Lib/plat-mac/PixMapWrapper.py

   1 """PixMapWrapper - defines the PixMapWrapper class, which wraps an opaque
   2 QuickDraw PixMap data structure in a handy Python class.  Also provides
   3 methods to convert to/from pixel data (from, e.g., the img module) or a
   4 Python Imaging Library Image object.
   5
   6 J. Strout <joe@strout.net>  February 1999"""
   7
   8 from Carbon import Qd
   9 from Carbon import QuickDraw
  10 import struct
  11 import MacOS
  12 import img
  13 import imgformat
  14
  15 # PixMap data structure element format (as used with struct)
  16 _pmElemFormat = {
  17     'baseAddr':'l',     # address of pixel data
  18     'rowBytes':'H',     # bytes per row, plus 0x8000
  19     'bounds':'hhhh',    # coordinates imposed over pixel data
  20         'top':'h',
  21         'left':'h',
  22         'bottom':'h',
  23         'right':'h',
  24     'pmVersion':'h',    # flags for Color QuickDraw
  25     'packType':'h',     # format of compression algorithm
  26     'packSize':'l',     # size after compression
  27     'hRes':'l',         # horizontal pixels per inch
  28     'vRes':'l',         # vertical pixels per inch
  29     'pixelType':'h',    # pixel format
  30     'pixelSize':'h',    # bits per pixel
  31     'cmpCount':'h',     # color components per pixel
  32     'cmpSize':'h',      # bits per component
  33     'planeBytes':'l',   # offset in bytes to next plane
  34     'pmTable':'l',      # handle to color table
  35     'pmReserved':'l'    # reserved for future use
  36 }
  37
  38 # PixMap data structure element offset
  39 _pmElemOffset = {
  40     'baseAddr':0,
  41     'rowBytes':4,
  42     'bounds':6,
  43         'top':6,
  44         'left':8,
  45         'bottom':10,
  46         'right':12,
  47     'pmVersion':14,
  48     'packType':16,
  49     'packSize':18,
  50     'hRes':22,
  51     'vRes':26,
  52     'pixelType':30,
  53     'pixelSize':32,
  54     'cmpCount':34,
  55     'cmpSize':36,
  56     'planeBytes':38,
  57     'pmTable':42,
  58     'pmReserved':46
  59 }
  60
  61 class PixMapWrapper:
  62     """PixMapWrapper -- wraps the QD PixMap object in a Python class,
  63     with methods to easily get/set various pixmap fields.  Note: Use the
  64     PixMap() method when passing to QD calls."""
  65
  66     def __init__(self):
  67         self.__dict__['data'] = ''
  68         self._header = struct.pack("lhhhhhhhlllhhhhlll",
  69             id(self.data)+MacOS.string_id_to_buffer,
  70             0,                      # rowBytes
  71             0, 0, 0, 0,             # bounds
  72             0,                      # pmVersion
  73             0, 0,                   # packType, packSize
  74             72<<16, 72<<16,         # hRes, vRes
  75             QuickDraw.RGBDirect,    # pixelType
  76             16,                     # pixelSize
  77             2, 5,                   # cmpCount, cmpSize,
  78             0, 0, 0)                # planeBytes, pmTable, pmReserved
  79         self.__dict__['_pm'] = Qd.RawBitMap(self._header)
  80
  81     def _stuff(self, element, bytes):
  82         offset = _pmElemOffset[element]
  83         fmt = _pmElemFormat[element]
  84         self._header = self._header[:offset] \
  85             + struct.pack(fmt, bytes) \
  86             + self._header[offset + struct.calcsize(fmt):]
  87         self.__dict__['_pm'] = None
  88
  89     def _unstuff(self, element):
  90         offset = _pmElemOffset[element]
  91         fmt = _pmElemFormat[element]
  92         return struct.unpack(fmt, self._header[offset:offset+struct.calcsize(fmt)])[0]
  93
  94     def __setattr__(self, attr, val):
  95         if attr == 'baseAddr':
  96             raise 'UseErr', "don't assign to .baseAddr -- assign to .data instead"
  97         elif attr == 'data':
  98             self.__dict__['data'] = val
  99             self._stuff('baseAddr', id(self.data) + MacOS.string_id_to_buffer)
 100         elif attr == 'rowBytes':
 101             # high bit is always set for some odd reason
 102             self._stuff('rowBytes', val | 0x8000)
 103         elif attr == 'bounds':
 104             # assume val is in official Left, Top, Right, Bottom order!
