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 includepoint_pt(self, x_pt, y_pt):
  85         self.llx_pt = min(self.llx_pt, x_pt)
  86         self.lly_pt = min(self.lly_pt, y_pt)
  87         self.urx_pt = max(self.urx_pt, x_pt)
  88         self.ury_pt = max(self.ury_pt, y_pt)
  89
  90     def transform(self, trafo):
  91         """transform bbox in place by trafo"""
  92         # we have to transform all four corner points of the bbox
  93         llx_pt, lly_pt = trafo.apply_pt(self.llx_pt, self.lly_pt)
  94         lrx, lry = trafo.apply_pt(self.urx_pt, self.lly_pt)
  95         urx_pt, ury_pt = trafo.apply_pt(self.urx_pt, self.ury_pt)
  96         ulx, uly = trafo.apply_pt(self.llx_pt, self.ury_pt)
  97
  98         # Now, by sorting, we obtain the lower left and upper right corner
  99         # of the new bounding box.
 100         self.llx_pt = min(llx_pt, lrx, urx_pt, ulx)
 101         self.lly_pt = min(lly_pt, lry, ury_pt, uly)
 102         self.urx_pt = max(llx_pt, lrx, urx_pt, ulx)
 103         self.ury_pt = max(lly_pt, lry, ury_pt, uly)
 104
 105     def transformed(self, trafo):
 106         """return bbox transformed by trafo"""
 107         # we have to transform all four corner points of the bbox
 108         llx_pt, lly_pt = trafo.apply_pt(self.llx_pt, self.lly_pt)
 109         lrx, lry = trafo.apply_pt(self.urx_pt, self.lly_pt)
 110         urx_pt, ury_pt = trafo.apply_pt(self.urx_pt, self.ury_pt)
 111         ulx, uly = trafo.apply_pt(self.llx_pt, self.ury_pt)
 112
 113         # Now, by sorting, we obtain the lower left and upper right corner
 114         # of the new bounding box.
 115         return bbox_pt(min(llx_pt, lrx, urx_pt, ulx), min(lly_pt, lry, ury_pt, uly),
 116                      max(llx_pt, lrx, urx_pt, ulx), max(lly_pt, lry, ury_pt, uly))
 117
 118     def enlarge(self, all=0, bottom=None, left=None, top=None, right=None):
 119         """enlarge bbox in place
 120
 121         all is used, if bottom, left, top and/or right are not given.
 122
 123         """
 124         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 125         if bottom is not None:
 126            bottom_pt = unit.topt(bottom)
 127         if left is not None:
 128            left_pt = unit.topt(left)
 129         if top is not None:
 130            top_pt = unit.topt(top)
 131         if right is not None:
 132            right_pt = unit.topt(right)
 133         self.llx_pt -= left_pt
 134         self.lly_pt -= bottom_pt
 135         self.urx_pt += right_pt
 136         self.ury_pt += top_pt
 137
 138     def enlarged(self, all=0, bottom=None, left=None, top=None, right=None):
 139         """return bbox enlarged
 140
 141         all is used, if bottom, left, top and/or right are not given.
 142
 143         """
 144         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 145         if bottom is not None:
 146            bottom_pt = unit.topt(bottom)
 147         if left is not None:
 148            left_pt = unit.topt(left)
 149         if top is not None:
 150            top_pt = unit.topt(top)
 151         if right is not None:
 152            right_pt = unit.topt(right)
 153         return bbox_pt(self.llx_pt-left_pt, self.lly_pt-bottom_pt, self.urx_pt+right_pt, self.ury_pt+top_pt)
 154
 155     def rect(self):
 156         """return rectangle corresponding to bbox"""
 157         import path
 158         return path.rect_pt(self.llx_pt, self.lly_pt, self.urx_pt-self.llx_pt, self.ury_pt-self.lly_pt)
 159
 160     path = rect
 161
 162     def height_pt(self):
 163         """return height of bbox in pts"""
 164         return self.ury_pt-self.lly_pt
 165
 166     def width_pt(self):
 167         """return width of bbox in pts"""
 168         return self.urx_pt-self.llx_pt
 169
 170     def top_pt(self):
 171         """return top coordinate of bbox in pts"""
 172         return self.ury_pt
 173
 174     def bottom_pt(self):
 175         """return bottom coordinate of bbox in pts"""
 176         return self.lly_pt
 177
 178     def left_pt(self):
 179         """return left coordinate of bbox in pts"""
 180         return self.llx_pt
 181
 182     def right_pt(self):
 183         """return right coordinate of bbox in pts"""
 184         return self.urx_pt
 185
 186     def center_pt(self):
 187         """return coordinates of the center of the bbox in pts"""
 188         return 0.5 * (self.llx_pt+self.urx_pt), 0.5 * (self.lly_pt+self.ury_pt)
 189
 190     def height(self):
 191         """return height of bbox"""
 192         return self.height_pt() * unit.t_pt
 193
 194     def width(self):
 195         """return width of bbox"""
 196         return self.width_pt() * unit.t_pt
 197
 198     def top(self):
 199         """return top coordinate of bbox"""
 200         return self.ury_pt * unit.t_pt
 201
 202     def bottom(self):
 203         """return bottom coordinate of bbox"""
 204         return self.lly_pt * unit.t_pt
 205
 206     def left(self):
 207         """return left coordinate of bbox"""
 208         return self.llx_pt * unit.t_pt
 209
 210     def right(self):
 211         """return right coordinate of bbox"""
 212         return self.urx_pt * unit.t_pt
 213
 214     def center(self):
 215         """return coordinates of the center of the bbox"""
 216         centerx_pt, centery_pt = self.center_pt()
 217         return centerx_pt * unit.t_pt, centery_pt * unit.t_pt
 218
 219
 220 class bbox(bbox_pt):
 221
 222     """class for bounding boxes"""
 223
 224     def __init__(self, llx_pt, lly_pt, urx_pt, ury_pt):
 225         llx_pt = unit.topt(llx_pt)
 226         lly_pt = unit.topt(lly_pt)
 227         urx_pt = unit.topt(urx_pt)
 228         ury_pt = unit.topt(ury_pt)
 229         bbox_pt.__init__(self, llx_pt, lly_pt, urx_pt, ury_pt)