/Lib/plat-mac/PixMapWrapper.py

  1"""PixMapWrapper - defines the PixMapWrapper class, which wraps an opaque
  2QuickDraw PixMap data structure in a handy Python class.  Also provides
  3methods to convert to/from pixel data (from, e.g., the img module) or a
  4Python Imaging Library Image object.
  5
  6J. Strout <joe@strout.net>  February 1999"""
  7
  8
  9from warnings import warnpy3k
 10warnpy3k("In 3.x, the PixMapWrapper module is removed.", stacklevel=2)
 11
 12from Carbon import Qd
 13from Carbon import QuickDraw
 14import struct
 15import MacOS
 16import img
 17import imgformat
 18
 19# PixMap data structure element format (as used with struct)
 20_pmElemFormat = {
 21    'baseAddr':'l',     # address of pixel data
 22    'rowBytes':'H',     # bytes per row, plus 0x8000
 23    'bounds':'hhhh',    # coordinates imposed over pixel data
 24        'top':'h',
 25        'left':'h',
 26        'bottom':'h',
 27        'right':'h',
 28    'pmVersion':'h',    # flags for Color QuickDraw
 29    'packType':'h',     # format of compression algorithm
 30    'packSize':'l',     # size after compression
 31    'hRes':'l',         # horizontal pixels per inch
 32    'vRes':'l',         # vertical pixels per inch
 33    'pixelType':'h',    # pixel format
 34    'pixelSize':'h',    # bits per pixel
 35    'cmpCount':'h',     # color components per pixel
 36    'cmpSize':'h',      # bits per component
 37    'planeBytes':'l',   # offset in bytes to next plane
 38    'pmTable':'l',      # handle to color table
 39    'pmReserved':'l'    # reserved for future use
 40}
 41
 42# PixMap data structure element offset
 43_pmElemOffset = {
 44    'baseAddr':0,
 45    'rowBytes':4,
 46    'bounds':6,
 47        'top':6,
 48        'left':8,
 49        'bottom':10,
 50        'right':12,
 51    'pmVersion':14,
 52    'packType':16,
 53    'packSize':18,
 54    'hRes':22,
 55    'vRes':26,
 56    'pixelType':30,
 57    'pixelSize':32,
 58    'cmpCount':34,
 59    'cmpSize':36,
 60    'planeBytes':38,
 61    'pmTable':42,
 62    'pmReserved':46
 63}
 64
 65class PixMapWrapper:
 66    """PixMapWrapper -- wraps the QD PixMap object in a Python class,
 67    with methods to easily get/set various pixmap fields.  Note: Use the
 68    PixMap() method when passing to QD calls."""
 69
 70    def __init__(self):
 71        self.__dict__['data'] = ''
 72        self._header = struct.pack("lhhhhhhhlllhhhhlll",
 73            id(self.data)+MacOS.string_id_to_buffer,
 74            0,                      # rowBytes
 75            0, 0, 0, 0,             # bounds
 76            0,                      # pmVersion
 77            0, 0,                   # packType, packSize
 78            72<<16, 72<<16,         # hRes, vRes
 79            QuickDraw.RGBDirect,    # pixelType
 80            16,                     # pixelSize
 81            2, 5,                   # cmpCount, cmpSize,
 82            0, 0, 0)                # planeBytes, pmTable, pmReserved
 83        self.__dict__['_pm'] = Qd.RawBitMap(self._header)
 84
 85    def _stuff(self, element, bytes):
 86        offset = _pmElemOffset[element]
 87        fmt = _pmElemFormat[element]
 88        self._header = self._header[:offset] \
 89            + struct.pack(fmt, bytes) \
 90            + self._header[offset + struct.calcsize(fmt):]
 91        self.__dict__['_pm'] = None
 92
 93    def _unstuff(self, element):
 94        offset = _pmElemOffset[element]
 95        fmt = _pmElemFormat[element]
 96        return struct.unpack(fmt, self._header[offset:offset+struct.calcsize(fmt)])[0]
 97
 98    def __setattr__(self, attr, val):
 99        if attr == 'baseAddr':
100            raise 'UseErr', "don't assign to .baseAddr -- assign to .data instead"
101        elif attr == 'data':
102            self.__dict__['data'] = val
103            self._stuff('baseAddr', id(self.data) + MacOS.string_id_to_buffer)
104        elif attr == 'rowBytes':
105            # high bit is always set for some odd reason
106            self._stuff('rowBytes', val | 0x8000)
107        elif attr == 'bounds':
108            # assume val is in official Left, Top, Right, Bottom order!
