Belgian Amiga Club - ADF Collection/BS1 part 41.zip/BS1 part 41/ACU dox disk 6.adf/LionFonts

Text File | 1989-02-01 | 43KB | 680 lines

                         FontFacts: Secrets & Tips
                 (C) Copyright September 1987 by Lion Kuntz

                          Lion's Amiga Art Studio
                POB 42252, San Francisco, California, 94142
          [phone]  BBS,  [phone] Tech Support Phone




     Amiga fonts are the cornerstone of Desktop  Publishing, and the single
 most vital ingredient  in  Desktop  Video  presentations,  but  seem to be
 considered of little or no value by many.  Even programmers who set out to
 create the world's most impressive  page  make-up program seem not able to
 understand how to make using  fonts  in  their  program easy and painfree.
 Programmers  who  sell  their   product   as  being  useful  for  Business
 Presentations, Video Titles, and Flashy  Sexy Advertising designing forget
 to let the user have an easy way to load and use fonts.

     Why has there been so much mystery  surrounding  fonts, and why has it
 been the last feature of the Amiga to  have some standardized way of being
 accessed?

      I served in  the  graphic  arts  field  as  a  real  typographer, art
 director, and editor, for small local  magazines and newspapers, and I had
 to select typestyles, hire type shops,  and proofread copy before print. I
 would like to explain some of the differences between typography and Amiga
 Fonts, and the differences between various Amiga programs which use fonts.

      Everyone knows about Guttenberg, the  first  mass production printer,
 but how many people know that the whole alphabet had not been invented yet
 in Guttenberg's time? The letters  "J",  "U",  and "W" were spoken but not
 printed until several  more  centuries  later.  The  written language, and
 written communications,  have  continuously  evolved  for the past 100,000
 years, and the Amiga  is  a  continually  evolving  example  of the latest
 efforts to provide communications between persons.

      The Amiga screen  is  a  painting  using  electron  beams  guided  by
 electronics, constantly being  refreshed  or  changed 60 times per second.
 There are three electron  beams:  Red,  Green,  and  Blue, and they travel
 across the face of  the  screen  drawing  lines  of  dots of color glowing
 behind them as they go.  Because  of  this  it  is  possible to change the
 Typefaces and look of the printed  word  much faster than the eye can see.
 The Amiga has animated  fonts,  color-cycling  fonts,  multi-color  fonts,
 scrolling fonts, and more. The  user  only  sees  the dots of light on the
 screen and never knows about the  differences  used  by the programmers to
 produce those effects. It can be frustrating to find that fonts may not be
 compatible with some  programs,  or  the  printout  may  look considerably
 different than the screen image.

      First let me define "FONT". A "FONT" is a single instance of a set of
 characters in a single size, with one  single picture of each character in
 the set. A Font may have only one  character,  or it may have hundreds, or
 any number  in-between.  On  the  Amiga  computer  there  are  a number of
 different kinds of fonts. There are two  "ROM-fonts", Topaz 8 and Topaz 9.
 These are always available in memory for all programs to use, and are part
 of the KickStart operating system. A  second,  more common type of font is
 "DISK-font", and  is  software  modules  stored  on  disk, and loaded into
 programs on request.  A  sub-category  of  DISK-font  is COLOR-font, which
 shares all the qualities of  a  standard  DISK-font,  but adds information
 about additional colors  to  embellish  the  characters of the font. Other
 forms of font is the "STROKE-font"  and  the  "POLYGON-font", which differ
 from the above fonts in important ways.

      Most Amiga owners will be concerned with  using DISK-fonts. These are
 the ones you will be using in your Deluxe  Paint II, PageSetter, Publisher
 1000, City Desk, Shakespeare, Deluxe Print, Notepad, Deluxe Video, Images,
 Express Paint, E/FX, WordPerfect, Fast Fonts, TV*Text, SetFont, VisaWrite,
 ProWrite, Genlock Titler, and to some extent with CGI Pro Video, and Aegis
 VideoTitler. New programs  are  coming  out  weekly, so there are more and
 will be more programs to use DISK-fonts.

      DISK-fonts are sets of software data which come in three components.
      1) Each font has a home directory  where  there  is an important file
 called the "dot font"  file.  This  is  named  the  same  name as the font
 itself, and has a five character suffix: ".font".
      2) Each font has a subdirectory in the  home directory named the same
 as the font itself.
      3) Each individual font  has  a  datafile  which  is  inside the font
 directory which is inside the home directory.

      The dot-font file serves two important purposes: it is a pointer, and
 it is an index. As a pointer, the dot-font  file simply points to the font
 directory of the same name as its'  prefix.  As an index the dot-font file
 serves to keep an accurate list of what datafiles are actually in the font
 directory, and some attributes of the fonts found there.

