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mightyscape-1.1-deprecated/extensions/fablabchemnitz/shape_recognition/shaperrec/internal.py

351 lines
12 KiB
Python

import numpy
import sys
from shaperrec import geometric
from shaperrec import miscellaneous
# *************************************************************
# debugging
def void(*l):
pass
def debug_on(*l):
sys.stderr.write(' '.join(str(i) for i in l) +'\n')
debug = void
#debug = debug_on
# *************************************************************
# Internal Objects
class Path(object):
"""Private representation of a sequence of points.
A SVG node of type 'path' is splitted in several of these Path objects.
"""
next = None # next Path in the sequence of path corresponding to a SVG node
prev = None # previous Path in the sequence of path corresponding to a SVG node
sourcepoints = None # the full list of points from which this path is a subset
normalv = None # normal vector to this Path
def __init__(self, points):
"""points an array of points """
self.points = points
self.init()
def init(self):
self.effectiveNPoints = len(self.points)
if self.effectiveNPoints>1:
self.length, self.univ = geometric.dirAndLength(self.points[0], self.points[-1])
else:
self.length, self.univ = 0, numpy.array([0, 0])
if self.effectiveNPoints>0:
self.pointN=self.points[-1]
self.point1=self.points[0]
def isSegment(self):
return False
def quality(self):
return 1000
def dump(self):
n = len(self.points)
if n>0:
return 'path at '+str(self.points[0])+ ' to '+ str(self.points[-1])+' npoints=%d / %d (eff)'%(n, self.effectiveNPoints)
else:
return 'path Void !'
def setNewLength(self, l):
self.newLength = l
def removeLastPoints(self, n):
self.points = self.points[:-n]
self.init()
def removeFirstPoints(self, n):
self.points = self.points[n:]
self.init()
def costheta(self, seg):
return self.unitv.dot(seg.unitv)
def translate(self, tr):
"""Translate this path by tr"""
self.points = self.points + tr
def asSVGCommand(self, firstP=False):
svgCommands = []
com = 'M' if firstP else 'L'
for p in self.points:
svgCommands.append( [com, [p[0], p[1]] ] )
com='L'
return svgCommands
def setIntersectWithNext(self, next=None):
pass
def mergedWithNext(self, newPath=None):
""" Returns the combination of self and self.next.
sourcepoints has to be set
"""
if newPath is None: newPath = Path( numpy.concatenate([self.points, self.next.points]) )
newPath.sourcepoints = self.sourcepoints
newPath.prev = self.prev
if self.prev : newPath.prev.next = newPath
newPath.next = self.next.__next__
if newPath.__next__:
newPath.next.prev = newPath
return newPath
# *************************************************************
#
class Segment(Path):
""" A segment. Defined by its line equation ax+by+c=0 and the points from orignal paths
it is ensured that a**2+b**2 = 1
"""
QUALITYCUT = 0.9
newAngle = None # temporary angle set during the "parralelization" step
newLength = None # temporary lenght set during the "parralelization" step
# Segment Builders
@staticmethod
def from2Points( p1, p2, refPoints = None):
dirV = p2-p1
center = 0.5*(p2+p1)
return Segment.fromCenterAndDir(center, dirV, refPoints)
@staticmethod
def fromCenterAndDir( center, dirV, refPoints=None):
b = dirV[0]
a = -dirV[1]
c = - (a*center[0]+b*center[1])
if refPoints is None:
refPoints = numpy.array([ center-0.5*dirV, center+0.5*dirV] )
s = Segment( a, b, c, refPoints)
return s
def __init__(self, a,b,c, points, doinit=True):
"""a,b,c: the line parameters.
points : the array of 2D points represented by this Segment
doinit : if true will compute additionnal parameters to this Segment (first/last points, unit vector,...)
"""
self.a = a
self.b = b
self.c = c
self.points = points
d = numpy.sqrt(a**2+b**2)
if d != 1. :
self.a /= d
self.b /= d
self.c /= d
if doinit :
self.init()
def init(self):
a, b, c = self.a, self.b, self.c
x, y = self.points[0]
self.point1 = numpy.array( [ b*(x*b-y*a) - c*a, a*(y*a-x*b) - c*b ] )
x, y = self.points[-1]
self.pointN = numpy.array( [ b*(x*b-y*a) - c*a, a*(y*a-x*b) - c*b ] )
uv = self.computeDirLength()
self.distancesToLine = self.computeDistancesToLine(self.points)
self.normalv = numpy.array( [ a, b ])
self.angle = numpy.arccos( uv[0] )*numpy.sign(uv[1] )
def computeDirLength(self):
"""re-compute and set unit vector and length """
self.length, uv = geometric.dirAndLength(self.pointN, self.point1)
self.unitv = uv
return uv
def isSegment(self):
return True
def recomputeEndPoints(self):
a, b, c = self.a, self.b, self.c
x, y = self.points[0]
self.point1 = numpy.array( [ b*(x*b-y*a) - c*a, a*(y*a-x*b) - c*b ] )
x, y = self.points[-1]
self.pointN = numpy.array( [ b*(x*b-y*a) - c*a, a*(y*a-x*b) - c*b ] )
self.length = numpy.sqrt( geometric.D2(self.pointN, self.point1) )
def projectPoint(self, p):
""" return the point projection of p onto this segment"""
a, b, c = self.a, self.b, self.c
x, y = p
return numpy.array( [ b*(x*b-y*a) - c*a, a*(y*a-x*b) - c*b ] )
def intersect(self, seg):
"""Returns the intersection of this line with the line seg"""
nu, nv = self.normalv, seg.normalv
u = numpy.array([[-self.c], [-seg.c]])
doRotation = min(nu.min(), nv.min()) <1e-4
if doRotation:
# rotate to avoid numerical issues
nu = numpy.array(geometric.rotMat.dot(nu))[0]
nv = numpy.array(geometric.rotMat.dot(nv))[0]
m = numpy.matrix( (nu, nv) )
i = (m**-1).dot(u)
i=numpy.array( i).swapaxes(0, 1)[0]
debug(' intersection ', nu, nv, self.angle, seg.angle, ' --> ', i)
if doRotation:
i = geometric.unrotMat.dot(i).A1
debug(' ', i)
return i
def setIntersectWithNext(self, next=None):
"""Modify self such as self.pointN is the intersection with next segment """
if next is None:
next = self.__next__
if next and next.isSegment():
if abs(self.normalv.dot(next.unitv)) < 1e-3:
return
debug(' Intersect', self, next, ' from ', self.point1, self.pointN, ' to ', next.point1, next.pointN,)
inter = self.intersect(next)
debug(' --> ', inter, ' d=', geometric.D(self.pointN, inter) )
next.point1 = inter
self.pointN = inter
self.computeDirLength()
next.computeDirLength()
def computeDistancesToLine(self, points):
"""points: array of points.
