIndx]],
218	p.getID())
219
220	elif isinstance(PSp, Spline) or isinstance(PSp, BezierCurve) or \
221	isinstance(PSp, BSpline) or isinstance(PSp, Arc):
222	TypeError("Triangle can only handle linear curves: not %s objects."%str(type(p)))
223
224	elif isinstance(PSp, PlaneSurface):
225
226	outerBnd=PSp.getBoundaryLoop()
227	holes=PSp.getHoles()
228
229	for curve in outerBnd.getCurves():
230	pts=list(curve.getControlPoints())
231	for pt in pts:
232	c=pt.getCoordinates()
233	if pt not in list(ctrlPts.keys()):
234	vertCnt+=1
235	vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())
236	ctrlPts[pt]=vertCnt
237	ptIndx=pts.index(pt)
238	if ptIndx != 0:
239	segCnt+=1
240	segments+="%s %s %s %s\n"%(segCnt,
241	ctrlPts[pts[ptIndx-1]],
242	ctrlPts[pts[ptIndx]],
243	p.getID())
244	# in order to deal with holes in Triangle, you must place a hole node inside
245	# the boundary of the polygon that describes the hole. For a convex polygon
246	# (all internal angles < 180 degrees) this is easy, however, for concave
247	# polygons (one or more internal angles > 180 degrees) this is much
248	# more difficult. Easiest method is to find the smallest internal angle, and
249	# place the hole node inside the triangle formed by the three vertices
250	# associated with that internal angle.
251	for hole in holes:
252	holePts=[]
253	for curve in hole.getCurves():
254	pts=list(curve.getControlPoints())
255	for pt in pts:
256	c=pt.getCoordinates()
257	if pt not in list(ctrlPts.keys()):
258	vertCnt+=1
259	vertices+="%s %s %s %s\n"%(vertCnt,c[0],c[1],p.getID())
260	ctrlPts[pt]=vertCnt
261	ptIndx=pts.index(pt)
262	if ptIndx != 0:
263	segCnt+=1
264	segments+="%s %s %s %s\n"%(segCnt,
265	ctrlPts[pts[ptIndx-1]],
266	ctrlPts[pts[ptIndx]],
267	p.getID())
268	if pt not in holePts:
269	holePts.append(pt)
270	vectors=[] # the key corresponds to the ctrlPts index
271	# create vectors
272	for i in range(len(holePts)):
273	A=holePts[i]
274	vectors.append([])
275	if i == 0:
276	B=holePts[1]
277	C=holePts[-1]
278	elif i == len(holePts)-1:
279	B=holePts[0]
280	C=holePts[-2]
281	else:
282	B=holePts[i+1]
283	C=holePts[i-1]
284	vectors[i].append(self.__getVector(A,B))
285	vectors[i].append(self.__getVector(A,C))
286	# get angle between vectors at each vertex
287	for i in range(len(vectors)):
288	angle=self.__getAngle(vectors[i][0],vectors[i][1])
289	vectors[i].append(angle)
290	# find the vertex with the smallest angle
291	minAngle=360.
292	indx=0
293	for i in range(len(vectors)):
294	if vectors[i][2] < minAngle:
295	indx=i
296	minAngle=vectors[i][2]
297	# find a node inside the triangle stemming from the
298	# vertex with the smallest internal angle. Do this by
299	# adding 5% of each of the vectorsesys.pycad. to the current point
300	A=holePts[indx]
301	cA=A.getCoordinates()
302	x=cA[0]+(vectors[indx][0][0]+vectors[indx][1][0])/20.
303	y=cA[1]+(vectors[indx][0][1]+vectors[indx][1][1])/20.
304	# use this node to define the hole.
305	holeCnt+=1
306	holestr+="%s %s %s\n"%(holeCnt,x,y)
307
308	else:
309	raise TypeError("please pass correct PropertySet objects to Triangle design")
310	else:
311	raise TypeError("please pass only PropertySet objects to Triangle design")
312	out+="# vertices #\n"
313	out+="%i 2 0 1\n"%(vertCnt)
314	out+=vertices
315	out+="# segments #\n"
316	out+="%i 1\n"%(segCnt)
317	out+=segments
318	out+="# holes #\n"
319	out+="%i\n"%(holeCnt)
320	out+=holestr
321	return out
322
323	def __getVector(self,A,B):
324	# get the vector between two points.
325	cA=A.getCoordinates()
326	cB=B.getCoordinates()
327	x=cB[0]-cA[0]
328	y=cB[1]-cA[1]
329	return [x,y]
330
331	def __getAngle(self,v,w):
332	# get internal (directional) angle between two vectors (in degrees).
333	theta=atan2(v[1],v[0]) - atan2(w[1],w[0])
334	theta=theta*180./pi
335	if theta < 0.:
336	theta+=360.
337	return theta
338