      The Amiga Operating System  makes  some  assumptions  about important
 things at startup-time, when you put the WorkBench disk in the drive DF0:.

      Certain ASSIGNments are made at that  time,  being, SYS:, C:, S:, L:,
 LIBS:, DEVS:, and FONTS:.  Unless  you  change  these  the Amiga Operating
 System will default to  the  bootup-WorkBench  disk,  to a directory named
 fonts, as the home directory of your supply of fonts. If there is no FONTS
 directory on your WorkBench disk, it defaults to the ROM-fonts.

      You can change where the  system  searches  for  fonts  using the CLI
 command ASSIGN. Please consult a good AmigaDOS manual on the three ways to
 use the ASSIGN command. Inter/Active  Softworks  of San Francisco provides
 an icon to click to  enter  a  new  font  home  directory  path  from  the
 WorkBench screen,  and  this  FontAssign  program  is  provided with their
 Calligrapher and other  products.  The  FontAssign  program has generously
 been placed in the public domain by the publisher and may be found at your
 local users group library or favorite BBS.

      You may safely store other files in  the  fonts home directory, since
 the  operating  system  examines  each  file  for  the  ".font"  suffix to
 determine which are fonts and which are not.

      Programmers may employ a direct  method  of locating fonts, bypassing
 the operating system. The program may  be instructed to take a direct path
 to some specific location and load font  files with some specific names or
 extension suffix  on  the  filenames.  This  is  rare  now but was seen on
 program disks at the time of the Amiga release, and is still used for some
 games.

      Programmers may also decide to  use  some  or  all of the information
 contained in  the  dot-font  pointer/index  files.  This  is the cause for
 erratic operation between programs as to whether or not your fonts will be
 successfully loaded or not.

      An example of a common problem is  when  people find space cramped on
 their WorkBench disk they  may  delete  some  font datafiles of sizes they
 never use. They do not rebuild  the  dot-font  file,  and  the index still
 records the existence of  fonts  which  are  deleted.  In this case Deluxe
 Paint II will find the  remaining  fonts  and  provide a list of available
 sizes which actually do exist. This is because DPaint II ignores the index
 part of the dot-font file, but uses only  the pointer to find the existing
 sizes. Notepad and  Pagesetter,  on  the  other  hand,  examine  the index
 portion of the dot-font file, and  examine  the font directory to see that
 all fonts which are listed  actually  do  exist.  If Notepad or Pagesetter
 find that there is discrepancy  they  assume  that  something is seriously
 wrong with the dot-font  file  and  ignore  all  fonts  pointed to by that
 dot-font file. In other words, as far as these two programs are concerned,
 if you delete one size you might  as  well  delete  them all, because none
 will be used until you rebuild the dot-font file.

      Rebuilding  a  dot-font  file  is  easy  with  another  utility  from
 Inter/Active Softworks, called  FontFixer.  Again this is provided free on
 Calligrapher  disk,  and  other  products  from  the  publisher,   and has
 generously be placed in public domain.

      If your dot-font file is updated  correctly,  all  programs should be
 able to find and load  all  sizes  of  existing  fonts  in  the fonts home
 directory.

      If you are using a hard drive for storage of your fonts you will soon
 discover that your list of  sizes  grows  too  immense  to be displayed by
 pull-down menus. You should seriously consider waiting on buying a product
 which uses pull-down menus for font lists,  until the publisher releases a
 newer version which has  a  requestor  window  to  select fonts. DPaint II
 gives an unpleasant surprise if the list  grows too long: if the bottom of
 the pull-down menu touches the bottom of the screen your screen blanks. It
 appears that imminent GURU failure  is  due. This is harmless, but it does
 prevent you from using your fonts.

      Since there are now hundreds of fonts, completely filling many disks,
 being able to handle lots of fonts,  and  swap  between disks of fonts, is
 important to Amiga  owners.  Programmers  have  not addressed this problem
 adequately so far.

      There is a temporary solution  I  use,  but  it has a danger you must
 keep in mind. By using a  trick  on  the  Amiga  Operating  System you can
 relabel disks you use for FONTS collections to name "FONTS". The operating
 system gives a higher  priority  to  disks  than  to  directories. It also
 ASSIGNs disks  automatically  while  they  are  mounted,  so  a disk named
 "FONTS" becomes a disk named  "FONTS:".  (Note  the colon after the name.)
 Unless you relabel the  disk you  will  not be able to reASSIGN fonts. But
 as soon as the disk is inserted it  becomes  the  home directory for fonts
 while the disk remains in the drive. Take the disk out and your previously
 ASSIGNed fonts home directory is active  again. There is nothing to click,
 and nothing to type using  this  method.  You  can insert and remove disks
 with different collections of  fonts  to  use  in one single project using
 this trick.

