+++ /dev/null
-==================================================================
-Notes regarding fonts, code pages, and East Asian character widths
-==================================================================
-
-
-Registry settings
-=================
-
- * There are console registry settings in `HKCU\Console`. That key has many
- default settings (e.g. the default font settings) and also per-app subkeys
- for app-specific overrides.
-
- * It is possible to override the code page with an app-specific setting.
-
- * There are registry settings in
- `HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console`. In particular,
- the `TrueTypeFont` subkey has a list of suitable font names associated with
- various CJK code pages, as well as default font names.
-
- * There are two values in `HKLM\SYSTEM\CurrentControlSet\Control\Nls\CodePage`
- that specify the current code pages -- `OEMCP` and `ACP`. Setting the
- system locale via the Control Panel's "Region" or "Language" dialogs seems
- to change these code page values.
-
-
-Console fonts
-=============
-
- * The `FontFamily` field of `CONSOLE_FONT_INFOEX` has two parts:
- - The high four bits can be exactly one of the `FF_xxxx` font families:
- FF_DONTCARE(0x00)
- FF_ROMAN(0x10)
- FF_SWISS(0x20)
- FF_MODERN(0x30)
- FF_SCRIPT(0x40)
- FF_DECORATIVE(0x50)
- - The low four bits are a bitmask:
- TMPF_FIXED_PITCH(1) -- actually means variable pitch
- TMPF_VECTOR(2)
- TMPF_TRUETYPE(4)
- TMPF_DEVICE(8)
-
- * Each console has its own independent console font table. The current font
- is identified with an index into this table. The size of the table is
- returned by the undocumented `GetNumberOfConsoleFonts` API. It is apparently
- possible to get the table size without this API, by instead calling
- `GetConsoleFontSize` on each nonnegative index starting with 0 until the API
- fails by returning (0, 0).
-
- * The font table grows dynamically. Each time the console is configured with
- a previously-unused (FaceName, Size) combination, two entries are added to
- the font table -- one with normal weight and one with bold weight. Fonts
- added this way are always TrueType fonts.
-
- * Initially, the font table appears to contain only raster fonts. For
- example, on an English Windows 8 installation, here is the initial font
- table:
- font 0: 4x6
- font 1: 6x8
- font 2: 8x8
- font 3: 16x8
- font 4: 5x12
- font 5: 7x12
- font 6: 8x12 -- the current font
- font 7: 16x12
- font 8: 12x16
- font 9: 10x18
- `GetNumberOfConsoleFonts` returns 10, and this table matches the raster font
- sizes according to the console properties dialog.
-
- * With a Japanese or Chinese locale, the initial font table appears to contain
- the sizes applicable to both the East Asian raster font, as well as the
- sizes for the CP437/CP1252 raster font.
-
- * The index passed to `SetCurrentConsoleFontEx` apparently has no effect.
- The undocumented `SetConsoleFont` API, however, accepts *only* a font index,
- and on Windows 8 English, it switches between all 10 fonts, even font index
- #0.
-
- * If the index passed to `SetConsoleFont` identifies a Raster Font
- incompatible with the current code page, then another Raster Font is
- activated.
-
- * Passing "Terminal" to `SetCurrentConsoleFontEx` seems to have no effect.
- Perhaps relatedly, `SetCurrentConsoleFontEx` does not fail if it is given a
- bogus `FaceName`. Some font is still chosen and activated. Passing a face
- name and height seems to work reliably, modulo the CP936 issue described
- below.
-
-
-Console fonts and code pages
-============================
-
- * On an English Windows installation, the default code page is 437, and it
- cannot be set to 932 (Shift-JIS). (The API call fails.) Changing the
- system locale to "Japanese (Japan)" using the Region/Language dialog
- changes the default CP to 932 and permits changing the console CP between
- 437 and 932.
-
- * A console has both an input code page and an output code page
- (`{Get,Set}ConsoleCP` and `{Get,Set}ConsoleOutputCP`). I'm not going to
- distinguish between the two for this document; presumably only the output
- CP matters. The code page can change while the console is open, e.g.
- by running `mode con: cp select={932,437,1252}` or by calling
- `SetConsoleOutputCP`.
-
- * The current code page restricts which TrueType fonts and which Raster Font
- sizes are available in the console properties dialog. This can change
- while the console is open.
-
- * Changing the code page almost(?) always changes the current console font.
- So far, I don't know how the new font is chosen.
-
- * With a CP of 932, the only TrueType font available in the console properties
- dialog is "MS Gothic", displayed as "ＭＳ ゴシック". It is still possible to
- use the English-default TrueType console fonts, Lucida Console and Consolas,
- via `SetCurrentConsoleFontEx`.
