Class around PixMap objects that allows more python-like access. By Joe Strout.

diff --git a/Mac/Lib/PixMapWrapper.py b/Mac/Lib/PixMapWrapper.py
new file mode 100644 (file)
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+++ b/Mac/Lib/PixMapWrapper.py
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+"""PixMapWrapper - defines the PixMapWrapper class, which wraps an opaque
+QuickDraw PixMap data structure in a handy Python class.  Also provides 
+methods to convert to/from pixel data (from, e.g., the img module) or a
+Python Imaging Library Image object.
+
+J. Strout <joe@strout.net>  February 1999"""
+
+import Qd
+import QuickDraw
+import struct
+import MacOS
+import img
+import imgformat
+
+# PixMap data structure element format (as used with struct)
+_pmElemFormat = {
+       'baseAddr':'l',         # address of pixel data
+       'rowBytes':'h',         # bytes per row, plus 0x8000
+       'bounds':'hhhh',        # coordinates imposed over pixel data
+               'top':'h',
+               'left':'h',
+               'bottom':'h',
+               'right':'h',
+       'pmVersion':'h',        # flags for Color QuickDraw
+       'packType':'h',         # format of compression algorithm
+       'packSize':'l',         # size after compression
+       'hRes':'l',                     # horizontal pixels per inch
+       'vRes':'l',                     # vertical pixels per inch
+       'pixelType':'h',        # pixel format
+       'pixelSize':'h',        # bits per pixel
+       'cmpCount':'h',         # color components per pixel
+       'cmpSize':'h',          # bits per component
+       'planeBytes':'l',       # offset in bytes to next plane
+       'pmTable':'l',          # handle to color table
+       'pmReserved':'l'        # reserved for future use
+}
+
+# PixMap data structure element offset
+_pmElemOffset = {
+       'baseAddr':0,
+       'rowBytes':4,
+       'bounds':6,
+               'top':6,
+               'left':8,
+               'bottom':10,
+               'right':12,
+       'pmVersion':14,
+       'packType':16,
+       'packSize':18,
+       'hRes':22,
+       'vRes':26,
+       'pixelType':30,
+       'pixelSize':32,
+       'cmpCount':34,
+       'cmpSize':36,
+       'planeBytes':38,
+       'pmTable':42,
+       'pmReserved':46
+}
+
+class PixMapWrapper:
+       """PixMapWrapper -- wraps the QD PixMap object in a Python class,
+       with methods to easily get/set various pixmap fields.  Note: Use the
+       PixMap() method when passing to QD calls."""
+
+       def __init__(self):
+               self.__dict__['data'] = ''
+               self._header = struct.pack("lhhhhhhhlllhhhhlll",
+                       id(self.data)+MacOS.string_id_to_buffer,
+                       0,                                              # rowBytes
+                       0, 0, 0, 0,                             # bounds
+                       0,                                              # pmVersion
+                       0, 0,                                   # packType, packSize
+                       72<<16, 72<<16,                 # hRes, vRes
+                       QuickDraw.RGBDirect,    # pixelType
+                       16,                                             # pixelSize
+                       2, 5,                                   # cmpCount, cmpSize,
+                       0, 0, 0)                                # planeBytes, pmTable, pmReserved
+               self.__dict__['_pm'] = Qd.RawBitMap(self._header)
+       
+       def _stuff(self, element, bytes):
+               offset = _pmElemOffset[element]
+               fmt = _pmElemFormat[element]
+               self._header = self._header[:offset] \
+                       + struct.pack(fmt, bytes) \
+                       + self._header[offset + struct.calcsize(fmt):]
+               self.__dict__['_pm'] = None
+       
+       def _unstuff(self, element):
+               offset = _pmElemOffset[element]
+               fmt = _pmElemFormat[element]
+               return struct.unpack(fmt, self._header[offset:offset+struct.calcsize(fmt)])[0]
+
+       def __setattr__(self, attr, val):
+               if attr == 'baseAddr':
+                       raise 'UseErr', "don't assign to .baseAddr -- assign to .data instead"
+               elif attr == 'data':
+                       self.__dict__['data'] = val
+                       self._stuff('baseAddr', id(self.data) + MacOS.string_id_to_buffer)
+               elif attr == 'rowBytes':
+                       # high bit is always set for some odd reason
+                       self._stuff('rowBytes', val | 0x8000)
+               elif attr == 'bounds':
+                       # assume val is in official Left, Top, Right, Bottom order!