      The danger in this method is that all fonts collection disks have the
 exact same name: "FONTS". If you  ever  forget and insert two disks of the
 exact same name, you confuse the operating  system and it has to go to the
 GURU to ask advice. Another important thing to remember is to put the disk
 in the drive BEFORE the system sends  out  for the list of fonts available
 in the fonts home directory. Notepad goes looking for fonts before it even
 gets to the opening screen of the  program,  so  the fonts disk must be in
 the drive already, or it will only  find  the  ROM fonts. DPaint loads the
 list when you select  "Load  Fonts  Dir"  from  the  fonts pull-down menu.
 PageSetter loads the fonts  list  when  you  select a document to edit, or
 select a box to create.

      To make your special fonts disks  you  need  to keep in mind that the
 DISK is acting as the fonts home  directory.  The  level of the disk where
 all  directories  start  is   called   the  root,  and  it  branches,  and
 sub-branches into what they call a tree structure. The dot-font files must
 be in the root.  They  cannot  be  in  any  directory  at  all.  The fonts
 themselves need to  have  their  directories  also  in  the  root, and the
 individual  font  sizes  datafiles  must  be  inside  their  correct  font
 directories as recorded  in  the  index  files.  This  is too much kluging
 around for the long  term,  but  it  solves  a  problem  in  the immediate
 present.

      To swap lists of fonts anytime is  not  possible  with most programs.
 Pagesetter loads only the requested fonts  and retains them continually in
 memory  until  free  memory  space  gets  cramped.  Even  after  you  exit
 PageSetter after working with some  fonts,  re-enter the program and start
 using a new set of fonts  from  another  disk  or  directory, the previous
 fonts remain available for use. With Deluxe  Paint II you load one list of
 fonts upon request and the only way  to  access another set of fonts is to
 use an undocumented feature hidden in the "Screen Format" selector. If you
 change bit-planes and/or  resolution  in  DPaint  II you flush all buffers
 including your custom brush, undo,  spare  screen, and your LIST OF FONTS!
 You can load a list of fonts from one disk, use some styles, and go select
 your currently selected screen  format,  and be able to load in a new list
 of fonts to keep adding to your painting.  Just clicking "OK" without even
 changing anything about the size  or  colors  of  your screen is enough to
 flush the buffers. (Be sure you've saved  any custom brush you want to use
 again, or it will be lost by doing this.)

      By the way, fonts do not use much CHIP RAM, if you have available RAM
 expansion memory. Only the  entry  for  the  font  attributes on a list is
 consumed, so you can keep lots of fonts in memory without interfering with
 other programs use of CHIP RAM.

      The Amiga Operating System version 1.2  and earlier have a feature to
 allow fonts which have once been used by any program to continue to remain
 in RAM without being deleted,  and  be  available  for  fast access by any
 other program running without reloading from disk. If loaded fonts are not
 actually being used by any  program  the  fonts  are deleted if there is a
 need to use the RAM memory. So it doesn't really hurt to leave them behind
 on program exit, and it may be a user-friendly thing to do. Unfortunately,
 some people with memory monitors  complain  that programs do not "free-up"
 all the memory they use upon  program  exit.  This is a bad reading of the
 true availability of the  memory  upon  any  programs genuine need, and it
 saves future font access time. Programmers should not necessarily cater to
 the "clean exit" crowd, because evidently these people have more free time
 in their lives to listen to their  floppy  disk  whir reloading data which
 could have harmlessly remained in  memory.  The  advantages of making fast
 exits of a program to do something  else,  and  re-running the program and
 finding all your fonts and font library  still remaining outweigh the joys
 of seeing bigger numbers on a memory monitor.  Pagesetter leaves the fonts
 behind, most other programs clean them out before exit.

      The fonts themselves are a series of pictures,  usually letters of an
 alphabet (the alphabet may be roman, greek, russian, hebrew, or scientific
 symbols, etc.), punctuation, numerals,  and other symbols. Each font comes
 in a single  size,  described  by  the  font  height  from  the top of the
 character space to the bottom  of  the  character  space.  The font may be
 fixed width, meaning every letter  gets  the  same number of units wide as
 every other letter. The  units  of  width  and  height  are  the pixel, or
 "Picture Element". The pixel  on  the  Amiga  may  be one of four possible
 sizes:  Low-res,   Interlace,   Med-res,   or  High-res.  Some  fonts  are
 specifically designed to look  correct  in a specific resolution mode, and
 may have the attribute  of  TALLDOT  or  WIDEDOT  in  the dot-font file to
 assist programs looking for  the  best  fonts  to  display in a particular
 resolution mode.

