.\"	$OpenBSD: wsfont_init.9,v 1.2 2019/05/10 17:24:53 schwarze Exp $
.\"     $NetBSD: wsfont.9,v 1.18 2012/01/13 23:09:51 wiz Exp $
.\"
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.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Gregory McGarry.
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.Dd $Mdocdate: May 10 2019 $
.Dt WSFONT_INIT 9
.Os
.Sh NAME
.Nm wsfont_init ,
.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_find "const char *name" "int width" "int height" "int stride"
.Ft int
.Fn wsfont_add "struct wsdisplay_font *font" "int copy"
.Ft int
.Fn wsfont_remove "int cookie"
.Ft void
.Fn wsfont_enum "int (*cb)(void *, struct wsdisplay_font *)" "void *cbarg"
.Ft int
.Fn wsfont_lock "int cookie" "struct wsdisplay_font **ptr" "int bitorder" \
"int byteorder"
.Ft int
.Fn wsfont_unlock "int cookie"
.Ft int
.Fn wsfont_map_unichar "struct wsdisplay_font *font" "int c"
.Sh DESCRIPTION
The wsfont module is a component of the wscons
.\" .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
.Vt wsdisplay_font
structure in
.In dev/wscons/wsconsio.h :
.Bd -literal
struct wsdisplay_font {
	char name[WSFONT_NAME_SIZE];	/* font name */
	int index;
	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 *cookie;
	void *data;			/* pointer to font table */
};
.Ed
.Pp
The maximum font table size is
.Dv WSDISPLAY_MAXFONTSZ .
.Pp
The wsfont 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.
.El
.Sh FUNCTIONS
.Bl -tag -width compact
.It Fn wsfont_init "void"
Initialise the font list with the built-in fonts.
.It Fn wsfont_find "name" "width" "height" "stride"
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
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" "cbarg"
Enumerate the list of fonts.
For each font in the font list, the
.Fa callback
function argument is called with the
.Fa cbarg
argument.
.It Fn wsfont_lock "cookie" "ptr" "bitorder" "byteorder"
Lock access to the font specified by
.Fa cookie
so that it cannot be unloaded from the kernel while it is being used.
If the bit or byte order of the font to be locked differs from what
has been requested via the
.Fa bitorder
and
.Fa byteorder
arguments, then the glyph data will be modified to match.
.Pp
The address of the
.Vt wsdisplay_font
pointer for the specified font is returned in
the
.Fa ptr
argument.
.Pp
.Fn wsfont_lock
returns lockcount on success, or an error code on failure.
.It Fn wsfont_unlock "cookie"
Unlock the font specified by
.Fa cookie .
Returns lockcount 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 wsfontload 8 ,
.Xr intro 9