hachoir_parser/misc/pcf.py

"""
X11 Portable Compiled Font (pcf) parser.

Documents:
- Format for X11 pcf bitmap font files
  http://fontforge.sourceforge.net/pcf-format.html
  (file is based on the X11 sources)

Author: Victor Stinner
Creation date: 2007-03-20
"""

from hachoir_parser import Parser
from hachoir_core.field import (FieldSet, Enum,
    UInt8, UInt32, Bytes, RawBytes, NullBytes,
    Bit, Bits, PaddingBits, CString)
from hachoir_core.endian import LITTLE_ENDIAN, BIG_ENDIAN
from hachoir_core.text_handler import textHandler, hexadecimal, filesizeHandler
from hachoir_core.tools import paddingSize

class TOC(FieldSet):
    TYPE_NAME = {
        0x00000001: "Properties",
        0x00000002: "Accelerators",
        0x00000004: "Metrics",
        0x00000008: "Bitmaps",
        0x00000010: "Ink metrics",
        0x00000020: "BDF encodings",
        0x00000040: "SWidths",
        0x00000080: "Glyph names",
        0x00000100: "BDF accelerators",
    }

    FORMAT_NAME = {
        0x00000000: "Default",
        0x00000200: "Ink bounds",
        0x00000100: "Accelerator W ink bounds",
#        0x00000200: "Compressed metrics",
    }

    def createFields(self):
        yield Enum(UInt32(self, "type"), self.TYPE_NAME)
        yield UInt32(self, "format")
        yield filesizeHandler(UInt32(self, "size"))
        yield UInt32(self, "offset")

    def createDescription(self):
        return "%s at %s (%s)" % (
            self["type"].display, self["offset"].value, self["size"].display)

class PropertiesFormat(FieldSet):
    static_size = 32
    endian = LITTLE_ENDIAN
    def createFields(self):
        yield Bits(self, "reserved[]", 2)
        yield Bit(self, "byte_big_endian")
        yield Bit(self, "bit_big_endian")
        yield Bits(self, "scan_unit", 2)
        yield textHandler(PaddingBits(self, "reserved[]", 26), hexadecimal)

class Property(FieldSet):
    def createFields(self):
        yield UInt32(self, "name_offset")
        yield UInt8(self, "is_string")
        yield UInt32(self, "value_offset")

    def createDescription(self):
        # FIXME: Use link or any better way to read name value
        name = self["../name[%s]" % (self.index-2)].value
        return "Property %s" % name

class GlyphNames(FieldSet):
    def __init__(self, parent, name, toc, description, size=None):
        FieldSet.__init__(self, parent, name, description, size=size)
        self.toc = toc
        if self["format/byte_big_endian"].value:
            self.endian = BIG_ENDIAN
        else:
            self.endian = LITTLE_ENDIAN

    def createFields(self):
        yield PropertiesFormat(self, "format")
        yield UInt32(self, "count")
        offsets = []
        for index in xrange(self["count"].value):
            offset = UInt32(self, "offset[]")
            yield offset
            offsets.append(offset.value)
        yield UInt32(self, "total_str_length")
        offsets.sort()
        offset0 = self.current_size // 8
        for offset in offsets:
            padding = self.seekByte(offset0+offset)
            if padding:
                yield padding
            yield CString(self, "name[]")
        padding = (self.size - self.current_size) // 8
        if padding:
            yield NullBytes(self, "end_padding", padding)

class Properties(GlyphNames):
    def createFields(self):
        yield PropertiesFormat(self, "format")
        yield UInt32(self, "nb_prop")
        properties = []
        for index in xrange(self["nb_prop"].value):
            property = Property(self, "property[]")
            yield property
            properties.append(property)
        padding = paddingSize(self.current_size//8, 4)
        if padding:
            yield NullBytes(self, "padding", padding)
        yield UInt32(self, "total_str_length")
        properties.sort(key=lambda entry: entry["name_offset"].value)
        offset0 = self.current_size // 8
        for property in properties:
            padding = self.seekByte(offset0+property["name_offset"].value)
            if padding:
                yield padding
            yield CString(self, "name[]", "Name of %s" % property.name)
            if property["is_string"].value:
                yield CString(self, "value[]", "Value of %s" % property.name)
        padding = (self.size - self.current_size) // 8
        if padding:
            yield NullBytes(self, "end_padding", padding)

class PcfFile(Parser):
    MAGIC = "\1fcp"
    PARSER_TAGS = {
        "id": "pcf",
        "category": "misc",
        "file_ext": ("pcf",),
        "magic": ((MAGIC, 0),),
        "min_size": 32, # FIXME
        "description": "X11 Portable Compiled Font (pcf)",
    }
    endian = LITTLE_ENDIAN

    def validate(self):
        if self["signature"].value != self.MAGIC:
            return "Invalid signature"
        return True

    def createFields(self):
        yield Bytes(self, "signature", 4, r'File signature ("\1pcf")')
        yield UInt32(self, "nb_toc")
        entries = []
        for index in xrange(self["nb_toc"].value):
            entry = TOC(self, "toc[]")
            yield entry
            entries.append(entry)
        entries.sort(key=lambda entry: entry["offset"].value)
        for entry in entries:
            size = entry["size"].value
            padding = self.seekByte(entry["offset"].value)
            if padding:
                yield padding
            maxsize = (self.size-self.current_size)//8
            if maxsize < size:
                self.warning("Truncate content of %s to %s bytes (was %s)" % (entry.path, maxsize, size))
                size = maxsize
            if not size:
                continue
            if entry["type"].value == 1:
                yield Properties(self, "properties", entry, "Properties", size=size*8)
            elif entry["type"].value == 128:
                yield GlyphNames(self, "glyph_names", entry, "Glyph names", size=size*8)
            else:
                yield RawBytes(self, "data[]", size, "Content of %s" % entry.path)
hachoir-parser documentation built on Sept. 20, 2017, 5:30 p.m.