      The "point" is the term  for  the  pixel  dots.  It  derives from the
 centuries old typographer term  of  the  PICA  POINT,  or 1/72 of an inch.
 Modern dot-matrix printers using 24 pins produce 72 dots per inch, or pica
 points. The pixel  is  not  fixed,  however,  and  will  be  tall or wide,
 depending on the  currently  selected  resolution  mode.  So points on the
 screen will not correspond to points on paper printouts.

      First let's examine fonts on the  screen  so we can understand how to
 get our best printouts. Then we can  look  at  the alternative ways to get
 hardcopy with satisfactory results.

      Most Amiga DISK-fonts will be "proportional"  space fonts. This means
 every character will  get  the  portion  of  space  necessary to produce a
 correct looking character. The  lower  case  "i", the period ".", and some
 others will get little width  of  space  because  the need little. Capital
 letters, like "M", and "W", will get more space because they are naturally
 wider. These  characters  need  to  be  designed  this  way  when they are
 created. Some programs cannot  accept  proportional  width fonts, like CLI
 and NEWCLI, ED, EMACS, SCRIBBLE!, TEXTCRAFT, and many more. There are ways
 to force these programs to use proportional  fonts, but you can get pretty
 bizarre results if you do it.

      Fixed width fonts are  useful  in  programs  which  count  columns of
 characters, line up columns of figures (like a spreadsheet), and that sort
 of thing. Many programs do not use  any  fonts, per se, although you might
 ask "what the heck is that on my screen  then?". Programs interface to the
 user through terminals: an  input  terminal,  an  output  terminal, and an
 error terminal. These are "virtual"  terminals,  or  imaginary ideals, and
 are treated like files by the operating system. The system sends output to
 the screen as if it were storing  a  file  on  a screen-disk. It reads the
 keyboard like it was loading a file  in  from a keyboard-disk. It can just
 as easily read a file in from  RAM-disk  and  output it to the printer (or
 printer-disk). The program doesn't deal  with fonts in this case, only the
 screen-disk  translator  of  the  operating  system.  The  program  has no
 recognition of the existence of  fonts,  although the programmer must take
 them into account to some extent.  You  can  jam in a program to intercept
 the output going to the screen and replace the pictures of characters with
 your own font set of pictures of  each  character. SetFont does this, with
 occasionally troubling results.  Output  to  the printer is intercepted by
 the printer ROM and it  substitutes  its  own  pictures for each character
 received.

      The pictures of each character  on  the  screen  are stored on ROM or
 DISK as fonts, and the position of  the  current location of the cursor is
 used as the starting point of  the  place  to  draw  in the picture of the
 character. The screen is mapped,  with  the  top left corner of the screen
 being the usual starting point, and rows  are the lines of dots across the
 width of the screen,  while  columns  are  the  lines  of dots from top to
 bottom of the screen.  Counting  rows  and  columns  gives the location to
 begin drawing the character. This  is  called  "BIT MAPPED GRAPHICS". Each
 bit, or pixel dot is mapped to one  unique  location on the overall screen
 or window.

      ROM-fonts and DISK-fonts are  bitmaps.  There  is a picture somewhere
 used as the master that is copied to the position each time. Normally font
 bitmaps are not compressed, or compacted, in any way, and may use a lot of
 memory to store the collections of  pictures  which  make up a large font.
 The theoretical limit on the maximum  size  of a font is 16 megabytes, but
 more practically 5,000,000 bytes is the  limit with existing font creation
 tools. This ultimate size would  require  a  hard drive to store the font,
 and of course RAM expansion to load it in. I make fonts larger than can be
 used on a 512K Amiga, and problems can  result with programs which are not
 written to allow space to load and use several large fonts.

      The Amiga uses the monitor as a  viewing  window into RAM memory, and
 the bitmapped graphic screen can  be  much  larger  than the video viewing
 area. Page make-up programs,  and  some  paint  programs do this. You will
 only see the the part of the whole  bitmap  which appears on your monitor,
 although you can scroll around to see the hidden parts.

      Your resolution mode will determine how  many rows and columns of the
 bitmap will be visible at any instant.  In high resolution you can see 640
 columns of pixels in the  normal  viewing  window.  In interlaced mode you
 will see 400 rows of pixels. It uses  more  hardware resources to view 640
 columns of  pixels, so that restricts  your number of colors to a limit of
 16. In low resolution you can get 32, or upto 4096 colors.

      Desktop publishing (or page  make-up)  software  usually uses the 640
 pixel wide mode to fit more information  into the width of the screen, and
 usually uses non-interlace to  avoid  the  bothersome  screen jitter. Most
 programs also use a limit on  the  colors  to  4 or 2, to make more memory
 available to the  page  displays.  This  is  usually  chosen because color
 printers are not as  available  to  the  users,  and  mass reproduction is
 usually done by black and white lithography or xerography.

