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(self, all=0, bottom=None, left=None, top=None, right=None):
 122         """enlarge bbox in place
 123
 124         all is used, if bottom, left, top and/or right are not given.
 125
 126         """
 127         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 128         if bottom is not None:
 129            bottom_pt = unit.topt(bottom)
 130         if left is not None:
 131            left_pt = unit.topt(left)
 132         if top is not None:
 133            top_pt = unit.topt(top)
 134         if right is not None:
 135            right_pt = unit.topt(right)
 136         self.llx_pt -= left_pt
 137         self.lly_pt -= bottom_pt
 138         self.urx_pt += right_pt
 139         self.ury_pt += top_pt
 140
 141     def enlarged(self, all=0, bottom=None, left=None, top=None, right=None):
 142         """return bbox enlarged
 143
 144         all is used, if bottom, left, top and/or right are not given.
 145
 146         """
 147         bottom_pt = left_pt = top_pt = right_pt = unit.topt(all)
 148         if bottom is not None:
 149            bottom_pt = unit.topt(bottom)
 150         if left is not None:
 151            left_pt = unit.topt(left)
 152         if top is not None:
 153            top_pt = unit.topt(top)
 154         if right is not None:
 155            right_pt = unit.topt(right)
 156         return bbox_pt(self.llx_pt-left_pt, self.lly_pt-bottom_pt, self.urx_pt+right_pt, self.ury_pt+top_pt)
 157
 158     def rect(self):
 159         """return rectangle corresponding to bbox"""
 160         import path
 161         return path.rect_pt(self.llx_pt, self.lly_pt, self.urx_pt-self.llx_pt, self.ury_pt-self.lly_pt)
 162
 163     path = rect
 164
 165     def height_pt(self):
 166         """return height of bbox in pts"""
 167         return self.ury_pt-self.lly_pt
 168
 169     def width_pt(self):
 170         """return width of bbox in pts"""
 171         return self.urx_pt-self.llx_pt
 172
 173     def top_pt(self):
 174         """return top coordinate of bbox in pts"""
 175         return self.ury_pt
 176
 177     def bottom_pt(self):
 178         """return bottom coordinate of bbox in pts"""
 179         return self.lly_pt
 180
 181     def left_pt(self):
 182         """return left coordinate of bbox in pts"""
 183         return self.llx_pt
 184
 185     def right_pt(self):
 186         """return right coordinate of bbox in pts"""
 187         return self.urx_pt
 188
 189     def center_pt(self):
 190         """return coordinates of the center of the bbox in pts"""
 191         return 0.5 * (self.llx_pt+self.urx_pt), 0.5 * (self.lly_pt+self.ury_pt)
 192
 193     def height(self):
 194         """return height of bbox"""
 195         return self.height_pt() * unit.t_pt
 196
 197     def width(self):
 198         """return width of bbox"""
 199         return self.width_pt() * unit.t_pt
 200
 201     def top(self):
 202         """return top coordinate of bbox"""
 203         return self.ury_pt * unit.t_pt
 204
 205     def bottom(self):
 206         """return bottom coordinate of bbox"""
 207         return self.lly_pt * unit.t_pt
 208
 209     def left(self):
 210         """return left coordinate of bbox"""
 211         return self.llx_pt * unit.t_pt
 212
 213     def right(self):
 214         """return right coordinate of bbox"""
 215         return self.urx_pt * unit.t_pt
 216
 217     def center(self):
 218         """return coordinates of the center of the bbox"""
 219         centerx_pt, centery_pt = self.center_pt()
 220         return centerx_pt * unit.t_pt, centery_pt * unit.t_pt
 221
 222
 223 class bbox(bbox_pt):
 224
 225     """class for bounding boxes"""
 226
 227     def __init__(self, llx_pt, lly_pt, urx_pt, ury_pt):
 228         llx_pt = unit.topt(llx_pt)
 229         lly_pt = unit.topt(lly_pt)
 230         urx_pt = unit.topt(urx_pt)
 231         ury_pt = unit.topt(ury_pt)
 232         bbox_pt.__init__(self, llx_pt, lly_pt, urx_pt, ury_pt)