![[Contents]](../images/toc_d.gif)
![[Index]](../images/index_d.gif)
![[Help]](../images/help_d.gif)
![[Retrace]](../images/retrace_d.gif)
![[Browse <]](../images/prev.gif)
![[Browse >]](../images/next.gif)
* A sparse (but complete) sample font.
*
* 1. Assemble this file (assumed to have been saved as "suits8.asm"). For
* example, if you have the CAPE 680x0 assembler, and you have assigned
* "include:" to the directory containing your include files, use:
* CAsm -a "suits8.asm" -o "suits8.o" -i "include:"
*
* Link "suits8.o". For example, if you have Lattice, use:
* BLink from "suits8.o" to "suits8"
*
* 2. Create the subdirectory "Fonts:suits". Copy the file "suits8"
* (created in step 1) to "Fonts:suits/8".
*
* 3. Create a font contents file for the font. You can do this by two
* methods:
*
* a. Run the program "System/FixFonts" which will create the file
* "Fonts:suits.font" automatically.
* b. Use the NewFontContents() call in the diskfont library to create a
* FontContentsHeader structure, which can be saved in the Fonts:
* directory as "suits.font". This is essentially what FixFonts does.
*
* The next word contains the font YSize; in this case, 0x0008.
*
* The next byte contains the font Flags, in this case 0x00.
*
* The last byte contains the font characteristics, in this case 0x60. This
* says it is a disk-based font (bit 1 set) and the font has been removed
* (bit 7 set), saying that the font is not currently resident.
*
* Summary of suits.font file:
*
* Name: fch_FileID fch_NumEntries fc_FileName fc_YSize fc_Flags fc_Style
* Size: word word MAXFONTPATH bytes word byte byte
* Hex: 0f00 0001 73756974732F3800 0008 00 60
* ASCII: s u i t s / 8 \0
*
* The correct length of a font file may be calculated with this formula:
* length = ((number of font contents entries) * (MAXFONTPATH+4)) + 4. In
* this case (one entry), this becomes (MAXFONTPATH + 8) or 264.
*
* To try out this example font, do the following. Use the Fonts
* Preferences editor or a program that allows the user to select fonts.
* Choose the "suits" font in size 8. This example font defines ASCII
* characters 'a' 'b' 'c' and 'd' only. All other characters map to a
* rectangle, meaning "character unknown".
INCLUDE "exec/types.i"
INCLUDE "exec/nodes.i"
INCLUDE "libraries/diskfont.i"
MOVEQ #-1,D0 ; Provide an easy exit in case this file is
RTS ; "Run" instead of merely loaded.
DC.L 0 ; ln_Succ * These five entries comprise a Node
DC.L 0 ; ln_Pred * structure, used by the system to link
DC.B NT_FONT ; ln_Type * disk fonts into a list. See the
DC.B 0 ; ln_Pri * definition of the "DiskFontHeader"
DC.L fontName ; ln_Name * structure in the "libraries/diskfont.i"
* includefile for more information.
DC.W DFH_ID ; FileID
DC.W 1 ; Revision
DC.L 0 ; Segment
* The next MAXFONTNAME bytes are a placeholder. The name of the font
* contents file (e.g. "suits.font") will be copied here after this font
* descriptor is LoadSeg-ed into memory. The Name field could have been
* left blank, but inserting the font name and size (or style) allows one to
* tell something about the font by using "Type OPT H" on the file.
fontName:
DC.B "suits8" ; Name
* If your assembler needs an absolute value in place of the "length"
* variable, simply count the number of characters in Name and use that.
length EQU *-fontName ; Assembler calculates Name's length.
DCB.B MAXFONTNAME-length,0 ; Padding of null characters.
font:
DC.L 0 ; ln_Succ * The rest of the information is a
DC.L 0 ; ln_Pred * TextFont structure. See the
DC.B NT_FONT ; ln_Type * "graphics/text.i" include file for
DC.B 0 ; ln_Pri * more information.