      A 24 pin dot matrix printer produces 960 dots per 8 inch wide line of
 printout. If your page is  not  exactly  960  dots  wide on your bitmapped
 graphic screen, then there  will  not  be  a  one-to-one correspondence of
 printed dots to screen dots. "Scaling"  will have to be performed. If your
 bitmap is 320 dots wide then  exactly  3  dots wide will be printed out to
 represent each one dot on your  dot-matrix  printer. If your bitmap is 640
 dots wide then you will need to print  out 1.5 dots on paper for every dot
 on the graphic bitmap. Printers cannot print half a dot, however. Printers
 can only print or not print a dot,  so  the  program either prints out the
 image  640  dots  wide  as  a   2/3rds   wide   image  with  a  one-to-one
 correspondence, or it prints every  other  dot  twice and the intermediate
 dots once. This fattens some columns  of  the print out and not others. It
 can be  minimal  in  effect  or  ruinous,  depending  on  your  degree  of
 perfectionism.

      Scaling is even more difficult to  predict  if  your bitmap is an odd
 size in width, say 723 pixels  wide.  You  will  not get WYSIWYG, and will
 have to test print it to determine  if  your result will be acceptable for
 your needs.

      Page make-up programs take this into  account,  and usually provide a
 page width that corresponds to 24 pin printer lines.

      None of the bitmap can be  successfully  printed  unless your printer
 supports a graphics mode to accept  screen  dumps.  Which brings us to the
 subject of printer drivers and  preferences.  The system dumps graphics to
 the selected printer port, either parallel  or serial, as if it was saving
 to  a  disk.  The  printer  driver   reads  your  preferences  and  prints
 accordingly. So preferences must be adjusted to match your desired output.

      Deluxe Paint II loads up  your  preferences  file,  but allows you to
 over-ride this at print time through a requestor window. You may decide to
 print in grayscale even  if  your  preferences  are  set  to color or B&W.
 Pagesetter on the other hand refuses  to  print if preferences are not set
 to B&W, even though my printer produces better blacks if I print out using
 the color preference!

      The third screen back in the  preferences  program determines if your
 bitmap printout will  be  printed  sideways  or  normal  horizontal. Again
 scaling is performed to translate the  number of dots in the bitmap to the
 number of dots in the printout for  sideways  printing,  usually expanding
 the dots considerably.  The  threshold  value  determines if light colored
 dots will be ignored, and skipped,  printing  as  "white", or whether they
 will be printed dark, even  as  full  black.  You  really  need to do some
 experimentation here to find you favorite, but PageSetter requires that it
 be set at 2 or 3 for the default page settings.

      The width and height of the bitmap  printout  will be affected by the
 settings for your margins with some  printers,  and  not at all for others
 which ignore margin settings. The number  of lines per inch, and number of
 characters per inch settings will  affect  the scaling done by the printer
 drive, in addition to  any  scaling  done  by  the  program  producing the
 bitmap. It is best to set  for  6  lines  per  inch  (lpi) and 10-pica for
 pitch. Let the program alone  do the scaling, unless you need reduced size
 miniature printouts, then let  preferences  do  additional scaling through
 the  printer-driver.  Experimentation  with  a  variety  of programs and a
 variety of bitmaps is the  best  thing  you  can do to get predictable and
 consistent outputs.

      Fixed width fonts are  pretty  simple  things.  Each  character has a
 rectangle of space  for  the  font  artist  to  draw  the  picture  of the
 character. Any space between characters must be left in by the artist. The
 program which displays the pictures may use destructive techniques to copy
 each character into position.  This  means  that  the invisible background
 color may erase anything already  drawn  in the position the new character
 copy occupies as a rectangle. They may  also be non-distructive, in that a
 character may overlap some  previously  drawn picture or character without
 erasing the portion of  the  new  character  drawn  with  the  transparent
 background color.

      Programs which do not use fonts normally produce distructive lines of
 text obliterating the area  underneath  their image in rectangular blocks.
 Programs designed to use  fonts  normally  let  you overlay text on top of
 previous images.  Proportional  width  fonts  include  factors which allow
 non-distructive overlap of characters on each other, for special purposes.
 There are settings which are  adjustable  for  each and every character of
 the font which determines how closely  it will fit to the character before
 it and how closely the one to follow will be placed.

      Kern is the typographers term for  precise  fitting of a character to
 the one to the left of it.  There  are  character  pairs which look odd or
 incorrect if they use the same  distance  between  them as they do between
 other characters.

