Variable: w32-no-usb-subranges

w32-no-usb-subranges is a variable defined in w32-win.el.gz.

Value

((2048 . 2303) (6320 . 6399) (6688 . 6911) (7104 . 7167) (7296 . 7423)
 (12256 . 12271) (42192 . 42239) (42656 . 42751) (43056 . 43071)
 (43232 . 43263) (43360 . 43519) (43616 . 44031) (55216 . 55295)
 (66048 . 66175) (66272 . 66303) (66384 . 66431) (66528 . 66559)
 (66736 . 67583) (67648 . 67839) (67904 . 68095) (68192 . 73727)
 (74880 . 118783) (119376 . 119551) (119680 . 119807)
 (120832 . 126975) (127136 . 131071) (173792 . 194559)
 (195104 . 917503) (917632 . 917759) (918000 . 1044479))

Documentation

List of Unicode subranges whose support cannot be announced by a font.

The FONTSIGNATURE structure reported by MS-Windows for a font includes 123 Unicode Subset bits (USBs) to identify subranges of the Unicode codepoint space supported by the font. Since the number of bits is fixed, not every Unicode block can have a corresponding USB bit; fonts that support characters from blocks that have no USBs cannot communicate their support to Emacs, unless the font is opened and physically tested for glyphs for characters from these blocks.

Source Code

;; Defined in /usr/src/emacs/lisp/term/w32-win.el.gz
;; The value of the following variable was calculated using the table in
;; https://docs.microsoft.com/windows/desktop/Intl/unicode-subset-bitfields,
;; by looking for Unicode subranges for which no USB bits are defined.
(defconst w32-no-usb-subranges
  '((#x000800 . #x0008ff)
    (#x0018b0 . #x0018ff)
    (#x001a20 . #x001aff)
    (#x001bc0 . #x001bff)
    (#x001c80 . #x001cff)
    (#x002fe0 . #x002fef)
    (#x00a4d0 . #x00a4ff)
    (#x00a6a0 . #x00a6ff)
    (#x00a830 . #x00a83f)
    (#x00a8e0 . #x00a8ff)
    (#x00a960 . #x00a9ff)
    (#x00aa60 . #x00abff)
    (#x00d7b0 . #x00d7ff)
    (#x010200 . #x01027f)
    (#x0102e0 . #x0102ff)
    (#x010350 . #x01037f)
    (#x0103e0 . #x0103ff)
    (#x0104b0 . #x0107ff)
    (#x010840 . #x0108ff)
    (#x010940 . #x0109ff)
    (#x010a60 . #x011fff)
    (#x012480 . #x01cfff)
    (#x01d250 . #x01d2ff)
    (#x01d380 . #x01d3ff)
    (#x01d800 . #x01efff)
    (#x01f0a0 . #x01ffff)
    (#x02a6e0 . #x02f7ff)
    (#x02fa20 . #x0dffff)
    (#x0e0080 . #x0e00ff)
    (#x0e01f0 . #x0fefff))
  "List of Unicode subranges whose support cannot be announced by a font.
The FONTSIGNATURE structure reported by MS-Windows for a font
includes 123 Unicode Subset bits (USBs) to identify subranges of
the Unicode codepoint space supported by the font.  Since the
number of bits is fixed, not every Unicode block can have a
corresponding USB bit; fonts that support characters from blocks
that have no USBs cannot communicate their support to Emacs,
unless the font is opened and physically tested for glyphs for
characters from these blocks.")