# -*- coding: ISO-8859-1 -*- # # # Copyright (C) 2002-2004 Jörg Lehmann # Copyright (C) 2002-2004 André Wobst # # This file is part of PyX (http://pyx.sourceforge.net/). # # PyX 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. # # PyX 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 PyX; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA import types scale = { 't':1, 'u':1, 'v':1, 'w':1, 'x':1 } _default_unit = "cm" _m = { 'm' : 1, 'cm': 0.01, 'mm': 0.001, 'inch': 0.01*2.54, 'pt': 0.01*2.54/72, } def set(uscale=None, vscale=None, wscale=None, xscale=None, defaultunit=None): if uscale is not None: scale['u'] = uscale if vscale is not None: scale['v'] = vscale if wscale is not None: scale['w'] = wscale if xscale is not None: scale['x'] = xscale if defaultunit is not None: global _default_unit _default_unit = defaultunit def _convert_to(l, dest_unit="m"): if type(l) in (types.IntType, types.LongType, types.FloatType): return l * _m[_default_unit] * scale['u'] / _m[dest_unit] elif not isinstance(l, length): l = length(l) # convert to length instance if necessary return (l.t + l.u*scale['u'] + l.v*scale['v'] + l.w*scale['w'] + l.x*scale['x']) / _m[dest_unit] def tom(l): return _convert_to(l, "m") def tocm(l): return _convert_to(l, "cm") def tomm(l): return _convert_to(l, "mm") def toinch(l): return _convert_to(l, "inch") def topt(l): return _convert_to(l, "pt") ################################################################################ # class for generic length ################################################################################ class length: """ PyX lengths PyX lengths are composed of five components (t=true, u=user, v=visual, w=width, and x=TeX) which can be scaled separately (except for the true component, which is always unscaled). Lengths can be constructed in units of "pt", "mm", "cm", "m" and "inch". When no unit is given, a module default is used, which can be changed with the help of the module level function set(). """ def __init__(self, f=0, type="u", unit=None): """ create a length instance of the given type with a length f in the given unit. If unit is not set, the currently set default unit is used. """ self.t = self.u = self.v = self.w = self.x = 0 l = float(f) * _m[unit or _default_unit] if type == "t": self.t = l elif type == "u": self.u = l elif type == "v": self.v = l elif type == "w": self.w = l elif type == "x": self.x = l def __cmp__(self, other): # we try to convert self and other into meters and # if this fails, we give other a chance to do the comparison try: return cmp(tom(self), tom(other)) except: # why does -cmp(other, self) not work? return -other.__cmp__(self) def __mul__(self, factor): result = length() result.t = factor * self.t result.u = factor * self.u result.v = factor * self.v result.w = factor * self.w result.x = factor * self.x return result __rmul__=__mul__ def __div__(self, divisor): if isinstance(divisor, length): return tom(self) / tom(divisor) result = length() result.t = self.t / divisor result.u = self.u / divisor result.v = self.v / divisor result.w = self.w / divisor result.x = self.x / divisor return result __truediv__ = __div__ def __add__(self, other): # convert to length if necessary if not isinstance(other, length): # if other is not a length, we try to convert it into a length and # if this fails, we give other a chance to do the addition try: other = length(other) except: return other + self result = length() result.t = self.t + other.t result.u = self.u + other.u result.v = self.v + other.v result.w = self.w + other.w result.x = self.x + other.x return result __radd__ = __add__ def __sub__(self, other): # convert to length if necessary if not isinstance(other, length): # if other is not a length, we try to convert it into a length and # if this fails, we give other a chance to do the subtraction try: other = length(other) except: return -other + self result = length() result.t = self.t - other.t result.u = self.u - other.u result.v = self.v - other.v result.w = self.w - other.w result.x = self.x - other.x return result def __rsub__(self, other): # convert to length if necessary if not isinstance(other, length): other = length(other) result = length() result.t = other.t - self.t result.u = other.u - self.u result.v = other.v - self.v result.w = other.w - self.w result.x = other.x - self.x return result def __neg__(self): result = length() result.t = -self.t result.u = -self.u result.v = -self.v result.w = -self.w result.x = -self.x return result def __str__(self): return "(%(t)f t + %(u)f u + %(v)f v + %(w)f w + %(x)f x) m" % self.__dict__ ################################################################################ # predefined instances which can be used as length units ################################################################################ # user lengths and unqualified length which are also user length u_pt = pt = length(1, type="u", unit="pt") u_m = m = length(1, type="u", unit="m") u_mm = mm = length(1, type="u", unit="mm") u_cm = cm = length(1, type="u", unit="cm") u_inch = inch = length(1, type="u", unit="inch") # true lengths t_pt = length(1, type="t", unit="pt") t_m = length(1, type="t", unit="m") t_mm = length(1, type="t", unit="mm") t_cm = length(1, type="t", unit="cm") t_inch = length(1, type="t", unit="inch") # visual lengths v_pt = length(1, type="v", unit="pt") v_m = length(1, type="v", unit="m") v_mm = length(1, type="v", unit="mm") v_cm = length(1, type="v", unit="cm") v_inch = length(1, type="v", unit="inch") # width lengths w_pt = length(1, type="w", unit="pt") w_m = length(1, type="w", unit="m") w_mm = length(1, type="w", unit="mm") w_cm = length(1, type="w", unit="cm") w_inch = length(1, type="w", unit="inch") # TeX lengths x_pt = length(1, type="x", unit="pt") x_m = length(1, type="x", unit="m") x_mm = length(1, type="x", unit="mm") x_cm = length(1, type="x", unit="cm") x_inch = length(1, type="x", unit="inch")