      I  must  digress  a  moment  before   continuing  on  Amiga  specific
 typography to  cover  general  computerized  typography.  For  more than a
 decade there have been microprocessor controlled typography work stations.
 The microprocessors employed have been 8-bit devices, with only 16, 48, or
 64 kilobytes of memory to run them.  In  other words, these very expensive
 machines have had the equivalent of an  Apple II, a Radio Shack TRS-80, or
 a Commodore-64 as the "brains" of  these  work stations. The major part of
 the expensiveness has been  the  back-end,  or  the  type fonts on wheels,
 drums, and film strips, and the  positioning  and exposure mechanisms. The
 computer part  is  relatively  simple  and  cheap.  These  devices produce
 "leading",  "reverse-leading",  "kerning",   "discretionary  hyphenation",
 "auto-hyphenation",   "letter-spacing",   "justification",  "flush  left",
 "flush  right",  and  other   features.   Twelve  years  ago  CompuGraphic
 Corporation wanted to sell me the ExecuWriter  desktop typesetting machine
 for a retail price of $2000, which  could  produce  output far superior to
 any laser printer now selling  at  any  price.  So if I seem to be annoyed
 that Amiga programmers are not  always  providing all the features which I
 expect, and which  the  Amiga  operating  system  provides  handy tools to
 easily implement, perhaps  you'll  forgive  my  impatience. These problems
 were solved in software long ago!

      Kerning usually involves a look-up table of about 300 pairs of letter
 combinations.  Each  time  the  computer  program  detects  one  of  these
 combinations it replaces  the  picture  of  two separate characters with a
 single picture of  two  characters  combined.  Amiga  kerning  involves  a
 positive or  negative  number  of  points  where  the  left  edge  will be
 positioned relative to the  cursor  current  position.  This does not take
 into account any previous character, or even if there is one there at all.
 If a letter with a kern number of 3 is at the left margin it will be drawn
 3 pixels off the left side of the screen  and only the part showing on the
 screen will be drawn visibly. This is not very useful for most characters,
 and really is only  useful  for  special  foreign  language  symbols,  and
 scientific or mathematical symbols which  must be composed of parts joined
 together. The kern amount is individually adjustable for each character in
 a font, and only applies to proportional width fonts.

      The kern affects the left edge of the  character. The character width
 affects the amount of space  from  the  left  edge  to the right edge, and
 determines how much space exists to contain  the picture of the character.
 Again this is only used in proportional fonts, and is individually set for
 each character. On the  right  side  of  the  character  there is a factor
 called "space". This is not in any way  related to the blank character you
 get if you press the  keyboard  spacebar.  The  space  character is a font
 character just like every other character,  and just has all pixels in the
 picture drawn in the background  color.  It has a definite width just like
 all other characters, and it has  "space"  just  like all other characters
 which may ne included in a  font.  What  character  "space" is is a factor
 setting for each character which determines where the cursor position will
 be placed at the end of drawing the character. Space will affect where the
 next character's left edge  starts,  and  will  be  factored in with other
 items such as kern.

      So kern, width, and space all  combine  to  determine how a character
 will fit inside a word relative to the characters on each side of it, each
 with their own possibly unique kern, width, and space.

      In Guttenberg's time of setting type  using  physical characters cast
 in metal to be re-usable, there was  no  such  thing as "reverse-leading".
 Two physical objects could not occupy the same space, so each line (or row
 as we call it) had to be a  minimum  distance  from  the previous and next
 line. You could  increase  the  space  between  lines  by  adding physical
 objects to add separation, and what they  did was use metal which could be
 hammered very thin: the metal lead. These  additional points of separation
 between lines of text became known as points of leading, and were measured
 in pica points (72 per  inch).  With  photo-typesetting  and  computerized
 video fonts came  the  possibility  of  some  overlap  between  the bottom
 decenders of characters  (like  gjpqy;,)  with  the  top of the next line,
 since it was no  longer  physical  objects.  Reverse-leading  and  leading
 permitted columns of lines of type  to  be squashed or stretched to better
 fill an exact allotment of vertical column  space. This is often necessary
 when the amount of  words  does  not  fit  in  the  limit  of the physical
 printout space for it. With the  Amiga,  points  of leading are pixels and
 cannot be sub-divided  into  half  points  like  you  can  for typography,
 although points are resolution dependent  and will vary if interlace is on
 or not.

      Amiga fonts get a uniform number of rows, or height in pixels for the
 letters to exist within.  All  letters  of  a  font have the same vertical
 height, but the characters do not need  to be all the same size within the
 font. Fonts are stored in their  directory,  and  named by height size, so
 the newest creation always destroys the datafile of the previous font with
 the same name as a point size. It is possible  to store more than one font
 in the same size  if  the  fontname  has  an  extension  prefix,  but many
 programs only expect one font per  size,  and  may list all the font sizes
 with their prefixes, but only load the first occurrence they find with the
 size prefix requested. In  other  words,  other  choices  may be there but
 totally inaccessible with your program.

