CreateFont
The CreateFont
function creates a logical font that has specific characteristics. The logical
font can subsequently be selected as the font for any device.
HFONT CreateFont(
int nHeight, |
// logical height
of font |
int nWidth, |
// logical average
character width |
int nEscapement, |
// angle of
escapement |
int nOrientation, |
// base-line
orientation angle |
int fnWeight, |
// font weight |
DWORD fdwItalic, |
// italic attribute
flag |
DWORD fdwUnderline, |
// underline
attribute flag |
DWORD fdwStrikeOut, |
// strikeout
attribute flag |
DWORD fdwCharSet, |
// character set
identifier |
DWORD fdwOutputPrecision, |
// output precision
|
DWORD fdwClipPrecision, |
// clipping
precision |
DWORD fdwQuality, |
// output quality |
DWORD fdwPitchAndFamily, |
// pitch and family
|
LPCTSTR lpszFace |
// pointer to
typeface name string |
); |
|
Parameters
nHeight
Specifies the
height, in logical units, of the font s character cell or character. The
character height value (also known as the em height) is the character cell
height value minus the internal-leading value. The font mapper interprets the
value specified in nHeight in the following manner:
Value |
Meaning |
> 0 |
The font
mapper transforms this value into device units and matches it against the
cell height of the available fonts. |
0 |
The font
mapper uses a default height value when it searches for a match. |
< 0 |
The font
mapper transforms this value into device units and matches its absolute value
against the character height of the available fonts. |
For all
height comparisons, the font mapper looks for the largest font that does not
exceed the requested size.
This mapping occurs when the font is used for the first time.
For the MM_TEXT mapping mode, you can use the following formula to
specify a height for a font with a specified point size:
nHeight = -MulDiv(PointSize, GetDeviceCaps(hDC,
LOGPIXELSY), 72);
nWidth
Specifies the
average width, in logical units, of characters in the requested font. If this
value is zero, the font mapper chooses a closest match value. The closest
match value is determined by comparing the absolute values of the difference
between the current device s aspect ratio and the digitized aspect ratio of
available fonts.
nEscapement
Specifies the
angle, in tenths of degrees, between the escapement vector and the x-axis of
the device. The escapement vector is parallel to the base line of a row of
text.
Windows
NT:
When the
graphics mode is set to GM_ADVANCED, you can specify the escapement angle of
the string independently of the orientation angle of the string s characters.
When the
graphics mode is set to GM_COMPATIBLE, nEscapement specifies both the
escapement and orientation. You should set nEscapement and nOrientation
to the same value.
Windows
95:
The nEscapement
parameter specifies both the escapement and orientation. You should set nEscapement
and nOrientation to the same value.
nOrientation
Specifies the
angle, in tenths of degrees, between each character s base line and the x-axis
of the device.
fnWeight
Specifies the
weight of the font in the range 0 through 1000. For example, 400 is normal and
700 is bold. If this value is zero, a default weight is used.
The following values are defined for convenience:
Value |
Weight |
FW_DONTCARE |
0 |
FW_THIN |
100 |
FW_EXTRALIGHT |
200 |
FW_ULTRALIGHT |
200 |
FW_LIGHT |
300 |
FW_NORMAL |
400 |
FW_REGULAR |
400 |
FW_MEDIUM |
500 |
FW_SEMIBOLD |
600 |
FW_DEMIBOLD |
600 |
FW_BOLD |
700 |
FW_EXTRABOLD |
800 |
FW_ULTRABOLD |
800 |
FW_HEAVY |
900 |
FW_BLACK |
900 |
fdwItalic
Specifies an
italic font if set to TRUE.
fdwUnderline
Specifies an
underlined font if set to TRUE.
fdwStrikeOut
Specifies a
strikeout font if set to TRUE.
fdwCharSet
Specifies the
character set. The following values are predefined:
ANSI_CHARSET
DEFAULT_CHARSET
SYMBOL_CHARSET
SHIFTJIS_CHARSET
GB2312_CHARSET
HANGEUL_CHARSET
CHINESEBIG5_CHARSET
OEM_CHARSET
Windows
95 only:
JOHAB_CHARSET
HEBREW_CHARSET
ARABIC_CHARSET
GREEK_CHARSET
TURKISH_CHARSET
THAI_CHARSET
EASTEUROPE_CHARSET
RUSSIAN_CHARSET
MAC_CHARSET
BALTIC_CHARSET
The OEM_CHARSET value specifies a character set that is
operating-system dependent.
You can use the DEFAULT_CHARSET value to allow the name and size of a
font to fully describe the logical font. If the specified font name does not
exist, a font from any character set can be substituted for the specified font,
so you should use DEFAULT_CHARSET sparingly to avoid unexpected results.
Fonts with other character sets may exist in the operating system. If an
application uses a font with an unknown character set, it should not attempt to
translate or interpret strings that are rendered with that font.