109            self._stuff('left',val[0])
110            self._stuff('top',val[1])
111            self._stuff('right',val[2])
112            self._stuff('bottom',val[3])
113        elif attr == 'hRes' or attr == 'vRes':
114            # 16.16 fixed format, so just shift 16 bits
115            self._stuff(attr, int(val) << 16)
116        elif attr in _pmElemFormat.keys():
117            # any other pm attribute -- just stuff
118            self._stuff(attr, val)
119        else:
120            self.__dict__[attr] = val
121
122    def __getattr__(self, attr):
123        if attr == 'rowBytes':
124            # high bit is always set for some odd reason
125            return self._unstuff('rowBytes') & 0x7FFF
126        elif attr == 'bounds':
127            # return bounds in official Left, Top, Right, Bottom order!
128            return ( \
129                self._unstuff('left'),
130                self._unstuff('top'),
131                self._unstuff('right'),
132                self._unstuff('bottom') )
133        elif attr == 'hRes' or attr == 'vRes':
134            # 16.16 fixed format, so just shift 16 bits
135            return self._unstuff(attr) >> 16
136        elif attr in _pmElemFormat.keys():
137            # any other pm attribute -- just unstuff
138            return self._unstuff(attr)
139        else:
140            return self.__dict__[attr]
141
142
143    def PixMap(self):
144        "Return a QuickDraw PixMap corresponding to this data."
145        if not self.__dict__['_pm']:
146            self.__dict__['_pm'] = Qd.RawBitMap(self._header)
147        return self.__dict__['_pm']
148
149    def blit(self, x1=0,y1=0,x2=None,y2=None, port=None):
150        """Draw this pixmap into the given (default current) grafport."""
151        src = self.bounds
152        dest = [x1,y1,x2,y2]
153        if x2 is None:
154            dest[2] = x1 + src[2]-src[0]
155        if y2 is None:
156            dest[3] = y1 + src[3]-src[1]
157        if not port: port = Qd.GetPort()
158        Qd.CopyBits(self.PixMap(), port.GetPortBitMapForCopyBits(), src, tuple(dest),
159                QuickDraw.srcCopy, None)
160
161    def fromstring(self,s,width,height,format=imgformat.macrgb):
162        """Stuff this pixmap with raw pixel data from a string.
163        Supply width, height, and one of the imgformat specifiers."""
164        # we only support 16- and 32-bit mac rgb...
165        # so convert if necessary
166        if format != imgformat.macrgb and format != imgformat.macrgb16:
167            # (LATER!)
168            raise "NotImplementedError", "conversion to macrgb or macrgb16"
169        self.data = s
170        self.bounds = (0,0,width,height)
171        self.cmpCount = 3
172        self.pixelType = QuickDraw.RGBDirect
173        if format == imgformat.macrgb:
174            self.pixelSize = 32
175            self.cmpSize = 8
176        else:
177            self.pixelSize = 16
178            self.cmpSize = 5
179        self.rowBytes = width*self.pixelSize/8
180
181    def tostring(self, format=imgformat.macrgb):
182        """Return raw data as a string in the specified format."""
183        # is the native format requested?  if so, just return data
184        if (format == imgformat.macrgb and self.pixelSize == 32) or \
185           (format == imgformat.macrgb16 and self.pixelsize == 16):
186            return self.data
187        # otherwise, convert to the requested format
188        # (LATER!)
189            raise "NotImplementedError", "data format conversion"
190
191    def fromImage(self,im):
192        """Initialize this PixMap from a PIL Image object."""
193        # We need data in ARGB format; PIL can't currently do that,
194        # but it can do RGBA, which we can use by inserting one null
195        # up frontpm =
196        if im.mode != 'RGBA': im = im.convert('RGBA')
197        data = chr(0) + im.tostring()
198        self.fromstring(data, im.size[0], im.size[1])
199
200    def toImage(self):
201        """Return the contents of this PixMap as a PIL Image object."""
202        import Image
203        # our tostring() method returns data in ARGB format,
204        # whereas Image uses RGBA; a bit of slicing fixes this...
205        data = self.tostring()[1:] + chr(0)
206        bounds = self.bounds
207        return Image.fromstring('RGBA',(bounds[2]-bounds[0],bounds[3]-bounds[1]),data)
208
209def test():
210    import MacOS
211    import EasyDialogs
212    import Image
213    path = EasyDialogs.AskFileForOpen("Image File:")
214    if not path: return
215    pm = PixMapWrapper()
216    pm.fromImage( Image.open(path) )
217    pm.blit(20,20)
218    return pm