      Unless the program provides user over-ride of the height factor, each
 line of text begins  precisely  at  the  next  pixel  down  from where the
 previous one left off.  If  there  was  user  control  it  might be called
 "leading" (pronounced LEDing), or "line spacing" or such.

      Programs which allow  mixing  different  fonts  on a line of text are
 rare, and there may be  three  ways  they  determine  how  to position the
 character: by the top-left corner of  the  font, by the bottom-left corner
 of the font, or by the left side and  the  baseline. This opens up an area
 of confusion for programmers because  there  is no standard from Commodore
 or the industry, so there is now way  for  font artists to design fonts to
 be usable the same across all programs  which mix fonts. The baseline is a
 global factor of a font,  like  the  height,  which  is  the  same for all
 characters in a font.

      The font need not be drawn on a  baseline,  for example, a font which
 provides  superscript  and   subscript  character  options  may  have  the
 characters drawn above and below  the  baseline.  But the baseline will be
 the same distance in rows from the top  for every character. Underlining a
 font with subscripts  may  have  the  underline  pass  right  through  the
 subscript characters instead of under  them. Software underlining uses the
 baseline to determine where the  underline  should  be placed. It is a one
 point tall line  the width of the character two pixels below the baseline.
 fonts created with the baseline  at  the  bottom  of  the font height will
 crash the system when software  underlining  is  selected. It will corrupt
 memory below the area the character pictures occupy.

      The baseline is used as  the  point  where  all  the  capital letters
 ascend from. Other typographers terms you may encounter are the "x-height"
 of the letters  is  the  uniform  height  of  lower  case  letters without
 ascenders. "Ascenders" are  those  parts  of  lower  case letters which go
 above the x-height (like bdfhijklt). Decenders  were previously described.
 Incidentally, printers using  pieces  of  reusable  characters cast out of
 metal kept them in  large  cabinets  of  shelves  of  slide-out trays. The
 letters we call "capital" letters were  kept in the top tray, or case, and
 the one below it held the smaller  letters  or lower-case. Here's where we
 get the still used terms for the  big  and  small letters of the alphabet:
 UPPER CASE and lower case.

      A recently invented form of Amiga DISK-fonts are COLORFONTS. This was
 invented by Inter/Active  Softworks  of  San  Francisco, California. Their
 Calligrapher program is  a  font  editor  which  allows  you to create and
 modify standard Amiga  DISK-fonts,  and  to  control every aspect of every
 character in your fonts.

      With the introduction of the CALLIGRAPHER  they introduced a new type
 of Amiga DISK-font which allows 16 colors  per font. These colorfonts have
 been designated a new IFF type  by  CBM,  and  the  code to activate these
 colorfonts in all  programs  using  DISK-fonts  will  be  included  in the
 proposed 1.3 version of the Amiga  Operating  System. In the meanwhile new
 Amiga programs are including  the  code  to  activate  colorfonts, and the
 first such program to arrive on the market  was PRISM, a HAM paint program
 from Impulse. Calligrapher and other products  from Inter/Active Softworks
 include a temporary  patch  program  called  "COLORTEXT"  to  allow use of
 colorfonts in all programs  which  allow  both  color and disk-fonts to be
 used. The Calligrapher is a low cost  font  editor selling very well and I
 expect a lot of public  domain  color  fonts,  as  well as many commercial
 color fonts produced  by  fine  artists  to  be  available  for your Amiga
 pleasure.

      Page make-up programs which restrict the  user to B&W will not permit
 use of  colorfonts,  and  attempts  to  use  them  will  be  ugly failure.
 Professional Page by Gold Disk  (PageSetter),  and Shakespeare by Infinity
 Software (Grand Slam Tennis,  Gallileo)  are two products being readied to
 do color page make-up which will allow use of colorfonts.

      The COLORTEXT patch  will  not  be  needed  by  these  new  programs.
 COLORTEXT is copyrighted, and may  not  be  redistributed.  At the present
 time it is limited to being obtained from Inter/Active Softworks products,
 and I have a  license  to  include  it  on  my  "Lion's  Amiga Art Studio"
 products. There is a public  domain  version  of  colortext  which shows a
 preview of what you would see, excepting it eliminates the vowels AEIOU in
 the display, and this  demo  version  is  freely  available  through users
 groups and BBSs.

