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https://github.com/kovidgoyal/calibre.git
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Fix cmap table generation not handling contiguous indices
Also fix tab indentation in code imported from fonttools.
This commit is contained in:
Kovid Goyal
parent
46ed78b892
commit
85d09338d7
@ -17,85 +17,85 @@ from calibre.utils.fonts.utils import read_bmp_prefix
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from calibre.utils.fonts.sfnt import UnknownTable, max_power_of_two
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from calibre.utils.fonts.sfnt.errors import UnsupportedFont
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def split_range(start_code, end_code, cmap): # {{{
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# Try to split a range of character codes into subranges with consecutive
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# glyph IDs in such a way that the cmap4 subtable can be stored "most"
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# efficiently.
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if start_code == end_code:
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return [], [end_code]
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def split_range(start_code, end_code, cmap): # {{{
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# Try to split a range of character codes into subranges with consecutive
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# glyph IDs in such a way that the cmap4 subtable can be stored "most"
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# efficiently.
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if start_code == end_code:
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return [], [end_code]
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last_id = cmap[start_code]
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last_code = start_code
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in_order = None
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ordered_begin = None
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sub_ranges = []
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last_id = cmap[start_code]
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last_code = start_code
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in_order = None
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ordered_begin = None
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sub_ranges = []
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# Gather subranges in which the glyph IDs are consecutive.
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for code in range(start_code + 1, end_code + 1):
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glyph_id = cmap[code]
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# Gather subranges in which the glyph IDs are consecutive.
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for code in range(start_code + 1, end_code + 1):
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glyph_id = cmap[code]
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if glyph_id - 1 == last_id:
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if in_order is None or not in_order:
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in_order = 1
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ordered_begin = last_code
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else:
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if in_order:
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in_order = 0
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sub_ranges.append((ordered_begin, last_code))
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ordered_begin = None
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if glyph_id - 1 == last_id:
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if in_order is None or not in_order:
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in_order = 1
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ordered_begin = last_code
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else:
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if in_order:
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in_order = 0
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sub_ranges.append((ordered_begin, last_code))
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ordered_begin = None
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last_id = glyph_id
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last_code = code
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last_id = glyph_id
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last_code = code
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if in_order:
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sub_ranges.append((ordered_begin, last_code))
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assert last_code == end_code
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if in_order:
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sub_ranges.append((ordered_begin, last_code))
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assert last_code == end_code
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# Now filter out those new subranges that would only make the data bigger.
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# A new segment cost 8 bytes, not using a new segment costs 2 bytes per
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# character.
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new_ranges = []
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for b, e in sub_ranges:
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if b == start_code and e == end_code:
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break # the whole range, we're fine
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if b == start_code or e == end_code:
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threshold = 4 # split costs one more segment
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else:
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threshold = 8 # split costs two more segments
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if (e - b + 1) > threshold:
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new_ranges.append((b, e))
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sub_ranges = new_ranges
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# Now filter out those new subranges that would only make the data bigger.
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# A new segment cost 8 bytes, not using a new segment costs 2 bytes per
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# character.
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new_ranges = []
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for b, e in sub_ranges:
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if b == start_code and e == end_code:
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break # the whole range, we're fine
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if b == start_code or e == end_code:
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threshold = 4 # split costs one more segment
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else:
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threshold = 8 # split costs two more segments
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if (e - b + 1) > threshold:
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new_ranges.append((b, e))
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sub_ranges = new_ranges
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if not sub_ranges:
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return [], [end_code]
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if not sub_ranges:
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return [], [end_code]
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if sub_ranges[0][0] != start_code:
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sub_ranges.insert(0, (start_code, sub_ranges[0][0] - 1))
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if sub_ranges[-1][1] != end_code:
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sub_ranges.append((sub_ranges[-1][1] + 1, end_code))
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if sub_ranges[0][0] != start_code:
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sub_ranges.insert(0, (start_code, sub_ranges[0][0] - 1))
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if sub_ranges[-1][1] != end_code:
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sub_ranges.append((sub_ranges[-1][1] + 1, end_code))
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# Fill the "holes" in the segments list -- those are the segments in which
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# the glyph IDs are _not_ consecutive.
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i = 1
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while i < len(sub_ranges):
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if sub_ranges[i-1][1] + 1 != sub_ranges[i][0]:
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sub_ranges.insert(i, (sub_ranges[i-1][1] + 1, sub_ranges[i][0] - 1))
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i = i + 1
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i = i + 1
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# Fill the "holes" in the segments list -- those are the segments in which
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# the glyph IDs are _not_ consecutive.
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i = 1
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while i < len(sub_ranges):
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if sub_ranges[i-1][1] + 1 != sub_ranges[i][0]:
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sub_ranges.insert(i, (sub_ranges[i-1][1] + 1, sub_ranges[i][0] - 1))
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i = i + 1
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i = i + 1
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# Transform the ranges into start_code/end_code lists.
