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_pt:
  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_pt, lly_pt, urx_pt, ury_pt):
  39         self.llx_pt = llx_pt
  40         self.lly_pt = lly_pt
  41         self.urx_pt = urx_pt
  42         self.ury_pt = ury_pt
  43
  44     def __add__(self, other):
  45         """join two bboxes"""
  46         return bbox_pt(min(self.llx_pt, other.llx_pt), min(self.lly_pt, other.lly_pt),
  47                      max(self.urx_pt, other.urx_pt), max(self.ury_pt, other.ury_pt))
  48
  49     def __iadd__(self, other):
  50         """join two bboxes inplace"""
  51         self.llx_pt = min(self.llx_pt, other.llx_pt)
  52         self.lly_pt = min(self.lly_pt, other.lly_pt)
  53         self.urx_pt = max(self.urx_pt, other.urx_pt)
  54         self.ury_pt = max(self.ury_pt, other.ury_pt)
  55         return self
  56
  57     def __mul__(self, other):
  58         """return intersection of two bboxes"""
  59         return bbox_pt(max(self.llx_pt, other.llx_pt), max(self.lly_pt, other.lly_pt),
  60                      min(self.urx_pt, other.urx_pt), min(self.ury_pt, other.ury_pt))
  61
  62     def __imul__(self, other):
  63         """intersect two bboxes in place"""
  64         self.llx_pt = max(self.llx_pt, other.llx_pt)
  65         self.lly_pt = max(self.lly_pt, other.lly_pt)
  66         self.urx_pt = min(self.urx_pt, other.urx_pt)
  67         self.ury_pt = min(self.ury_pt, other.ury_pt)
  68         return self
  69
  70     def __str__(self):
  71         return "%s %s %s %s" % (self.llx_pt, self.lly_pt, self.urx_pt, self.ury_pt)
  72
  73     def outputPS(self, file):
  74         file.write("%%%%BoundingBox: %d %d %d %d\n" %
  75                    (math.floor(self.llx_pt), math.floor(self.lly_pt),
  76                     math.ceil(self.urx_pt), math.ceil(self.ury_pt)))
  77         file.write("%%%%HiResBoundingBox: %g %g %g %g\n" %
  78                    (self.llx_pt, self.lly_pt, self.urx_pt, self.ury_pt))
  79
  80     def outputPDF(self, file):
  81         file.write("[%d %d %d %d]\n" %
  82                    (math.floor(self.llx_pt), math.floor(self.lly_pt),
  83                     math.ceil(self.urx_pt), math.ceil(self.ury_pt)))
  84
  85     def intersects(self, other):
  86         """check, if two bboxes intersect eachother"""
  87         return not (self.llx_pt > other.urx_pt or
  88                     self.lly_pt > other.ury_pt or
  89                     self.urx_pt < other.llx_pt or
  90                     self.ury_pt < other.lly_pt)
  91
  92     def transform(self, trafo):
  93         """transform bbox in place by trafo"""
  94         # we have to transform all four corner points of the bbox
  95         llx_pt, lly_pt = trafo._apply(self.llx_pt, self.lly_pt)
  96         lrx, lry = trafo._apply(self.urx_pt, self.lly_pt)
  97         urx_pt, ury_pt = trafo._apply(self.urx_pt, self.ury_pt)
  98         ulx, uly = trafo._apply(self.llx_pt, self.ury_pt)
  99
 100         # Now, by sorting, we obtain the lower left and upper right corner
 101         # of the new bounding box.
