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Diffstat (limited to 'static/v10/man9/font.9')
| -rw-r--r-- | static/v10/man9/font.9 | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/static/v10/man9/font.9 b/static/v10/man9/font.9 new file mode 100644 index 00000000..e8733eaa --- /dev/null +++ b/static/v10/man9/font.9 @@ -0,0 +1,110 @@ +.TH FONT 9.5 +.CT 2 comm_term +.SH NAME +font \- jerq font layouts +.SH SYNOPSIS +.B #include <jerq.h> +.br +.B #include <font.h> +.PP +.B typedef struct Fontchar Fontchar; +.br +.B typedef struct Font Font; +.PP +.B extern Font defont; +.SH DESCRIPTION +A +.I Font +is a character set, stored as a single +Bitmap +with the characters +placed side-by-side. +It is described by the following data structures. +.IP +.EX +.ta +.5i +\w'unsigned char bottom; 'u +typedef struct Fontchar { + short x; /* left edge of bits */ + unsigned char top; /* first non-zero scan-line */ + unsigned char bottom; /* last non-zero scan-line */ + char left; /* offset of baseline */ + unsigned char width; /* width of baseline */ +} Fontchar; +typedef struct Font { + short n; /* number of chars in font */ + char height; /* height of bitmap */ + char ascent; /* top of bitmap to baseline */ + long unused; + Bitmap *bits; /* where the characters are */ + Fontchar info[n+1]; /* n+1 character descriptors */ +} Font; +.EE +.PP +Characters in +.L bits +abut exactly, so the displayed width of the character +.I c +is +.BI Font.info[ c +1].x\ -\ Font.info[ c ].x . +The first +.L left +columns of pixels in a character overlap the previous character. +The upper left corner of the nonempty columns appears at +.RB ( x, 0) +in the bitmap. +.L Width +is the distance to move horizontally after drawing a character. +The font bitmap has a fixed +.LR height ; +parameters +.L top +and +.L bottom +may speed up the copying of a character. +.PP +Characters are positioned by their upper left corners. +.PP +Fonts are stored on disk in binary with byte +order that of the terminal. +First in the file is the Font structure +with +.B bits +elided. +The data for the bitmap follows. +The header for the bitmap must be inferred from +.B Font.height +and +.BR Font.info[Font.n].x . +.SH EXAMPLES +.EX +Fontchar *i = f->info + c; +bitblt(f->bits, Rect(i->x, i->top, (i+1)->x, i->bottom), + &display, Pt(p.x+i->left, p.y+i->top), fc); +p.x += i->width; +.EE +.ns +.IP +Copy character +.I c +from font +.I f +to point +.I p +with Code +.B F_XOR +or +.BR F_OR . +.PP +For Code +.LR F_STORE , +use +.LR "Rect(i->x, 0, (i+1)->x, f->height)" . +.SH SEE ALSO +.IR jf (9.1), +.IR string (9.3), +.IR getfont (9.1) +.SH BUGS +The +.L unused +field is used, by +.IR getfont (9.1). |