-
- * When using a Raster Font and CP437 or CP1252, writing a UTF-16 codepoint not
- representable in the code page instead writes a question mark ('?') to the
- console. This conversion does not apply with a TrueType font, nor with the
- Raster Font for CP932 or CP936.
-
-
-ReadConsoleOutput and double-width characters
-==============================================
-
- * With a Raster Font active, when `ReadConsoleOutputW` reads two cells of a
- double-width character, it fills only a single `CHAR_INFO` structure. The
- unused trailing `CHAR_INFO` structures are zero-filled. With a TrueType
- font active, `ReadConsoleOutputW` instead fills two `CHAR_INFO` structures,
- the first marked with `COMMON_LVB_LEADING_BYTE` and the second marked with
- `COMMON_LVB_TRAILING_BYTE`. The flag is a misnomer--there aren't two
- *bytes*, but two cells, and they have equal `CHAR_INFO.Char.UnicodeChar`
- values.
-
- * `ReadConsoleOutputA`, on the other hand, reads two `CHAR_INFO` cells, and
- if the UTF-16 value can be represented as two bytes in the ANSI/OEM CP, then
- the two bytes are placed in the two `CHAR_INFO.Char.AsciiChar` values, and
- the `COMMON_LVB_{LEADING,TRAILING}_BYTE` values are also used. If the
- codepoint isn't representable, I don't remember what happens -- I think the
- `AsciiChar` values take on an invalid marker.
-
- * Reading only one cell of a double-width character reads a space (U+0020)
- instead. Raster-vs-TrueType and wide-vs-ANSI do not matter.
- - XXX: what about attributes? Can a double-width character have mismatched
- color attributes?
- - XXX: what happens when writing to just one cell of a double-width
- character?
-
-
-Default Windows fonts for East Asian languages
-==============================================
-CP932 / Japanese: "ＭＳ ゴシック" (MS Gothic)
-CP936 / Chinese Simplified: "新宋体" (SimSun)
-
-
-Unreliable character width (half-width vs full-width)
-=====================================================
-
-The half-width vs full-width status of a codepoint depends on at least these variables:
- * OS version (Win10 legacy and new modes are different versions)
- * system locale (English vs Japanese vs Chinese Simplified vs Chinese Traditional, etc)
- * code page (437 vs 932 vs 936, etc)
- * raster vs TrueType (Terminal vs MS Gothic vs SimSun, etc)
- * font size
- * rendered-vs-model (rendered width can be larger or smaller than model width)
-
-Example 1: U+2014 (EM DASH): East_Asian_Width: Ambiguous
---------------------------------------------------------
- rendered modeled
-CP932: Win7/8 Raster Fonts half half
-CP932: Win7/8 Gothic 14/15px half full
-CP932: Win7/8 Consolas 14/15px half full
-CP932: Win7/8 Lucida Console 14px half full
-CP932: Win7/8 Lucida Console 15px half half
-CP932: Win10New Raster Fonts half half
-CP932: Win10New Gothic 14/15px half half
-CP932: Win10New Consolas 14/15px half half
-CP932: Win10New Lucida Console 14/15px half half
-
-CP936: Win7/8 Raster Fonts full full
-CP936: Win7/8 SimSun 14px full full
-CP936: Win7/8 SimSun 15px full half
-CP936: Win7/8 Consolas 14/15px half full
-CP936: Win10New Raster Fonts full full
-CP936: Win10New SimSum 14/15px full full
-CP936: Win10New Consolas 14/15px half half
-
-Example 2: U+3044 (HIRAGANA LETTER I): East_Asian_Width: Wide
--------------------------------------------------------------
- rendered modeled
-CP932: Win7/8/10N Raster Fonts full full
-CP932: Win7/8/10N Gothic 14/15px full full
-CP932: Win7/8/10N Consolas 14/15px half(*2) full
-CP932: Win7/8/10N Lucida Console 14/15px half(*3) full
-
-CP936: Win7/8/10N Raster Fonts full full
-CP936: Win7/8/10N SimSun 14/15px full full
-CP936: Win7/8/10N Consolas 14/15px full full
-
-Example 3: U+30FC (KATAKANA-HIRAGANA PROLONGED SOUND MARK): East_Asian_Width: Wide
-----------------------------------------------------------------------------------
- rendered modeled
-CP932: Win7 Raster Fonts full full
-CP932: Win7 Gothic 14/15px full full
-CP932: Win7 Consolas 14/15px half(*2) full
-CP932: Win7 Lucida Console 14px half(*3) full
-CP932: Win7 Lucida Console 15px half(*3) half
-CP932: Win8 Raster Fonts full full