 102         self.llx_pt = min(llx_pt, lrx, urx_pt, ulx)
 103         self.lly_pt = min(lly_pt, lry, ury_pt, uly)
 104         self.urx_pt = max(llx_pt, lrx, urx_pt, ulx)
 105         self.ury_pt = max(lly_pt, lry, ury_pt, uly)
 106
 107     def transformed(self, trafo):
 108         """return bbox transformed by trafo"""
 109         # we have to transform all four corner points of the bbox
 110         llx_pt, lly_pt = trafo._apply(self.llx_pt, self.lly_pt)
 111         lrx, lry = trafo._apply(self.urx_pt, self.lly_pt)
 112         urx_pt, ury_pt = trafo._apply(self.urx_pt, self.ury_pt)
 113         ulx, uly = trafo._apply(self.llx_pt, self.ury_pt)
 114
 115         # Now, by sorting, we obtain the lower left and upper right corner
 116         # of the new bounding box.
 117         return bbox_pt(min(llx_pt, lrx, urx_pt, ulx), min(lly_pt, lry, ury_pt, uly),
 118                      max(llx_pt, lrx, urx_pt, ulx), max(lly_pt, lry, ury_pt, uly))
 119
 120     def enlarge(self, all=0, bottom=None, left=None, top=None, right=None):
 121         """enlarge bbox in place
 122
 123         all is used, if bottom, left, top and/or right are not given.
 124
 125         """
 126         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 127         if bottom is not None:
 128            bottom_pt = unit.topt(bottom)
 129         if left is not None:
 130            left_pt = unit.topt(left)
 131         if top is not None:
 132            top_pt = unit.topt(top)
 133         if right is not None:
 134            right_pt = unit.topt(right)
 135         self.llx_pt -= left_pt
 136         self.lly_pt -= bottom_pt
 137         self.urx_pt += right_pt
 138         self.ury_pt += top_pt
 139
 140     def enlarged(self, all=0, bottom=None, left=None, top=None, right=None):
 141         """return bbox enlarged
 142
 143         all is used, if bottom, left, top and/or right are not given.
 144
 145         """
 146         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 147         if bottom is not None:
 148            bottom_pt = unit.topt(bottom)
 149         if left is not None:
 150            left_pt = unit.topt(left)
 151         if top is not None:
 152            top_pt = unit.topt(top)
 153         if right is not None:
 154            right_pt = unit.topt(right)
 155         return bbox_pt(self.llx_pt-left_pt, self.lly_pt-bottom_pt, self.urx_pt+right_pt, self.ury_pt+top_pt)
 156
 157     def rect(self):
 158         """return rectangle corresponding to bbox"""
 159         import path
 160         return path.rect_pt(self.llx_pt, self.lly_pt, self.urx_pt-self.llx_pt, self.ury_pt-self.lly_pt)
 161
 162     path = rect
 163
 164     def height(self):
 165         """return height of bbox"""
 166         return (self.ury_pt-self.lly_pt) * unit.t_pt
 167
 168     def width(self):
 169         """return width of bbox"""
 170         return (self.urx_pt-self.llx_pt) * unit.t_pt
 171
 172     def top(self):
 173         """return top coordinate of bbox"""
 174         return self.ury_pt * unit.t_pt
 175
 176     def bottom(self):
 177         """return bottom coordinate of bbox"""
 178         return self.lly_pt * unit.t_pt
 179
 180     def left(self):
 181         """return left coordinate of bbox"""
 182         return self.llx_pt * unit.t_pt
 183
 184     def right(self):
 185         """return right coordinate of bbox"""
 186         return self.urx_pt * unit.t_pt
 187
 188     def center(self):
 189         """return coordinates of the center of the bbox"""
 190         return 0.5 * (self.llx_pt+self.urx_pt) * unit.t_pt, 0.5 * (self.lly_pt+self.ury_pt) * unit.t_pt
 191
 192
 193 class bbox(bbox_pt):
 194
 195     """class for bounding boxes"""
 196
 197     def __init__(self, llx_pt, lly_pt, urx_pt, ury_pt):
 198         llx_pt = unit.topt(llx_pt)
 199         lly_pt = unit.topt(lly_pt)
 200         urx_pt = unit.topt(urx_pt)
 201         ury_pt = unit.topt(ury_pt)
 202         bbox_pt.__init__(self, llx_pt, lly_pt, urx_pt, ury_pt)