Provided by: sgt-puzzles_9411-1_i386 bug

NAME

       towers - puzzle game based on Skyscrapers

SYNOPSIS

       towers  [--generate  n]  [--print  wxh  [--with-solutions]  [--scale n]
       [--colour]] [game-parameters|game-ID|random-seed]

       towers --version

DESCRIPTION

       You have a square grid. On each square of the  grid  you  can  build  a
       tower,  with  its height ranging from 1 to the size of the grid. Around
       the edge of the grid are some numeric clues.

       Your task is to build a tower on every square, in such a way that:

       +o      Each row contains every possible height of tower once

       +o      Each column contains every possible height of tower once

       +o      Each numeric clue describes the number of  towers  that  can  be
              seen  if  you look into the square from that direction, assuming
              that shorter towers are hidden behind taller ones. For  example,
              in  a  5x5 grid, a clue marked '5' indicates that the five tower
              heights must appear in increasing order (otherwise you would not
              be  able  to  see  all  five  towers), whereas a clue marked '1'
              indicates that the tallest tower (the one marked  5)  must  come
              first.

       In  harder  or larger puzzles, some towers will be specified for you as
       well as the clues round the edge, and some edge clues may be missing.

       This puzzle appears  on  the  web  under  various  names,  particularly
       'Skyscrapers', but I don't know who first invented it.

Towers controls

       Towers shares much of its control system with Solo, Unequal and Keen.

       To  play  Towers,  simply  click the mouse in any empty square and then
       type a digit on the keyboard to fill that square with a  tower  of  the
       given  height.  If you make a mistake, click the mouse in the incorrect
       square and press Space to clear it again (or use the Undo feature).

       If you right-click in a square and then type a number, that number will
       be  entered in the square as a 'pencil mark'. You can have pencil marks
       for multiple numbers in the same square. A square  containing  a  tower
       cannot also contain pencil marks.

       The  game  pays  no  attention to pencil marks, so exactly what you use
       them for is up to you: you can use them as reminders that a  particular
       square  needs  to  be re-examined once you know more about a particular
       number, or you can use them as lists of the possible numbers in a given
       square, or anything else you feel like.

       To  erase  a single pencil mark, right-click in the square and type the
       same number again.

       All pencil marks in a square are erased when you left-click and type  a
       number,  or  when  you  left-click  and press space. Right-clicking and
       pressing space will also erase pencil marks.

       As for Solo, the cursor keys can be used in conjunction with the  digit
       keys  to  set  numbers  or  pencil marks. Use the cursor keys to move a
       highlight around the grid,  and  type  a  digit  to  enter  it  in  the
       highlighted  square.  Pressing return toggles the highlight into a mode
       in which you can enter or remove pencil marks.

       Pressing M will fill in a full set of pencil marks in every square that
       does not have a main digit in it.

       (All the actions described below are also available.)

Towers parameters

       These  parameters  are  available  from  the  'Custom...' option on the
       'Type' menu.

       Grid size
              Specifies the size of the grid. Lower limit is 3; upper limit is
              9  (because  the user interface would become more difficult with
              'digits' bigger than 9!).

       Difficulty
              Controls the difficulty of the generated puzzle. At Unreasonable
              level,  some  backtracking  will  be  required, but the solution
              should  still  be   unique.   The   remaining   levels   require
              increasingly complex reasoning to avoid having to backtrack.

Common actions

       These  actions  are all available from the 'Game' menu and via keyboard
       shortcuts, in addition to any game-specific actions.

       (On Mac OS X, to conform with local  user  interface  standards,  these
       actions are situated on the 'File' and 'Edit' menus instead.)

       New game ('N', Ctrl+'N')
              Starts a new game, with a random initial state.

       Restart game
              Resets  the  current  game  to  its  initial state. (This can be
              undone.)

       Load   Loads a saved game from a file on disk.

       Save   Saves the current state of your game to a file on disk.

              The Load and Save operations preserve your entire  game  history
              (so you can save, reload, and still Undo and Redo things you had
              done before saving).

       Print  Where supported (currently only on Windows), brings up a  dialog
              allowing  you  to  print an arbitrary number of puzzles randomly
              generated from the current parameters, optionally including  the
              current  puzzle. (Only for puzzles which make sense to print, of
              course  -  it's  hard  to  think   of   a   sensible   printable
              representation of Fifteen!)

       Undo ('U', Ctrl+'Z', Ctrl+'_')
              Undoes  a  single move. (You can undo moves back to the start of
              the session.)

       Redo ('R', Ctrl+'R')
              Redoes a previously undone move.

       Copy   Copies the current state of your game to the clipboard  in  text
              format,  so that you can paste it into (say) an e-mail client or
              a web message board if you're discussing the game  with  someone
              else. (Not all games support this feature.)

       Solve  Transforms  the puzzle instantly into its solved state. For some
              games (Cube) this feature is not supported at all because it  is
              of  no  particular  use.  For other games (such as Pattern), the
              solved state can be used to give you information, if  you  can't
              see  how  a  solution can exist at all or you want to know where
              you made a mistake. For still other  games  (such  as  Sixteen),
              automatic  solution  tells  you  nothing about how to get to the
              solution, but it does provide a useful way to get there  quickly
              so   that   you   can   experiment   with  set-piece  moves  and
              transformations.

              Some games (such as Solo) are capable of solving a game  ID  you
              have  typed  in from elsewhere. Other games (such as Rectangles)
              cannot solve a game ID they didn't  invent  themself,  but  when
              they  did  invent  the  game  ID  they know what the solution is
              already. Still other games (Pattern)  can  solve  some  external
              game IDs, but only if they aren't too difficult.

