pyx/bbox.py

   1 #!/usr/bin/env python
   2 # -*- coding: ISO-8859-1 -*-
   3 #
   4 #
   5 # Copyright (C) 2002-2004 Jörg Lehmann <joergl@users.sourceforge.net>
   6 # Copyright (C) 2002-2004 André Wobst <wobsta@users.sourceforge.net>
   7 #
   8 # This file is part of PyX (http://pyx.sourceforge.net/).
   9 #
  10 # PyX is free software; you can redistribute it and/or modify
  11 # it under the terms of the GNU General Public License as published by
  12 # the Free Software Foundation; either version 2 of the License, or
  13 # (at your option) any later version.
  14 #
  15 # PyX is distributed in the hope that it will be useful,
  16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 # GNU General Public License for more details.
  19 #
  20 # You should have received a copy of the GNU General Public License
  21 # along with PyX; if not, write to the Free Software
  22 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23
  24 import math
  25 import unit
  26
  27 #
  28 # classes representing bounding boxes
  29 #
  30
  31 class _bbox:
  32
  33     """class for bounding boxes
  34
  35     This variant requires points in the constructor, and is used for internal
  36     purposes."""
  37
  38     def __init__(self, llx, lly, urx, ury):
  39         self.llx = llx
  40         self.lly = lly
  41         self.urx = urx
  42         self.ury = ury
  43
  44     def __add__(self, other):
  45         """join two bboxes"""
  46         return _bbox(min(self.llx, other.llx), min(self.lly, other.lly),
  47                      max(self.urx, other.urx), max(self.ury, other.ury))
  48
  49     def __iadd__(self, other):
  50         """join two bboxes inplace"""
  51         self.llx = min(self.llx, other.llx)
  52         self.lly = min(self.lly, other.lly)
  53         self.urx = max(self.urx, other.urx)
  54         self.ury = max(self.ury, other.ury)
  55         return self
  56
  57     def __mul__(self, other):
  58         """return intersection of two bboxes"""
  59         return _bbox(max(self.llx, other.llx), max(self.lly, other.lly),
  60                      min(self.urx, other.urx), min(self.ury, other.ury))
  61
  62     def __imul__(self, other):
  63         """intersect two bboxes in place"""
  64         self.llx = max(self.llx, other.llx)
  65         self.lly = max(self.lly, other.lly)
  66         self.urx = min(self.urx, other.urx)
  67         self.ury = min(self.ury, other.ury)
  68         return self
  69
  70     def __str__(self):
  71         return "%s %s %s %s" % (self.llx, self.lly, self.urx, self.ury)
  72
  73     def outputPS(self, file):
  74         file.write("%%%%BoundingBox: %d %d %d %d\n" %
  75                    (math.floor(self.llx), math.floor(self.lly),
  76                     math.ceil(self.urx), math.ceil(self.ury)))
  77         file.write("%%%%HiResBoundingBox: %g %g %g %g\n" %
  78                    (self.llx, self.lly, self.urx, self.ury))
  79
  80     def intersects(self, other):
  81         """check, if two bboxes intersect eachother"""
  82         return not (self.llx > other.urx or
  83                     self.lly > other.ury or
  84                     self.urx < other.llx or
  85                     self.ury < other.lly)
  86
  87     def transform(self, trafo):
  88         """transform bbox in place by trafo"""
  89         # we have to transform all four corner points of the bbox
  90         llx, lly = trafo._apply(self.llx, self.lly)
  91         lrx, lry = trafo._apply(self.urx, self.lly)
  92         urx, ury = trafo._apply(self.urx, self.ury)
  93         ulx, uly = trafo._apply(self.llx, self.ury)
  94
  95         # Now, by sorting, we obtain the lower left and upper right corner
  96         # of the new bounding box.
  97         self.llx = min(llx, lrx, urx, ulx)
  98         self.lly = min(lly, lry, ury, uly)
  99         self.urx = max(llx, lrx, urx, ulx)
 100         self.ury = max(lly, lry, ury, uly)
 101
 102     def transformed(self, trafo):
 103         """return bbox transformed by trafo"""
 104         # we have to transform all four corner points of the bbox
 105         llx, lly = trafo._apply(self.llx, self.lly)
 106         lrx, lry = trafo._apply(self.urx, self.lly)
 107         urx, ury = trafo._apply(self.urx, self.ury)
 108         ulx, uly = trafo._apply(self.llx, self.ury)
 109
 110         # Now, by sorting, we obtain the lower left and upper right corner
 111         # of the new bounding box.
 112         return _bbox(min(llx, lrx, urx, ulx), min(lly, lry, ury, uly),
 113                      max(llx, lrx, urx, ulx), max(lly, lry, ury, uly))
 114
 115     def enlarged(self, all=0, bottom=None, left=None, top=None, right=None):
 116         """enlarge bbox in place
 117
 118         all is used, if bottom, left, top and/or right are not given.
 119
 120         """
 121         _bottom = _left = _top = _right = unit.topt(unit.length(all, default_type="v"))
 122         if bottom is not None:
 123            _bottom = unit.topt(unit.length(bottom, default_type="v"))
 124         if left is not None:
 125            _left = unit.topt(unit.length(left, default_type="v"))
 126         if top is not None:
 127            _top = unit.topt(unit.length(top, default_type="v"))
 128         if right is not None:
 129            _right = unit.topt(unit.length(right, default_type="v"))
 130         self.llx -= _left
 131         self.lly -= _bottom
 132         self.urx += _right
 133         self.ury += top
 134
 135     def enlarged(self, all=0, bottom=None, left=None, top=None, right=None):
 136         """return bbox enlarged
 137
 138         all is used, if bottom, left, top and/or right are not given.
 139
 140         """
 141         _bottom = _left = _top = _right = unit.topt(unit.length(all, default_type="v"))
 142         if bottom is not None:
 143            _bottom = unit.topt(unit.length(bottom, default_type="v"))
 144         if left is not None:
 145            _left = unit.topt(unit.length(left, default_type="v"))
 146         if top is not None:
 147            _top = unit.topt(unit.length(top, default_type="v"))
 148         if right is not None:
 149            _right = unit.topt(unit.length(right, default_type="v"))
 150         return _bbox(self.llx-_left, self.lly-_bottom, self.urx+_right, self.ury+_top)
 151
 152     def rect(self):
 153         """return rectangle corresponding to bbox"""
 154         import path
 155         return path.rect_pt(self.llx, self.lly, self.urx-self.llx, self.ury-self.lly)
 156
 157     path = rect
 158
 159     def height(self):
 160         """return height of bbox"""
 161         return unit.t_pt(self.ury-self.lly)
 162
 163     def width(self):
 164         """return width of bbox"""
 165         return unit.t_pt(self.urx-self.llx)
 166
 167     def top(self):
 168         """return top coordinate of bbox"""
 169         return unit.t_pt(self.ury)
 170
 171     def bottom(self):
 172         """return bottom coordinate of bbox"""
 173         return unit.t_pt(self.lly)
 174
 175     def left(self):
 176         """return left coordinate of bbox"""
 177         return unit.t_pt(self.llx)
 178
 179     def right(self):
 180         """return right coordinate of bbox"""
 181         return unit.t_pt(self.urx)
 182
 183
 184 class bbox(_bbox):
 185
 186     """class for bounding boxes"""
 187
 188     def __init__(self, llx, lly, urx, ury):
 189         llx = unit.topt(llx)
 190         lly = unit.topt(lly)
 191         urx = unit.topt(urx)
 192         ury = unit.topt(ury)
 193         _bbox.__init__(self, llx, lly, urx, ury)
 194