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start = []
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end = []
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for b, e in sub_ranges:
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start.append(b)
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end.append(e)
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start.pop(0)
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# Transform the ranges into start_code/end_code lists.
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start = []
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end = []
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for b, e in sub_ranges:
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start.append(b)
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end.append(e)
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start.pop(0)
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assert len(start) + 1 == len(end)
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return start, end
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assert len(start) + 1 == len(end)
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return start, end
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# }}}
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def set_id_delta(id_delta): # {{{
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def set_id_delta(id_delta): # {{{
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# The lowest gid in glyphIndexArray, after subtracting id_delta, must be 1.
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# id_delta is a short, and must be between -32K and 32K
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# startCode can be between 0 and 64K-1, and the first glyph index can be between 1 and 64K-1
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@ -237,57 +237,53 @@ class CmapTable(UnknownTable):
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start_code = [last_code]
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for code in codes[1:]:
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if code == last_code + 1:
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last_code = code
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continue
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start, end = split_range(start_code[-1], last_code, cmap)
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start_code.extend(start)
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end_code.extend(end)
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start_code.append(code)
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last_code = code
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end_code.append(last_code)
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start_code.append(0xffff)
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end_code.append(0xffff)
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if code == last_code + 1:
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last_code = code
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continue
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start, end = split_range(start_code[-1], last_code, cmap)
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start_code.extend(start)
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end_code.extend(end)
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start_code.append(code)
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last_code = code
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end_code.append(last_code)
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start_code.append(0xffff)
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end_code.append(0xffff)
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id_delta = []
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id_range_offset = []
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glyph_index_array = []
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for i in xrange(len(end_code)-1): # skip the closing codes (0xffff)
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indices = []
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for char_code in xrange(start_code[i], end_code[i] + 1):
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indices.append(cmap[char_code])
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if (indices == xrange(indices[0], indices[0] + len(indices))):
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id_delta_temp = set_id_delta(indices[0] - start_code[i])
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id_delta.append(id_delta_temp)
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id_range_offset.append(0)
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else:
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id_delta.append(0)
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id_range_offset.append(2 * (len(end_code) +
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len(glyph_index_array) - i))
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glyph_index_array.extend(indices)
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id_delta.append(1) # 0xffff + 1 == 0. So this end code maps to .notdef
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id_range_offset.append(0)
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id_delta = []
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id_range_offset = []
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glyph_index_array = []
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for i in xrange(len(end_code)-1): # skip the closing codes (0xffff)
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indices = list(cmap[char_code] for char_code in xrange(start_code[i], end_code[i] + 1))
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if indices == list(xrange(indices[0], indices[0] + len(indices))):
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# indices is a contiguous list
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id_delta_temp = set_id_delta(indices[0] - start_code[i])
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id_delta.append(id_delta_temp)
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id_range_offset.append(0)
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else:
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id_delta.append(0)
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id_range_offset.append(2 * (len(end_code) + len(glyph_index_array) - i))
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glyph_index_array.extend(indices)
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id_delta.append(1) # 0xffff + 1 == 0. So this end code maps to .notdef
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id_range_offset.append(0)
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seg_count = len(end_code)
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max_exponent = max_power_of_two(seg_count)
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search_range = 2 * (2 ** max_exponent)
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entry_selector = max_exponent
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range_shift = 2 * seg_count - search_range
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seg_count = len(end_code)
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max_exponent = max_power_of_two(seg_count)
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search_range = 2 * (2 ** max_exponent)
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entry_selector = max_exponent
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range_shift = 2 * seg_count - search_range
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char_code_array = end_code + [0] + start_code
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char_code_array = pack(b'>%dH'%len(char_code_array), *char_code_array)
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id_delta_array = pack(b'>%dh'%len(id_delta), *id_delta)
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char_code_array = pack(b'>%dH'%len(char_code_array), *char_code_array)
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id_delta_array = pack(b'>%dh'%len(id_delta), *id_delta)
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rest_array = id_range_offset + glyph_index_array
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rest_array = pack(b'>%dH'%len(rest_array), *rest_array)
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data = char_code_array + id_delta_array + rest_array
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data = char_code_array + id_delta_array + rest_array
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length = calcsize(fmt) + len(data)
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header = pack(fmt, 4, length, 0,
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2*seg_count, search_range, entry_selector, range_shift)
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self.bmp_table = header + data
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length = calcsize(fmt) + len(data)
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header = pack(fmt, 4, length, 0, 2*seg_count, search_range, entry_selector, range_shift)
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self.bmp_table = header + data
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fmt = b'>4HL'
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offset = calcsize(fmt)
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self.raw = pack(fmt, self.version, self.num_tables, 3, 1, offset) + \
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self.bmp_table
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self.raw = pack(fmt, self.version, self.num_tables, 3, 1, offset) + self.bmp_table
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