blender/release/scripts/bpymodules/BPyMathutils.py

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# $Id$
#
# --------------------------------------------------------------------------
# helper functions to be used by other scripts
# --------------------------------------------------------------------------
# ***** BEGIN GPL LICENSE BLOCK *****
#
# 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 2
# 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, write to the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#
# ***** END GPL LICENCE BLOCK *****
# --------------------------------------------------------------------------
import Blender
from Blender.Mathutils import *
# ------ Mersenne Twister - start
# Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura.
# Any feedback is very welcome. For any question, comments,
# see http://www.math.keio.ac.jp/matumoto/emt.html or email
# matumoto@math.keio.ac.jp
# The link above is dead, this is the new one:
# http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/emt.html
# And here the license info, from Mr. Matsumoto's site:
# Until 2001/4/6, MT had been distributed under GNU Public License,
# but after 2001/4/6, we decided to let MT be used for any purpose, including
# commercial use. 2002-versions mt19937ar.c, mt19937ar-cok.c are considered
# to be usable freely.
#
# So from the year above (1997), this code is under GPL.
# Period parameters
N = 624
M = 397
MATRIX_A = 0x9908b0dfL # constant vector a
UPPER_MASK = 0x80000000L # most significant w-r bits
LOWER_MASK = 0x7fffffffL # least significant r bits
# Tempering parameters
TEMPERING_MASK_B = 0x9d2c5680L
TEMPERING_MASK_C = 0xefc60000L
def TEMPERING_SHIFT_U(y):
return (y >> 11)
def TEMPERING_SHIFT_S(y):
return (y << 7)
def TEMPERING_SHIFT_T(y):
return (y << 15)
def TEMPERING_SHIFT_L(y):
return (y >> 18)
mt = [] # the array for the state vector
mti = N+1 # mti==N+1 means mt[N] is not initialized
# initializing the array with a NONZERO seed
def sgenrand(seed):
# setting initial seeds to mt[N] using
# the generator Line 25 of Table 1 in
# [KNUTH 1981, The Art of Computer Programming
# Vol. 2 (2nd Ed.), pp102]
global mt, mti
mt = []
mt.append(seed & 0xffffffffL)
for i in xrange(1, N + 1):
mt.append((69069 * mt[i-1]) & 0xffffffffL)
mti = i
# end sgenrand
def genrand():
global mt, mti
mag01 = [0x0L, MATRIX_A]
# mag01[x] = x * MATRIX_A for x=0,1
y = 0
if mti >= N: # generate N words at one time
if mti == N+1: # if sgenrand() has not been called,
sgenrand(4357) # a default initial seed is used
for kk in xrange((N-M) + 1):
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK)
mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1]
for kk in xrange(kk, N):
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK)
mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1]
y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK)
mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1]
mti = 0
y = mt[mti]
mti += 1
y ^= TEMPERING_SHIFT_U(y)
y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B
y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C
y ^= TEMPERING_SHIFT_L(y)
return ( float(y) / 0xffffffffL ) # reals
#------ Mersenne Twister -- end
""" 2d convexhull
Based from Dinu C. Gherman's work,
modified for Blender/Mathutils by Campell Barton
"""
######################################################################
# Public interface
######################################################################
from Blender.Mathutils import DotVecs
def convexHull(point_list_2d):
"""Calculate the convex hull of a set of vectors
The vectors can be 3 or 4d but only the Xand Y are used.
returns a list of convex hull indicies to the given point list
"""
######################################################################
# Helpers
######################################################################
def _myDet(p, q, r):
"""Calc. determinant of a special matrix with three 2D points.
The sign, "-" or "+", determines the side, right or left,
respectivly, on which the point r lies, when measured against
a directed vector from p to q.
"""
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)
def _isRightTurn((p, q, r)):
"Do the vectors pq:qr form a right turn, or not?"
#assert p[0] != q[0] and q[0] != r[0] and p[0] != r[0]
if _myDet(p[0], q[0], r[0]) < 0:
return 1
else:
return 0
# Get a local list copy of the points and sort them lexically.
points = [(p, i) for i, p in enumerate(point_list_2d)]
try: points.sort(key = lambda a: (a[0].x, a[0].y))
except: points.sort(lambda a,b: cmp((a[0].x, a[0].y), (b[0].x, b[0].y)))
# Build upper half of the hull.
upper = [points[0], points[1]] # cant remove these.
for i in xrange(len(points)-2):
upper.append(points[i+2])
while len(upper) > 2 and not _isRightTurn(upper[-3:]):
del upper[-2]
# Build lower half of the hull.
points.reverse()
lower = [points.pop(0), points.pop(1)]
for p in points:
lower.append(p)
while len(lower) > 2 and not _isRightTurn(lower[-3:]):
del lower[-2]
# Concatenate both halfs and return.
return [p[1] for ls in (upper, lower) for p in ls]
def plane2mat(plane, normalize= False):
'''
Takes a plane and converts to a matrix
points between 0 and 1 are up
1 and 2 are right
assumes the plane has 90d corners
'''
cent= (plane[0]+plane[1]+plane[2]+plane[3] ) /4.0
up= cent - ((plane[0]+plane[1])/2.0)
right= cent - ((plane[1]+plane[2])/2.0)
z= CrossVecs(up, right)
if normalize:
up.normalize()
right.normalize()
z.normalize()
mat= Matrix(up, right, z)
# translate
mat.resize4x4()
tmat= Blender.Mathutils.TranslationMatrix(cent)
return mat * tmat
# Used for mesh_solidify.py and mesh_wire.py
# returns a length from an angle
# Imaging a 2d space.
# there is a hoz line at Y1 going to inf on both X ends, never moves (LINEA)
# down at Y0 is a unit length line point up at (angle) from X0,Y0 (LINEB)
# This function returns the length of LINEB at the point it would intersect LINEA
# - Use this for working out how long to make the vector - differencing it from surrounding faces,
# import math
from math import pi, sin, cos, sqrt
def angleToLength(angle):
# Alredy accounted for
if angle < 0.000001:
return 1.0
angle = 2*pi*angle/360
x,y = cos(angle), sin(angle)
# print "YX", x,y
# 0 d is hoz to the right.
# 90d is vert upward.
fac=1/x
x=x*fac
y=y*fac
return sqrt((x*x)+(y*y))