.\"     $NetBSD: wsfont.9,v 1.18 2012/01/13 23:09:51 wiz Exp $
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.\" by Gregory McGarry.
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.Dd January 13, 2012
.Dt WSFONT 9
.Os
.Sh NAME
.Nm wsfont ,
.Nm wsfont_init ,
.Nm wsfont_matches ,
.Nm wsfont_find ,
.Nm wsfont_add ,
.Nm wsfont_remove ,
.Nm wsfont_enum ,
.Nm wsfont_lock ,
.Nm wsfont_unlock ,
.Nm wsfont_map_unichar
.Nd wscons font support
.Sh SYNOPSIS
.In dev/wscons/wsconsio.h
.In dev/wsfont/wsfont.h
.Ft void
.Fn wsfont_init "void"
.Ft int
.Fn wsfont_matches "struct wsdisplay_font *font" "const char *name" \
"int width" "int height" "int stride" "int flags"
.Ft int
.Fn wsfont_find "const char *name" "int width" "int height" "int stride" \
"int bitorder" "int byteorder" "int flags"
.Ft int
.Fn wsfont_add "struct wsdisplay_font *font" "int copy"
.Ft int
.Fn wsfont_remove "int cookie"
.Ft void
.Fn wsfont_enum "void (*callback)(const char *, int, int, int)"
.Ft int
.Fn wsfont_lock "int cookie" "struct wsdisplay_font **ptr"
.Ft int
.Fn wsfont_unlock "int cookie"
.Ft int
.Fn wsfont_map_unichar "struct wsdisplay_font *font" "int c"
.Sh DESCRIPTION
The
.Nm
module is a component of the
.Xr wscons 9
framework to provide access to display fonts.
Fonts may be loaded dynamically into the kernel or included statically
in the kernel at compile time.
Display drivers which emulate a glass-tty console on a bit-mapped
display can add, remove and find fonts for use by device-dependent
blitter operations.
.Pp
The primary data type for manipulating fonts is the
.Em wsdisplay_font
structure in
.Pa dev/wscons/wsconsio.h :
.Bd -literal
struct wsdisplay_font {
	const char *name;	/* font name */
	int firstchar;
	int numchars;		/* size of font table */
	int encoding;		/* font encoding */
	u_int fontwidth;	/* character width */
	u_int fontheight;	/* character height */
	u_int stride;
	int bitorder;
	int byteorder;
	void *data;		/* pointer to font table */
};
.Ed
.Pp
The maximum font table size is
.Em WSDISPLAY_MAXFONTSZ .
.Pp
The
.Nm
framework supports fonts with the following encodings:
.Bl -tag -width compact
.It Dv WSDISPLAY_FONTENC_ISO
ISO-encoded fonts.
.It Dv WSDISPLAY_FONTENC_IBM
IBM-encoded fonts commonly available for IBM CGA, EGA and VGA display
adapters.
.It Dv WSDISPLAY_FONTENC_PCVT
PCVT-encoding fonts distributed as part of the old PCVT terminal
emulation driver.
.It Dv WSDISPLAY_FONTENC_ISO7
ISO-encoded Greek fonts.
.It Dv WSDISPLAY_FONTENC_ISO2
ISO-encoded East European fonts.
.El
.Sh FUNCTIONS
.Bl -tag -width compact
.It Fn wsfont_init "void"
Initialise the font list with the built-in fonts.
.It Fn wsfont_matches "font" "name" "width" "height" "stride"
Matches the font
.Fa font
with the specifications
.Fa name ,
.Fa width ,
.Fa height ,
.Fa stride
and
.Fa flags .
Return zero if not matched and non-zero if matched.
The
.Fa flags
parameter has the same meaning as in
.Fn wsfont_find .
.It Fn wsfont_find "name" "width" "height" "stride" "bitorder" "byteorder" "flags"
Find the font called
.Fa name
from the fonts loaded into the kernel.
The font aspect is specified by
.Fa width ,
.Fa height ,
and
.Fa stride .
If
.Fn wsfont_find
is called with any of the parameters as 0, it indicates that we don't
care about that aspect of the font.
If the font is found, a (nonnegative-valued) cookie is returned which
can be used with the other functions.
.Pp
The
.Fa bitorder
and
.Fa byteorder
arguments are the bit order and byte order required.
Valid values are:
.Bl -tag -width compact
.It Dv WSDISPLAY_FONTORDER_KNOWN
The font is in known ordered format and doesn't need converting.
.It Dv WSDISPLAY_FONTORDER_L2R
The font is ordered left to right.
.It Dv WSDISPLAY_FONTORDER_R2L
The font is ordered right to left.
.El
.Pp
The
.Fa flags
parameter determines what type of font can be returned.
Any combination of the following values is allowed:
.Bl -tag -width compact
.It Dv WSFONT_FIND_BITMAP
To search bitmap fonts,
.It Dv WSFONT_FIND_ALPHA
to search anti-aliased fonts.
.El
When more flexibility is required,
.Fn wsfont_enum
should be used.
.It Fn wsfont_add "font" "copy"
Add a font
.Fa font
to the font list.
If the
.Fa copy
argument is non-zero, then the font is physically copied, otherwise a
reference to the original font is made.
.It Fn wsfont_remove "cookie"
Remove the font specified by
.Fa cookie
from the font list.
The value of cookie was returned by
.Fn wsfont_add .
.It Fn wsfont_enum "callback"
Enumerate the list of fonts.
For each font in the font list, the
.Fa callback
function argument is called with the arguments specifying the font
name, width, height and stride.
.It Fn wsfont_lock "cookie" "ptr"
Lock access to the font specified by
.Fa cookie
so that it cannot be unloaded from the kernel while is being used.
If the bit or byte order of the font to be locked differs from what
has been requested with
.Fn wsfont_find
then the glyph data will be modified to match.
At this point it may be necessary for
.Fn wsfont_lock
to make a copy of the font data; this action is transparent to the caller.
A later call to
.Fn wsfont_unlock
will free resources used by temporary copies.
.Pp
The address of the wsdisplay_font pointer for the specified font is returned in
the
.Fa ptr
argument.
.Pp
.Fn wsfont_lock
returns zero on success, or an error code on failure.
.It Fn wsfont_unlock "cookie"
Unlock the font specified by
.Fa cookie .
Returns zero on success, or an error code on failure.
.It Fn wsfont_map_unichar "font" "c"
Remap the unicode character
.Fa c
to glyph for font
.Fa font .
Returns the glyph on success or \-1 on error.
.El
.Sh CODE REFERENCES
The wscons subsystem is implemented within the directory
.Pa sys/dev/wscons .
The wsfont subsystem itself is implemented within the file
.Pa sys/dev/wsfont/wsfont.c .
.Sh SEE ALSO
.Xr wsfont 4 ,
.Xr wsfontload 8 ,
.Xr autoconf 9 ,
.Xr driver 9 ,
.Xr intro 9 ,
.Xr wscons 9 ,
.Xr wsdisplay 9