DC.L fontName ; ln_Name
DC.L 0 ; mn_ReplyPort
DC.W 0 ; (Reserved for 1.4 system use.)
DC.W 8 ; tf_YSize
DC.B 0 ; tf_Style
DC.B FPF_DESIGNED!FPF_PROPORTIONAL!FPF_DISKFONT ; tf_Flags
DC.W 14 ; tf_XSize
DC.W 6 ; tf_Baseline <----* tf_Baseline must be no greater
DC.W 1 ; tf_BoldSmear * than tf_YSize-1, otherwise
DC.W 0 ; tf_Accessors * algorithmically-generated styles
DC.B 97 ; tf_LoChar * (italic in particular) can
DC.B 100 ; tf_HiChar * corrupt system memory.
DC.L fontData ; tf_CharData
DC.W 8 ; tf_Modulo <- * add this to the data pointer to go
; * from one row of a character to the
* next row of it.
DC.L fontLoc ; tf_CharLoc <------* bit position in the font data
DC.L fontSpace ; tf_CharSpace * at which the character begins.
DC.L fontKern ; tf_CharKern
* The four characters of this font define the four playing-card suit
* symbols. The heart, club, diamond, and spade map to the lower-case ASCII
* characters 'a', 'b', 'c', and 'd' respectively The fifth entry in the
* table is the character to be output when there is no entry defined in the
* character set for the requested ASCII value. Font data is bit-packed
* edge to edge to save space.
fontData: ; 97 (a) 98 (b) 99 (c) 100 (d) 255
DC.W $071C0,$08040,$070FF,$0F000 ; < X X X X >
DC.W $0FBE3,$0E0E0,$0F8C0,$03000 ; .@@@...@@@. .....@..... ...@... ....@@@.... @@@@@@@@@@@@
DC.W $07FCF,$0F9F3,$026C0,$03000 ; @@@@@.@@@@@ ...@@@@@... ..@@@.. ...@@@@@... @@........@@
DC.W $03F9F,$0FFFF,$0FFC0,$03000 ; .@@@@@@@@@. .@@@@@@@@@. .@@@@@. .@@..@..@@. @@........@@
DC.W $01F0E,$0B9F3,$026C0,$03000 ; ..@@@@@@@.. @@@@@@@@@@@ @@@@@@@ @@@@@@@@@@@ @@........@@
DC.W $00E00,$080E0,$020C0,$03000 ; ...@@@@@... .@@@.@.@@@. .@@@@@. .@@..@..@@. @@........@@
DC.W $00403,$0E040,$0F8FF,$0F000 ; ....@@@.... .....@..... ..@@@.. .....@..... @@........@@
DC.W $00000,$00000,$00000,$00000 ; .....@..... ...@@@@@... ...@... ...@@@@@... @@@@@@@@@@@@
DC.W $00000,$00000,$00000,$00000 ; ........... ........... ....... ........... ............
fontLoc: ; The fontLoc information is used to "unpack" the
DC.L $00000000B ; fontData. Each pair of words specifies how the
DC.L $0000B000B ; characters are bit-packed. For example, the first
DC.L $000160007 ; character starts at bit position 0x0000, and is
DC.L $0001D000B ; 0x000B (11) bits wide. The second character starts
DC.L $00028000C ; at bit position 0x000B and is 0x000B bits wide, and
; so on. This tellsthe font handler how to unpack
; the bits from the array.
fontSpace: ; fontSpace array: Use a space this wide
DC.W 000012,000012 ; to contain this character when it is
DC.W 000008,000012,000013 ; printed. For reverse-path fonts these
; values would be small or negative.
fontKern: ; fontKern array: Place a space this wide
DC.W 000001,000001 ; after the corresponding character to
DC.W 000001,000001,000001 ; separate it from the following character.
; For reverse-path fonts these values would
; be large negative numbers, approximately
; the width of the characters.
fontEnd:
END
[Back to Amiga Developer Docs]