+                       self._stuff('left',val[0])
+                       self._stuff('top',val[1])
+                       self._stuff('right',val[2])
+                       self._stuff('bottom',val[3])
+               elif attr == 'hRes' or attr == 'vRes':
+                       # 16.16 fixed format, so just shift 16 bits
+                       self._stuff(attr, int(val) << 16)
+               elif attr in _pmElemFormat.keys():
+                       # any other pm attribute -- just stuff
+                       self._stuff(attr, val)
+               else:
+                       self.__dict__[attr] = val       
+
+       def __getattr__(self, attr):
+               if attr == 'rowBytes':
+                       # high bit is always set for some odd reason
+                       return self._unstuff('rowBytes') & 0x7FFF
+               elif attr == 'bounds':
+                       # return bounds in official Left, Top, Right, Bottom order!
+                       return ( \
+                               self._unstuff('left'),
+                               self._unstuff('top'),
+                               self._unstuff('right'),
+                               self._unstuff('bottom') )
+               elif attr == 'hRes' or attr == 'vRes':
+                       # 16.16 fixed format, so just shift 16 bits
+                       return self._unstuff(attr) >> 16
+               elif attr in _pmElemFormat.keys():
+                       # any other pm attribute -- just unstuff
+                       return self._unstuff(attr)
+               else:
+                       return self.__dict__[attr]      
+
+               
+       def PixMap(self):
+               "Return a QuickDraw PixMap corresponding to this data."
+               if not self.__dict__['_pm']:
+                       self.__dict__['_pm'] = Qd.RawBitMap(self._header)
+               return self.__dict__['_pm']
+
+       def blit(self, x1=0,y1=0,x2=None,y2=None, port=None):
+               """Draw this pixmap into the given (default current) grafport.""" 
+               src = self.bounds
+               dest = [x1,y1,x2,y2]
+               if x2 == None:
+                       dest[2] = x1 + src[2]-src[0]
+               if y2 == None:
+                       dest[3] = y1 + src[3]-src[1]
+               if not port: port = Qd.GetPort()
+               Qd.CopyBits(self.PixMap(), port.portBits, src, tuple(dest),
+                               QuickDraw.srcCopy, None)
+       
+       def fromstring(self,s,width,height,format=imgformat.macrgb):
+               """Stuff this pixmap with raw pixel data from a string.
+               Supply width, height, and one of the imgformat specifiers."""
+               # we only support 16- and 32-bit mac rgb...
+               # so convert if necessary
+               if format != imgformat.macrgb and format != imgformat.macrgb16:
+                       # (LATER!)
+                       raise "NotImplementedError", "conversion to macrgb or macrgb16"
+               self.data = s
+               self.bounds = (0,0,width,height)
+               self.cmpCount = 3
+               self.pixelType = QuickDraw.RGBDirect
+               if format == imgformat.macrgb:
+                       self.pixelSize = 32
+                       self.cmpSize = 8
+               else:
+                       self.pixelSize = 16
+                       self.cmpSize = 5
+               self.rowBytes = width*self.pixelSize/8
+
+       def tostring(self, format=imgformat.macrgb):
+               """Return raw data as a string in the specified format."""
+               # is the native format requested?  if so, just return data
+               if (format == imgformat.macrgb and self.pixelSize == 32) or \
+                  (format == imgformat.macrgb16 and self.pixelsize == 16):
+                       return self.data
+               # otherwise, convert to the requested format
+               # (LATER!)
+                       raise "NotImplementedError", "data format conversion"
+
+       def fromImage(self,im):
+               """Initialize this PixMap from a PIL Image object."""
+               # We need data in ARGB format; PIL can't currently do that,
+               # but it can do RGBA, which we can use by inserting one null
+               # up frontpm = 
+               if im.mode != 'RGBA': im = im.convert('RGBA')
+               data = chr(0) + im.tostring()
+               self.fromstring(data, im.size[0], im.size[1])
+
+       def toImage(self):
+               """Return the contents of this PixMap as a PIL Image object."""
+               import Image
+               # our tostring() method returns data in ARGB format,
+               # whereas Image uses RGBA; a bit of slicing fixes this...
+               data = self.tostring()[1:] + chr(0)
+               bounds = self.bounds
+               return Image.fromstring('RGBA',(bounds[2]-bounds[0],bounds[3]-bounds[1]),data)
+
+def test():
+       import MacOS
+       import macfs
+       import Image
+       fsspec, ok = macfs.PromptGetFile("Image File:")
+       if not ok: return
+       path = fsspec.as_pathname()
+       pm = PixMapWrapper()
+       pm.fromImage( Image.open(path) )
+       pm.blit(20,20)
+       return pm
+