This parameter is important in the font mapping process. To ensure
consistent results, specify a specific character set. If you specify a typeface
name in the lpszFace parameter, make sure that the fdwCharSet
value matches the character set of the typeface specified in lpszFace.
fdwOutputPrecision
Specifies the
output precision. The output precision defines how closely the output must
match the requested font s height, width, character orientation, escapement,
pitch, and font type. It can be one of the following values:
Value |
Meaning |
OUT_CHARACTER_PRECIS |
Not used. |
OUT_DEFAULT_PRECIS |
Specifies
the default font mapper behavior. |
OUT_DEVICE_PRECIS |
Instructs
the font mapper to choose a Device font when the system contains multiple
fonts with the same name. |
OUT_OUTLINE_PRECIS |
Windows
NT: This value instructs the font
mapper to choose from TrueType and other outline-based fonts. Windows
95: This value is not used. |
OUT_RASTER_PRECIS |
Instructs
the font mapper to choose a raster font when the system contains multiple
fonts with the same name. |
OUT_STRING_PRECIS |
This value
is not used by the font mapper, but it is returned when raster fonts are
enumerated. |
OUT_STROKE_PRECIS |
Windows
NT: This value is not used by the
font mapper, but it is returned when TrueType, other outline-based fonts, and
vector fonts are enumerated. Windows
95: This value is used to map
vector fonts, and is returned when TrueType or vector fonts are enumerated. |
OUT_TT_ONLY_PRECIS |
Instructs
the font mapper to choose from only TrueType fonts. If there are no TrueType
fonts installed in the system, the font mapper returns to default behavior. |
OUT_TT_PRECIS |
Instructs
the font mapper to choose a TrueType font when the system contains multiple
fonts with the same name. |
Applications
can use the OUT_DEVICE_PRECIS, OUT_RASTER_PRECIS, and OUT_TT_PRECIS values to
control how the font mapper chooses a font when the operating system contains
more than one font with a specified name. For example, if an operating system
contains a font named Symbol in raster and TrueType form, specifying
OUT_TT_PRECIS forces the font mapper to choose the TrueType version. Specifying
OUT_TT_ONLY_PRECIS forces the font mapper to choose a TrueType font, even if it
must substitute a TrueType font of another name.
fdwClipPrecision
Specifies the
clipping precision. The clipping precision defines how to clip characters that
are partially outside the clipping region. It can be one or more of the
following values:
Value |
Meaning |
CLIP_DEFAULT_PRECIS |
Specifies
default clipping behavior. |
CLIP_CHARACTER_PRECIS |
Not used. |
CLIP_STROKE_PRECIS |
Not used by
the font mapper, but is returned when raster, vector, or TrueType fonts are
enumerated. Windows
NT: For compatibility, this value
is always returned when enumerating fonts. |
CLIP_MASK |
Not used. |
CLIP_EMBEDDED |
You must
specify this flag to use an embedded read-only font. |
CLIP_LH_ANGLES |
When this
value is used, the rotation for all fonts depends on whether the orientation
of the coordinate system is left-handed or right-handed. If not
used, device fonts always rotate counterclockwise, but the rotation of other
fonts is dependent on the orientation of the coordinate system. For more
information about the orientation of coordinate systems, see the description of
the nOrientation parameter |
CLIP_TT_ALWAYS |
Not used. |
fdwQuality
Specifies the
output quality. The output quality defines how carefully GDI must attempt to
match the logical-font attributes to those of an actual physical font. It can
be one of the following values:
Value |
Meaning |
DEFAULT_QUALITY |
Appearance
of the font does not matter. |
DRAFT_QUALITY |
Appearance
of the font is less important than when the PROOF_QUALITY value is used. For
GDI raster fonts, scaling is enabled, which means that more font sizes are
available, but the quality may be lower. Bold, italic, underline, and
strikeout fonts are synthesized if necessary. |
PROOF_QUALITY |
Character
quality of the font is more important than exact matching of the logical-font
attributes. For GDI raster fonts, scaling is disabled and the font closest in
size is chosen. Although the chosen font size may not be mapped exactly when
PROOF_QUALITY is used, the quality of the font is high and there is no
distortion of appearance. Bold, italic, underline, and strikeout fonts are
synthesized if necessary. |
fdwPitchAndFamily
Specifies the
pitch and family of the font. The two low-order bits specify the pitch of the
font and can be one of the following values:
DEFAULT_PITCH
FIXED_PITCH
VARIABLE_PITCH
The four high-order bits specify the font family and can be one of the
following values:
Value |
Description |
FF_DECORATIVE |
Novelty
fonts. Old English is an example. |
FF_DONTCARE |
Don t care
or don t know. |
FF_MODERN |
Fonts with
constant stroke width, with or without serifs. Pica, Elite, and Courier New are examples. |
FF_ROMAN |
Fonts with
variable stroke width and with serifs. MS Serif is an example. |
FF_SCRIPT |
Fonts
designed to look like handwriting. Script and Cursive are examples. |
FF_SWISS |
Fonts with
variable stroke width and without serifs. MS Sans Serif is an example. |
An application can specify a value for the fdwPitchAndFamily
parameter by using the Boolean OR operator to join a pitch constant with a
family constant.
Font families describe the look of a font in a general way. They are
intended for specifying fonts when the exact typeface requested is not
available.
lpszFace
Points to a
null-terminated string that specifies the typeface name of the font. The length
of this string must not exceed 32 characters, including the null terminator.
The EnumFontFamilies
If lpszFace is NULL or points to an empty string, GDI uses the
first font that matches the other specified attributes.
Return Values
If the
function succeeds, the return value is a handle to a logical font.
If the
function fails, the return value is NULL. To get extended error information,
call GetLastError
Remarks
When you no
longer need the font, call the DeleteObject function to delete it.
To help
protect the copyrights of vendors who provide fonts for Windows operating
systems, applications should always report the exact name of a selected font.
Because available fonts can vary from system to system, do not assume that the
selected font is always the same as the requested font. For example, if you
request a font named Palatino, but no such font is available on the system,
the font mapper will substitute a font that has similar attributes but a
different name. Always report the name of the selected font to the user.
See Also