pyx/bbox.py

   1 #!/usr/bin/env python
   2 # -*- coding: ISO-8859-1 -*-
   3 #
   4 #
   5 # Copyright (C) 2002-2005 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 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 lowrestuple_pt(self):
  71         return (math.floor(self.llx_pt), math.floor(self.lly_pt),
  72                 math.ceil(self.urx_pt), math.ceil(self.ury_pt))
  73
  74     def highrestuple_pt(self):
  75         return (self.llx_pt, self.lly_pt, self.urx_pt, self.ury_pt)
  76
  77     def intersects(self, other):
  78         """check, if two bboxes intersect eachother"""
  79         return not (self.llx_pt > other.urx_pt or
  80                     self.lly_pt > other.ury_pt or
  81                     self.urx_pt < other.llx_pt or
  82                     self.ury_pt < other.lly_pt)
  83
  84     def transform(self, trafo):
  85         """transform bbox in place by trafo"""
  86         # we have to transform all four corner points of the bbox
  87         llx_pt, lly_pt = trafo._apply(self.llx_pt, self.lly_pt)
  88         lrx, lry = trafo._apply(self.urx_pt, self.lly_pt)
  89         urx_pt, ury_pt = trafo._apply(self.urx_pt, self.ury_pt)
  90         ulx, uly = trafo._apply(self.llx_pt, self.ury_pt)
  91
  92         # Now, by sorting, we obtain the lower left and upper right corner
  93         # of the new bounding box.
  94         self.llx_pt = min(llx_pt, lrx, urx_pt, ulx)
  95         self.lly_pt = min(lly_pt, lry, ury_pt, uly)
  96         self.urx_pt = max(llx_pt, lrx, urx_pt, ulx)
  97         self.ury_pt = max(lly_pt, lry, ury_pt, uly)
  98
  99     def transformed(self, trafo):
 100         """return bbox transformed by trafo"""
 101         # we have to transform all four corner points of the bbox
 102         llx_pt, lly_pt = trafo._apply(self.llx_pt, self.lly_pt)
 103         lrx, lry = trafo._apply(self.urx_pt, self.lly_pt)
 104         urx_pt, ury_pt = trafo._apply(self.urx_pt, self.ury_pt)
 105         ulx, uly = trafo._apply(self.llx_pt, self.ury_pt)
 106
 107         # Now, by sorting, we obtain the lower left and upper right corner
 108         # of the new bounding box.
 109         return bbox_pt(min(llx_pt, lrx, urx_pt, ulx), min(lly_pt, lry, ury_pt, uly),
 110                      max(llx_pt, lrx, urx_pt, ulx), max(lly_pt, lry, ury_pt, uly))
 111
 112     def enlarge(self, all=0, bottom=None, left=None, top=None, right=None):
 113         """enlarge bbox in place
 114
 115         all is used, if bottom, left, top and/or right are not given.
 116
 117         """
 118         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 119         if bottom is not None:
 120            bottom_pt = unit.topt(bottom)
 121         if left is not None:
 122            left_pt = unit.topt(left)
 123         if top is not None:
 124            top_pt = unit.topt(top)
 125         if right is not None:
 126            right_pt = unit.topt(right)
 127         self.llx_pt -= left_pt
 128         self.lly_pt -= bottom_pt
 129         self.urx_pt += right_pt
 130         self.ury_pt += top_pt
 131
 132     def enlarged(self, all=0, bottom=None, left=None, top=None, right=None):
 133         """return bbox enlarged
 134
 135         all is used, if bottom, left, top and/or right are not given.
 136
 137         """
 138         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 139         if bottom is not None:
 140            bottom_pt = unit.topt(bottom)
 141         if left is not None:
 142            left_pt = unit.topt(left)
 143         if top is not None:
 144            top_pt = unit.topt(top)
 145         if right is not None:
 146            right_pt = unit.topt(right)
 147         return bbox_pt(self.llx_pt-left_pt, self.lly_pt-bottom_pt, self.urx_pt+right_pt, self.ury_pt+top_pt)
 148
 149     def rect(self):
 150         """return rectangle corresponding to bbox"""
 151         import path
 152         return path.rect_pt(self.llx_pt, self.lly_pt, self.urx_pt-self.llx_pt, self.ury_pt-self.lly_pt)
 153
 154     path = rect
 155
 156     def height_pt(self):
 157         """return height of bbox in pts"""
 158         return self.ury_pt-self.lly_pt
 159
 160     def width_pt(self):
 161         """return width of bbox in pts"""
 162         return self.urx_pt-self.llx_pt
 163
 164     def top_pt(self):
 165         """return top coordinate of bbox in pts"""
 166         return self.ury_pt
 167
 168     def bottom_pt(self):
 169         """return bottom coordinate of bbox in pts"""
 170         return self.lly_pt
 171
 172     def left_pt(self):
 173         """return left coordinate of bbox in pts"""
 174         return self.llx_pt
 175
 176     def right_pt(self):
 177         """return right coordinate of bbox in pts"""
 178         return self.urx_pt
 179
 180     def center_pt(self):
 181         """return coordinates of the center of the bbox in pts"""
 182         return 0.5 * (self.llx_pt+self.urx_pt), 0.5 * (self.lly_pt+self.ury_pt)
 183
 184     def height(self):
 185         """return height of bbox"""
 186         return self.height_pt() * unit.t_pt
 187
 188     def width(self):
 189         """return width of bbox"""
 190         return self.width_pt() * unit.t_pt
 191
 192     def top(self):
 193         """return top coordinate of bbox"""
 194         return self.ury_pt * unit.t_pt
 195
 196     def bottom(self):
 197         """return bottom coordinate of bbox"""
 198         return self.lly_pt * unit.t_pt
 199
 200     def left(self):
 201         """return left coordinate of bbox"""
 202         return self.llx_pt * unit.t_pt
 203
 204     def right(self):
 205         """return right coordinate of bbox"""
 206         return self.urx_pt * unit.t_pt
 207
 208     def center(self):
 209         """return coordinates of the center of the bbox"""
 210         centerx_pt, centery_pt = self.center_pt()
 211         return centerx_pt * unit.t_pt, centery_pt * unit.t_pt
 212
 213
 214 class bbox(bbox_pt):
 215
 216     """class for bounding boxes"""
 217
 218     def __init__(self, llx_pt, lly_pt, urx_pt, ury_pt):
 219         llx_pt = unit.topt(llx_pt)
 220         lly_pt = unit.topt(lly_pt)
 221         urx_pt = unit.topt(urx_pt)
 222         ury_pt = unit.topt(ury_pt)
 223         bbox_pt.__init__(self, llx_pt, lly_pt, urx_pt, ury_pt)