      Other Amiga fonts to mention, for completeness  sake, are PFonts from
 Sparta, and Stroke font from Aegis. The  PFont is a polygon font structure
 describing a logo-like, or  turtle-graphic  type of font which is scalable
 on the screen, and may be  stretched  or  squashed  at will. It is used in
 Aegis VideoTitler  product.  A  similar  concept  of  font  is included as
 objects on the Aegis Videoscape-3D disk  as separate characters in 3D. The
 stroke font is used in  Aegis  Draw  CAD  program  and  is  one pixel wide
 strokes making the letters which is scalable  depending on your zoom view.
 Ultimately these are all dumped to  printer  as  bitmap representations of
 the screen bitmap, and suffer all the  scaling problems in hardcopy as the
 others. Draw however supports pen  plotters  which can correctly reproduce
 the stroke font.

      TEX is  a  device  independent  font  system,  which  adapts  to  the
 particular limitations of the  Amiga  display,  and  is also output device
 independent to the extent that it can be output to a number of devices and
 give  approximately  similar   output   on  plotter,  printer,  laser,  or
 phototypesetter. If output to dot-matrix it again suffers every limitation
 of every other type of font in the scaling of pixels to printer dots.

      Postscript is a  page  description  language.  It  is  widely used in
 desktop make-up programs  on  other  computers,  and  there  is  LaserPage
 (PageSetter), and City Desk for the Amiga which produce output files which
 can  be  directly  sent   by   cable   or   modem  to  laser  printers  or
 photo-typesetting  machines   which   support   the  PostScript  language.
 PostScript is  another  language  that  is  turtle-graphics  like  in its'
 construction of each character of the alphabet, and is device independent.
 There is much debate as to  whether  PostScript  is  the best of many Page
 Description Languages, but it was adopted  early on by Apple for the Apple
 LaserWriter printer, and is very  popular  now. With PostScript you cannot
 truly  preview  what  you   will  see  on  the  output,  but  you  get  an
 approximation on the screen bitmap.  Special  bitmap  Amiga disk-fonts are
 used to fill in the lines of type  with  something  which looks similar to
 the output type  fonts  the  PostScript  device  will  produce.  There are
 serious errors in how much width lines  of type will need, and in how much
 vertical column space will be  filled  by  the final text printout. Here's
 another example of a place where  much  experimentation  will finally make
 you an expert.

      Laser  printers  use  a  laser   diode   device  to  demagnetize  the
 non-printing areas of a xerography drum. The printing is done like regular
 xerography, and the image detail is  limited  to  about 300 dots per inch.
 That is 300 dots per inch wide times  300  dots per inch tall, for a total
 of 90,000 dots to print a 1 inch  black  square.  This is about four times
 more  detail  resolution  than  dot  matrix,  but  only  about  1/4th  the
 resolution of the cheaper photo  typesetting  machines. For people who are
 used to office  typewriters  and  office  xerography  machines  this  is a
 wonderful improvement. For typographers this is proof copy, unsuitable for
 ever showing the the public proudly.

      Amiga owners with dot printers  with  square  dots,  which print in a
 good dense black image can get laser  quality  images by printing out four
 times larger than their final image  size  and  reducing the image at your
 local copy shop. As you reduce  the  image  the  jaggie stairstep dots are
 similarly reduced. A 25% reduction  will  give  you a final image of 1/4th
 size. Your 72 dots per  inch  will  now  be  288  dots per inch. The final
 output from a cheap xerography reduction will be the same as for the laser
 printer since they both use xerography  to get the black on the paper. Low
 cost xerography  copiers  usually  have  a  setting  at  64% minimum and a
 reduction of a reduction will end up 42%  size. This should be plenty good
 enough to impress anyone who  finds  a  laser  printout  impressive. Laser
 printers are fast, quiet, and cheap  per  page spread out over the life of
 the unit. Most Amigas  can  only  justify  a  dot  printer  on the desktop
 however, and this is a good cheap  alternative  to  the high cost of laser
 printing.

      One other point should be mentioned: the stock laser fonts were never
 designed to be used in  tiny  text  sizes.  They  were  designed by master
 typographers each for  specific  purposes  and  hired  to do this by major
 institutions. Nobody ever hired or paid   anyone to design any fonts which
 would be readable and easily comprhensible  by readers especially to match
 the limitations of the  laser  printer.  There  is a lot of disrespect for
 professional type designers, and it is  not understood what is involved in
 the process. The typefont used  in  printing  your  Bell Yellow Pages took
 four years, and was not  designed  for  any  other  purpose or use. It was
 designed to match the size needed by the  customer and survive the hazards
 of printing ink on thin sheets of paper  with showthru from the other side
 of  the  page.  Certain   aspects   of  the  characters  are  deliberately
 exaggerated to make the  words  easier  to  read in cramped lines of type.
 Another case is Herman Zapf who is a famed designer of some of the world's
 most used typefaces took seven  years  to  complete the design of "Melior"
 font. Here is a man who has created many fonts over a long lifetime career
 of being a typographer, yet wasn't satisfied  with all aspects of it until
 longer than the lifetime of the the Apple laserWriter.