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      1 # Copyright 2017 Google Inc.
      2 #
      3 # Use of this source code is governed by a BSD-style license that can be
      4 # found in the LICENSE file.
      5 
      6 """
      7 Visualize bitmaps in gdb.
      8 
      9 (gdb) source <path to this file>
     10 (gdb) sk_bitmap <symbol>
     11 
     12 This should pop up a window with the bitmap displayed.
     13 Right clicking should bring up a menu, allowing the
     14 bitmap to be saved to a file.
     15 """
     16 
     17 import gdb
     18 from enum import Enum
     19 try:
     20   from PIL import Image
     21 except ImportError:
     22   import Image
     23 
     24 class ColorType(Enum):
     25     unknown = 0
     26     alpha_8 = 1
     27     rgb_565 = 2
     28     argb_4444 = 3
     29     rgba_8888 = 4
     30     bgra_8888 = 5
     31     gray_8 = 6
     32     rgba_F16 = 7
     33 
     34 class AlphaType(Enum):
     35     unknown = 0
     36     opaque = 1
     37     premul = 2
     38     unpremul = 3
     39 
     40 class sk_bitmap(gdb.Command):
     41   """Displays the content of an SkBitmap image."""
     42 
     43   def __init__(self):
     44       super(sk_bitmap, self).__init__('sk_bitmap',
     45                                       gdb.COMMAND_SUPPORT,
     46                                       gdb.COMPLETE_FILENAME)
     47 
     48   def invoke(self, arg, from_tty):
     49     frame = gdb.selected_frame()
     50     val = frame.read_var(arg)
     51     if str(val.type.strip_typedefs()) == 'SkBitmap':
     52       pixels = val['fPixels']
     53       row_bytes = val['fRowBytes']
     54       info = val['fInfo']
     55       width = info['fWidth']
     56       height = info['fHeight']
     57       color_type = info['fColorType']
     58       alpha_type = info['fAlphaType']
     59 
     60       process = gdb.selected_inferior()
     61       memory_data = process.read_memory(pixels, row_bytes * height)
     62       size = (width, height)
     63       image = None
     64       # See Unpack.c for the values understood after the "raw" parameter.
     65       if color_type == ColorType.bgra_8888.value:
     66         if alpha_type == AlphaType.unpremul.value:
     67           image = Image.frombytes("RGBA", size, memory_data.tobytes(),
     68                                   "raw", "BGRA", row_bytes, 1)
     69         elif alpha_type == AlphaType.premul.value:
     70           # RGBA instead of RGBa, because Image.show() doesn't work with RGBa.
     71           image = Image.frombytes("RGBA", size, memory_data.tobytes(),
     72                                   "raw", "BGRa", row_bytes, 1)
     73 
     74       if image:
     75         # Fails on premultiplied alpha, it cannot convert to RGB.
     76         image.show()
     77       else:
     78         print ("Need to add support for %s %s." % (
     79                str(ColorType(int(color_type))),
     80                str(AlphaType(int(alpha_type)))
     81         ))
     82 
     83 sk_bitmap()
     84