213 lines
6.1 KiB
Python
213 lines
6.1 KiB
Python
# $Id$
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#
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# --------------------------------------------------------------------------
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# helper functions to be used by other scripts
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# --------------------------------------------------------------------------
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# ***** BEGIN GPL LICENSE BLOCK *****
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#
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# This program is free software; you can redistribute it and/or
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# modify it under the terms of the GNU General Public License
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# as published by the Free Software Foundation; either version 2
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# of the License, or (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software Foundation,
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# Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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#
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# ***** END GPL LICENCE BLOCK *****
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# --------------------------------------------------------------------------
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import Blender
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from Blender.Mathutils import *
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# ------ Mersenne Twister - start
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# Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura.
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# Any feedback is very welcome. For any question, comments,
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# see http://www.math.keio.ac.jp/matumoto/emt.html or email
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# matumoto@math.keio.ac.jp
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# The link above is dead, this is the new one:
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# http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/emt.html
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# And here the license info, from Mr. Matsumoto's site:
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# Until 2001/4/6, MT had been distributed under GNU Public License,
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# but after 2001/4/6, we decided to let MT be used for any purpose, including
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# commercial use. 2002-versions mt19937ar.c, mt19937ar-cok.c are considered
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# to be usable freely.
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#
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# So from the year above (1997), this code is under GPL.
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# Period parameters
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N = 624
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M = 397
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MATRIX_A = 0x9908b0dfL # constant vector a
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UPPER_MASK = 0x80000000L # most significant w-r bits
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LOWER_MASK = 0x7fffffffL # least significant r bits
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# Tempering parameters
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TEMPERING_MASK_B = 0x9d2c5680L
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TEMPERING_MASK_C = 0xefc60000L
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def TEMPERING_SHIFT_U(y):
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return (y >> 11)
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def TEMPERING_SHIFT_S(y):
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return (y << 7)
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def TEMPERING_SHIFT_T(y):
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return (y << 15)
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def TEMPERING_SHIFT_L(y):
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return (y >> 18)
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mt = [] # the array for the state vector
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mti = N+1 # mti==N+1 means mt[N] is not initialized
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# initializing the array with a NONZERO seed
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def sgenrand(seed):
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# setting initial seeds to mt[N] using
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# the generator Line 25 of Table 1 in
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# [KNUTH 1981, The Art of Computer Programming
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# Vol. 2 (2nd Ed.), pp102]
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global mt, mti
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mt = []
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mt.append(seed & 0xffffffffL)
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for i in xrange(1, N + 1):
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mt.append((69069 * mt[i-1]) & 0xffffffffL)
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mti = i
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# end sgenrand
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def genrand():
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global mt, mti
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mag01 = [0x0L, MATRIX_A]
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# mag01[x] = x * MATRIX_A for x=0,1
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y = 0
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if mti >= N: # generate N words at one time
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if mti == N+1: # if sgenrand() has not been called,
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sgenrand(4357) # a default initial seed is used
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for kk in xrange((N-M) + 1):
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y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK)
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mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1]
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for kk in xrange(kk, N):
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y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK)
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mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1]
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y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK)
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mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1]
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mti = 0
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y = mt[mti]
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mti += 1
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y ^= TEMPERING_SHIFT_U(y)
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y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B
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y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C
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y ^= TEMPERING_SHIFT_L(y)
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return ( float(y) / 0xffffffffL ) # reals
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#------ Mersenne Twister -- end
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""" 2d convexhull
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Based from Dinu C. Gherman's work,
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modified for Blender/Mathutils by Campell Barton
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"""
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######################################################################
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# Public interface
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######################################################################
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from Blender.Mathutils import DotVecs
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def convexHull(point_list_2d):
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"""Calculate the convex hull of a set of vectors
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The vectors can be 3 or 4d but only the Xand Y are used.
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returns a list of convex hull indicies to the given point list
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"""
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######################################################################
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# Helpers
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######################################################################
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def _myDet(p, q, r):
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"""Calc. determinant of a special matrix with three 2D points.
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The sign, "-" or "+", determines the side, right or left,
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respectivly, on which the point r lies, when measured against
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a directed vector from p to q.
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"""
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return (q.x*r.y + p.x*q.y + r.x*p.y) - (q.x*p.y + r.x*q.y + p.x*r.y)
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def _isRightTurn((p, q, r)):
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"Do the vectors pq:qr form a right turn, or not?"
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#assert p[0] != q[0] and q[0] != r[0] and p[0] != r[0]
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if _myDet(p[0], q[0], r[0]) < 0:
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return 1
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else:
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return 0
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# Get a local list copy of the points and sort them lexically.
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points = [(p, i) for i, p in enumerate(point_list_2d)]
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try: points.sort(key = lambda a: (a[0].x, a[0].y))
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except: points.sort(lambda a,b: cmp((a[0].x, a[0].y), (b[0].x, b[0].y)))
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# Build upper half of the hull.
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upper = [points[0], points[1]] # cant remove these.
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for i in xrange(len(points)-2):
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upper.append(points[i+2])
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while len(upper) > 2 and not _isRightTurn(upper[-3:]):
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del upper[-2]
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# Build lower half of the hull.
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points.reverse()
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lower = [points.pop(0), points.pop(1)]
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for p in points:
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lower.append(p)
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while len(lower) > 2 and not _isRightTurn(lower[-3:]):
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del lower[-2]
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# Concatenate both halfs and return.
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return [p[1] for ls in (upper, lower) for p in ls]
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def plane2mat(plane, normalize= False):
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'''
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Takes a plane and converts to a matrix
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points between 0 and 1 are up
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1 and 2 are right
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assumes the plane has 90d corners
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'''
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cent= (plane[0]+plane[1]+plane[2]+plane[3] ) /4.0
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up= cent - ((plane[0]+plane[1])/2.0)
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right= cent - ((plane[1]+plane[2])/2.0)
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z= CrossVecs(up, right)
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if normalize:
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up.normalize()
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right.normalize()
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z.normalize()
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mat= Matrix(up, right, z)
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# translate
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mat.resize4x4()
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tmat= Blender.Mathutils.TranslationMatrix(cent)
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return mat * tmat
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