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 copy(self):
  71         return bbox_pt(self.llx_pt, self.lly_pt, self.urx_pt, self.ury_pt)
  72
  73     def lowrestuple_pt(self):
  74         return (math.floor(self.llx_pt), math.floor(self.lly_pt),
  75                 math.ceil(self.urx_pt), math.ceil(self.ury_pt))
  76
  77     def highrestuple_pt(self):
  78         return (self.llx_pt, self.lly_pt, self.urx_pt, self.ury_pt)
  79
  80     def intersects(self, other):
  81         """check, if two bboxes intersect eachother"""
  82         return not (self.llx_pt > other.urx_pt or
  83                     self.lly_pt > other.ury_pt or
  84                     self.urx_pt < other.llx_pt or
  85                     self.ury_pt < other.lly_pt)
  86
  87     def includepoint_pt(self, x_pt, y_pt):
  88         self.llx_pt = min(self.llx_pt, x_pt)
  89         self.lly_pt = min(self.lly_pt, y_pt)
  90         self.urx_pt = max(self.urx_pt, x_pt)
  91         self.ury_pt = max(self.ury_pt, y_pt)
  92
  93     def transform(self, trafo):
  94         """transform bbox in place by trafo"""
  95         # we have to transform all four corner points of the bbox
  96         llx_pt, lly_pt = trafo.apply_pt(self.llx_pt, self.lly_pt)
  97         lrx_pt, lry_pt = trafo.apply_pt(self.urx_pt, self.lly_pt)
  98         urx_pt, ury_pt = trafo.apply_pt(self.urx_pt, self.ury_pt)
  99         ulx_pt, uly_pt = trafo.apply_pt(self.llx_pt, self.ury_pt)
 100
 101         # Now, by sorting, we obtain the lower left and upper right corner
 102         # of the new bounding box.
 103         self.llx_pt = min(llx_pt, lrx_pt, urx_pt, ulx_pt)
 104         self.lly_pt = min(lly_pt, lry_pt, ury_pt, uly_pt)
 105         self.urx_pt = max(llx_pt, lrx_pt, urx_pt, ulx_pt)
 106         self.ury_pt = max(lly_pt, lry_pt, ury_pt, uly_pt)
 107
 108     def transformed(self, trafo):
 109         """return bbox transformed by trafo"""
 110         # we have to transform all four corner points of the bbox
 111         llx_pt, lly_pt = trafo.apply_pt(self.llx_pt, self.lly_pt)
 112         lrx_pt, lry_pt = trafo.apply_pt(self.urx_pt, self.lly_pt)
 113         urx_pt, ury_pt = trafo.apply_pt(self.urx_pt, self.ury_pt)
 114         ulx_pt, uly_pt = trafo.apply_pt(self.llx_pt, self.ury_pt)
 115
 116         # Now, by sorting, we obtain the lower left and upper right corner
 117         # of the new bounding box.
 118         return bbox_pt(min(llx_pt, lrx_pt, urx_pt, ulx_pt), min(lly_pt, lry_pt, ury_pt, uly_pt),
 119                        max(llx_pt, lrx_pt, urx_pt, ulx_pt), max(lly_pt, lry_pt, ury_pt, uly_pt))
 120
 121     def enlarge_pt(self, all_pt=0, bottom_pt=None, left_pt=None, top_pt=None, right_pt=None):
 122         """enlarge bbox in place by the given amounts in pts
 123
 124         all is used, if bottom, left, top and/or right are not given.
 125
 126         """
 127         if bottom_pt is None:
 128            bottom_pt = all_pt
 129         if left_pt is None:
 130            left_pt = all_pt
 131         if top_pt is None:
 132            top_pt = all_pt
 133         if right_pt is None:
 134            right_pt = all_pt
 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_pt(self, all_pt=0, bottom_pt=None, left_pt=None, top_pt=None, right_pt=None):
 141         """return bbox enlarged by the given amounts in pts
 142
 143         all is used, if bottom, left, top and/or right are not given.