 105             self._stuff('left',val[0])
 106             self._stuff('top',val[1])
 107             self._stuff('right',val[2])
 108             self._stuff('bottom',val[3])
 109         elif attr == 'hRes' or attr == 'vRes':
 110             # 16.16 fixed format, so just shift 16 bits
 111             self._stuff(attr, int(val) << 16)
 112         elif attr in _pmElemFormat.keys():
 113             # any other pm attribute -- just stuff
 114             self._stuff(attr, val)
 115         else:
 116             self.__dict__[attr] = val
 117
 118     def __getattr__(self, attr):
 119         if attr == 'rowBytes':
 120             # high bit is always set for some odd reason
 121             return self._unstuff('rowBytes') & 0x7FFF
 122         elif attr == 'bounds':
 123             # return bounds in official Left, Top, Right, Bottom order!
 124             return ( \
 125                 self._unstuff('left'),
 126                 self._unstuff('top'),
 127                 self._unstuff('right'),
 128                 self._unstuff('bottom') )
 129         elif attr == 'hRes' or attr == 'vRes':
 130             # 16.16 fixed format, so just shift 16 bits
 131             return self._unstuff(attr) >> 16
 132         elif attr in _pmElemFormat.keys():
 133             # any other pm attribute -- just unstuff
 134             return self._unstuff(attr)
 135         else:
 136             return self.__dict__[attr]
 137
 138
 139     def PixMap(self):
 140         "Return a QuickDraw PixMap corresponding to this data."
 141         if not self.__dict__['_pm']:
 142             self.__dict__['_pm'] = Qd.RawBitMap(self._header)
 143         return self.__dict__['_pm']
 144
 145     def blit(self, x1=0,y1=0,x2=None,y2=None, port=None):
 146         """Draw this pixmap into the given (default current) grafport."""
 147         src = self.bounds
 148         dest = [x1,y1,x2,y2]
 149         if x2 == None:
 150             dest[2] = x1 + src[2]-src[0]
 151         if y2 == None:
 152             dest[3] = y1 + src[3]-src[1]
 153         if not port: port = Qd.GetPort()
 154         Qd.CopyBits(self.PixMap(), port.GetPortBitMapForCopyBits(), src, tuple(dest),
 155                 QuickDraw.srcCopy, None)
 156
 157     def fromstring(self,s,width,height,format=imgformat.macrgb):
 158         """Stuff this pixmap with raw pixel data from a string.
 159         Supply width, height, and one of the imgformat specifiers."""
 160         # we only support 16- and 32-bit mac rgb...
 161         # so convert if necessary
 162         if format != imgformat.macrgb and format != imgformat.macrgb16:
 163             # (LATER!)
 164             raise "NotImplementedError", "conversion to macrgb or macrgb16"
 165         self.data = s
 166         self.bounds = (0,0,width,height)
 167         self.cmpCount = 3
 168         self.pixelType = QuickDraw.RGBDirect
 169         if format == imgformat.macrgb:
 170             self.pixelSize = 32
 171             self.cmpSize = 8
 172         else:
 173             self.pixelSize = 16
 174             self.cmpSize = 5
 175         self.rowBytes = width*self.pixelSize/8
 176
 177     def tostring(self, format=imgformat.macrgb):
 178         """Return raw data as a string in the specified format."""
 179         # is the native format requested?  if so, just return data
 180         if (format == imgformat.macrgb and self.pixelSize == 32) or \
 181            (format == imgformat.macrgb16 and self.pixelsize == 16):
 182             return self.data
 183         # otherwise, convert to the requested format
 184         # (LATER!)
 185             raise "NotImplementedError", "data format conversion"
 186
 187     def fromImage(self,im):
 188         """Initialize this PixMap from a PIL Image object."""
 189         # We need data in ARGB format; PIL can't currently do that,
 190         # but it can do RGBA, which we can use by inserting one null
 191         # up frontpm =
 192         if im.mode != 'RGBA': im = im.convert('RGBA')
 193         data = chr(0) + im.tostring()
 194         self.fromstring(data, im.size[0], im.size[1])
 195
 196     def toImage(self):
 197         """Return the contents of this PixMap as a PIL Image object."""
 198         import Image
 199         # our tostring() method returns data in ARGB format,
 200         # whereas Image uses RGBA; a bit of slicing fixes this...
 201         data = self.tostring()[1:] + chr(0)
 202         bounds = self.bounds
 203         return Image.fromstring('RGBA',(bounds[2]-bounds[0],bounds[3]-bounds[1]),data)
 204
 205 def test():
 206     import MacOS
 207     import EasyDialogs
 208     import Image
 209     path = EasyDialogs.AskFileForOpen("Image File:")
 210     if not path: return
 211     pm = PixMapWrapper()
 212     pm.fromImage( Image.open(path) )
 213     pm.blit(20,20)
 214     return pm