-CP932: Win8 Gothic 14px full half
-CP932: Win8 Gothic 15px full full
-CP932: Win8 Consolas 14/15px half(*2) full
-CP932: Win8 Lucida Console 14px half(*3) full
-CP932: Win8 Lucida Console 15px half(*3) half
-CP932: Win10New Raster Fonts full full
-CP932: Win10New Gothic 14/15px full full
-CP932: Win10New Consolas 14/15px half(*2) half
-CP932: Win10New Lucida Console 14/15px half(*2) half
-
-CP936: Win7/8 Raster Fonts full full
-CP936: Win7/8 SimSun 14px full full
-CP936: Win7/8 SimSun 15px full half
-CP936: Win7/8 Consolas 14px full full
-CP936: Win7/8 Consolas 15px full half
-CP936: Win10New Raster Fonts full full
-CP936: Win10New SimSum 14/15px full full
-CP936: Win10New Consolas 14/15px full full
-
-Example 4: U+4000 (CJK UNIFIED IDEOGRAPH-4000): East_Asian_Width: Wide
-----------------------------------------------------------------------
- rendered modeled
-CP932: Win7 Raster Fonts half(*1) half
-CP932: Win7 Gothic 14/15px full full
-CP932: Win7 Consolas 14/15px half(*2) full
-CP932: Win7 Lucida Console 14px half(*3) full
-CP932: Win7 Lucida Console 15px half(*3) half
-CP932: Win8 Raster Fonts half(*1) half
-CP932: Win8 Gothic 14px full half
-CP932: Win8 Gothic 15px full full
-CP932: Win8 Consolas 14/15px half(*2) full
-CP932: Win8 Lucida Console 14px half(*3) full
-CP932: Win8 Lucida Console 15px half(*3) half
-CP932: Win10New Raster Fonts half(*1) half
-CP932: Win10New Gothic 14/15px full full
-CP932: Win10New Consolas 14/15px half(*2) half
-CP932: Win10New Lucida Console 14/15px half(*2) half
-
-CP936: Win7/8 Raster Fonts full full
-CP936: Win7/8 SimSun 14px full full
-CP936: Win7/8 SimSun 15px full half
-CP936: Win7/8 Consolas 14px full full
-CP936: Win7/8 Consolas 15px full half
-CP936: Win10New Raster Fonts full full
-CP936: Win10New SimSum 14/15px full full
-CP936: Win10New Consolas 14/15px full full
-
-(*1) Rendered as a half-width filled white box
-(*2) Rendered as a half-width box with a question mark inside
-(*3) Rendered as a half-width empty box
-(!!) One of the only places in Win10New where rendered and modeled width disagree
-
-
-Windows quirk: unreliable font heights with CP936 / Chinese Simplified
-======================================================================
-
-When I set the font to 新宋体 17px, using either the properties dialog or
-`SetCurrentConsoleFontEx`, the height reported by `GetCurrentConsoleFontEx` is
-not 17, but is instead 19. The same problem does not affect Raster Fonts,
-nor have I seen the problem in the English or Japanese locales. I observed
-this with Windows 7 and Windows 10 new mode.
-
-If I set the font using the facename, width, *and* height, then the
-`SetCurrentConsoleFontEx` and `GetCurrentConsoleFontEx` values agree. If I
-set the font using *only* the facename and height, then the two values
-disagree.
-
-
-Windows bug: GetCurrentConsoleFontEx is initially invalid
-=========================================================
-
- - Assume there is no configured console font name in the registry. In this
- case, the console defaults to a raster font.
- - Open a new console and call the `GetCurrentConsoleFontEx` API.
- - The `FaceName` field of the returned `CONSOLE_FONT_INFOEX` data
- structure is incorrect. On Windows 7, 8, and 10, I observed that the
- field was blank. On Windows 8, occasionally, it instead contained:
- U+AE72 U+75BE U+0001
- The other fields of the structure all appeared correct:
- nFont=6 dwFontSize=(8,12) FontFamily=0x30 FontWeight=400
- - The `FaceName` field becomes initialized easily:
- - Open the console properties dialog and click OK. (Cancel is not
- sufficient.)
- - Call the undocumented `SetConsoleFont` with the current font table
- index, which is 6 in the example above.
- - It seems that the console uncritically accepts whatever string is
- stored in the registry, including a blank string, and passes it on the
- the `GetCurrentConsoleFontEx` caller. It is possible to get the console
- to *write* a blank setting into the registry -- simply open the console
- (default or app-specific) properties and click OK.
projects / VSoRC / .git / blobdiff