 144
 145         """
 146         if bottom_pt is None:
 147            bottom_pt = all_pt
 148         if left_pt is None:
 149            left_pt = all_pt
 150         if top_pt is None:
 151            top_pt = all_pt
 152         if right_pt is None:
 153            right_pt = all_pt
 154         return bbox_pt(self.llx_pt-left_pt, self.lly_pt-bottom_pt, self.urx_pt+right_pt, self.ury_pt+top_pt)
 155
 156     def enlarge(self, all=0, bottom=None, left=None, top=None, right=None):
 157         """enlarge bbox in place
 158
 159         all is used, if bottom, left, top and/or right are not given.
 160
 161         """
 162         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 163         if bottom is not None:
 164            bottom_pt = unit.topt(bottom)
 165         if left is not None:
 166            left_pt = unit.topt(left)
 167         if top is not None:
 168            top_pt = unit.topt(top)
 169         if right is not None:
 170            right_pt = unit.topt(right)
 171         self.llx_pt -= left_pt
 172         self.lly_pt -= bottom_pt
 173         self.urx_pt += right_pt
 174         self.ury_pt += top_pt
 175
 176     def enlarged(self, all=0, bottom=None, left=None, top=None, right=None):
 177         """return bbox enlarged
 178
 179         all is used, if bottom, left, top and/or right are not given.
 180
 181         """
 182         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 183         if bottom is not None:
 184            bottom_pt = unit.topt(bottom)
 185         if left is not None:
 186            left_pt = unit.topt(left)
 187         if top is not None:
 188            top_pt = unit.topt(top)
 189         if right is not None:
 190            right_pt = unit.topt(right)
 191         return bbox_pt(self.llx_pt-left_pt, self.lly_pt-bottom_pt, self.urx_pt+right_pt, self.ury_pt+top_pt)
 192
 193     def rect(self):
 194         """return rectangle corresponding to bbox"""
 195         import path
 196         return path.rect_pt(self.llx_pt, self.lly_pt, self.urx_pt-self.llx_pt, self.ury_pt-self.lly_pt)
 197
 198     path = rect
 199
 200     def height_pt(self):
 201         """return height of bbox in pts"""
 202         return self.ury_pt-self.lly_pt
 203
 204     def width_pt(self):
 205         """return width of bbox in pts"""
 206         return self.urx_pt-self.llx_pt
 207
 208     def top_pt(self):
 209         """return top coordinate of bbox in pts"""
 210         return self.ury_pt
 211
 212     def bottom_pt(self):
 213         """return bottom coordinate of bbox in pts"""
 214         return self.lly_pt
 215
 216     def left_pt(self):
 217         """return left coordinate of bbox in pts"""
 218         return self.llx_pt
 219
 220     def right_pt(self):
 221         """return right coordinate of bbox in pts"""
 222         return self.urx_pt
 223
 224     def center_pt(self):
 225         """return coordinates of the center of the bbox in pts"""
 226         return 0.5 * (self.llx_pt+self.urx_pt), 0.5 * (self.lly_pt+self.ury_pt)
 227
 228     def height(self):
 229         """return height of bbox"""
 230         return self.height_pt() * unit.t_pt
 231
 232     def width(self):
 233         """return width of bbox"""
 234         return self.width_pt() * unit.t_pt
 235
 236     def top(self):
 237         """return top coordinate of bbox"""
 238         return self.ury_pt * unit.t_pt
 239
 240     def bottom(self):
 241         """return bottom coordinate of bbox"""
 242         return self.lly_pt * unit.t_pt
 243
 244     def left(self):
 245         """return left coordinate of bbox"""
 246         return self.llx_pt * unit.t_pt
 247
 248     def right(self):
 249         """return right coordinate of bbox"""
 250         return self.urx_pt * unit.t_pt
 251
 252     def center(self):
 253         """return coordinates of the center of the bbox"""
 254         centerx_pt, centery_pt = self.center_pt()
 255         return centerx_pt * unit.t_pt, centery_pt * unit.t_pt
 256
 257
 258 class bbox(bbox_pt):
 259
 260     """class for bounding boxes"""
 261
 262     def __init__(self, llx_pt, lly_pt, urx_pt, ury_pt):
 263         llx_pt = unit.topt(llx_pt)
 264         lly_pt = unit.topt(lly_pt)
 265         urx_pt = unit.topt(urx_pt)
 266         ury_pt = unit.topt(ury_pt)
 267         bbox_pt.__init__(self, llx_pt, lly_pt, urx_pt, ury_pt)