returns the array of distances to this segment"""
return abs(self.a*points[:, 0]+self.b*points[:, 1]+self.c)
def distanceTo(self, point):
return abs(self.a*point[0]+self.b*point[1]+self.c)
def inverse(self):
"""swap all x and y values. """
def inv(v):
v[0], v[1] = v[1], v[0]
for v in [self.point1, self.pointN, self.unitv, self.normalv]:
inv(v)
self.points = numpy.roll(self.points, 1, axis=1)
self.a, self.b = self.b, self.a
self.angle = numpy.arccos( self.unitv[0] )*numpy.sign(self.unitv[1] )
return
def dumpShort(self):
return 'seg '+' '+str(self.point1 )+'to '+str(self.pointN)+ ' npoints=%d | angle,offset=(%.2f,%.2f )'%(len(self.points), self.angle, self.c)+' ', self.normalv
def dump(self):
v = self.variance()
n = len(self.points)
return 'seg '+str(self.point1 )+' , '+str(self.pointN)+ ' v/l=%.2f / %.2f = %.2f r*numpy.sqrt(n)=%.2f npoints=%d | angle,offset=(%.2f,%.2f )'%(v, self.length, v/self.length, v/self.length*numpy.sqrt(n), n, self.angle, self.c)
def variance(self):
d = self.distancesToLine
return numpy.sqrt( (d**2).sum()/len(d) )
def quality(self):
n = len(self.points)
return min(self.variance()/self.length*numpy.sqrt(n), 1000)
def formatedSegment(self, firstP=False):
return self.asSVGCommand(firstP)
def asSVGCommand(self, firstP=False):
if firstP:
segment = [ ['M', [self.point1[0], self.point1[1] ] ],
['L', [self.pointN[0], self.pointN[1] ] ]
]
else:
segment = [ ['L', [self.pointN[0], self.pointN[1] ] ] ]
#debug("Segment, format : ", segment)
return segment
def replaceInList(self, startPos, fullList):
code0 = fullList[startPos][0]
segment = [ [code0, [self.point1[0], self.point1[1] ] ],
['L', [self.pointN[0], self.pointN[1] ] ]
]
l = fullList[:startPos]+segment+fullList[startPos+len(self.points):]
return l
def mergedWithNext(self, doRefit=True):
""" Returns the combination of self and self.next.
sourcepoints has to be set
"""
spoints = numpy.concatenate([self.points, self.next.points])
if doRefit:
newSeg = fitSingleSegment(spoints)
else:
newSeg = Segment.fromCenterAndDir(geometric.barycenter(spoints), self.unitv, spoints)
newSeg = Path.mergedWithNext(self, newSeg)
return newSeg
def center(self):
return 0.5*(self.point1+self.pointN)
def box(self):
return geometric.computeBox(self.points)
def translate(self, tr):
"""Translate this segment by tr """
c = self.c -self.a*tr[0] -self.b*tr[1]
self.c =c
self.pointN = self.pointN+tr
self.point1 = self.point1+tr
self.points +=tr
def adjustToNewAngle(self):
"""reset all parameters so that self.angle is change to self.newAngle """
self.a, self.b, self.c = miscellaneous.parametersFromPointAngle( 0.5*(self.point1+self.pointN), self.newAngle)
#print 'adjustToNewAngle ', self, self.angle, self.newAngle
self.angle = self.newAngle
self.normalv = numpy.array( [ self.a, self.b ])
self.unitv = numpy.array( [ self.b, -self.a ])
if abs(self.angle) > numpy.pi/2 :
if self.b > 0: self.unitv *= -1
elif self.b<0 : self.unitv *= -1
self.point1 = self.projectPoint(self.point1) # reset point1
if not hasattr(self, "__next__") or not self.next.isSegment():
# move the last point (no intersect with next)
pN = self.projectPoint(self.pointN)
dirN = pN - self.point1
lN = geometric.length(pN, self.point1)
self.pointN = dirN/lN*self.length + self.point1
#print ' ... adjusting last seg angle ',p.dump() , ' normalv=', p.normalv, 'unitv ', p.unitv
else:
self.setIntersectWithNext()
def adjustToNewDistance(self):
self.pointN = self.newLength* self.unitv + self.point1
self.length = self.newLength
def tempLength(self):
if self.newLength : return self.newLength
else : return self.length
def tempAngle(self):
if self.newAngle: return self.newAngle
return self.angle