              The 'Solve' command adds the solved state to the end of the undo
              chain for the puzzle. In other words, if you want to go back  to
              solving  it yourself after seeing the answer, you can just press
              Undo.

       Quit ('Q', Ctrl+'Q')
              Closes the application entirely.

Specifying games with the game ID

       There are two ways to save a game specification out  of  a  puzzle  and
       recreate  it  later, or recreate it in somebody else's copy of the same
       puzzle.

       The 'Specific' and 'Random Seed' options from the 'Game' menu  (or  the
       'File' menu, on Mac OS X) each show a piece of text (a 'game ID') which
       is sufficient to reconstruct precisely the same game at a later date.

       You can enter either of these pieces of text back into the program (via
       the  same  'Specific'  or 'Random Seed' menu options) at a later point,
       and it will recreate the same game. You can also use either  one  as  a
       command line argument (on Windows or Unix); see below for more detail.

       The difference between the two forms is that a descriptive game ID is a
       literal description of the initial state of the game, whereas a  random
       seed  is  just a piece of arbitrary text which was provided as input to
       the random number generator used to create the puzzle. This means that:

       +o      Descriptive game IDs tend to be longer in many puzzles (although
              some,   such   as   Cube   (cube(6)),   only   need  very  short
              descriptions). So a random seed is often a quicker way  to  note
              down  the  puzzle  you're  currently  playing,  or to tell it to
              somebody else so they can play the same one as you.

       +o      Any text at all  is  a  valid  random  seed.  The  automatically
              generated  ones are fifteen-digit numbers, but anything will do;
              you can type in your full name, or a word you just made up,  and
              a  valid  puzzle  will be generated from it. This provides a way
              for two or more people to race to complete the same puzzle:  you
              think  of  a random seed, then everybody types it in at the same
              time, and nobody  has  an  advantage  due  to  having  seen  the
              generated puzzle before anybody else.

       +o      It is often possible to convert puzzles from other sources (such
              as 'nonograms' or 'sudoku'  from  newspapers)  into  descriptive
              game IDs suitable for use with these programs.

       +o      Random  seeds  are  not guaranteed to produce the same result if
              you use them with a different version  of  the  puzzle  program.
              This  is  because  the  generation  algorithm  might  have  been
              improved or modified in later versions of  the  code,  and  will
              therefore  produce  a  different  result  when  given  the  same
              sequence of random numbers. Use a descriptive  game  ID  if  you
              aren't  sure  that  it  will  be used on the same version of the
              program as yours.

              (Use the 'About' menu option to find out the version  number  of
              the  program.  Programs  with the same version number running on
              different platforms should still be random-seed compatible.)

       A descriptive game ID starts with a piece of  text  which  encodes  the
       parameters  of  the  current  game (such as grid size). Then there is a
       colon, and after that is the description of the game's initial state. A
       random  seed  starts  with  a similar string of parameters, but then it
       contains a hash sign followed by arbitrary data.

       If you enter a descriptive game ID, the program will  not  be  able  to
       show  you the random seed which generated it, since it wasn't generated
       from a random seed. If you enter a random seed,  however,  the  program
       will  be  able  to  show  you the descriptive game ID derived from that
       random seed.

       Note that the game parameter strings are not always  identical  between
       the  two  forms.  For some games, there will be parameter data provided
       with the random seed which is not included in the descriptive game  ID.
       This  is  because  that  parameter  information  is  only relevant when
       generating puzzle grids, and is not important when playing them.  Thus,
       for example, the difficulty level in Solo (solo(6)) is not mentioned in
       the descriptive game ID.

       These additional parameters are also not set permanently if you type in
       a  game  ID.  For  example,  suppose  you  have  Solo set to 'Advanced'
       difficulty level, and then a friend wants your help  with  a  'Trivial'
       puzzle;  so  the  friend  reads  out a random seed specifying 'Trivial'
       difficulty, and you type it in. The program will generate you the  same
       'Trivial'  grid which your friend was having trouble with, but once you
       have finished playing  it,  when  you  ask  for  a  new  game  it  will
       automatically  go  back  to  the  'Advanced'  difficulty  which  it was
       previously set on.

The 'Type' menu

       The 'Type' menu,  if  present,  may  contain  a  list  of  preset  game
       settings.  Selecting one of these will start a new random game with the
       parameters specified.

       The 'Type' menu may also contain a 'Custom' option which allows you  to
       fine-tune  game  parameters.  The  parameters available are specific to
       each game and are described in the following sections.

Specifying game parameters on the command line

       (This section does not apply to the Mac OS X version.)

       The games in this collection deliberately do not ever save  information
       on  to  the computer they run on: they have no high score tables and no
       saved preferences. (This is because I expect at least  some  people  to
       play them at work, and those people will probably appreciate leaving as
       little evidence as possible!)

       However, if you do want to arrange for one of these games to default to
       a  particular  set  of  parameters, you can specify them on the command
       line.

       The easiest way to do this is to set up the parameters you  want  using
       the  'Type' menu (see above), and then to select 'Random Seed' from the
       'Game' or 'File' menu (see above). The text in the 'Game ID'  box  will
       be composed of two parts, separated by a hash. The first of these parts
       represents the game parameters (the  size  of  the  playing  area,  for
       example, and anything else you set using the 'Type' menu).

       If  you run the game with just that parameter text on the command line,
       it will start up with the settings you specified.

       For example: if you run Cube (see cube(6)),  select  'Octahedron'  from
       the  'Type'  menu, and then go to the game ID selection, you will see a
       string of the form 'o2x2#338686542711620'. Take only  the  part  before
       the  hash  ('o2x2'), and start Cube with that text on the command line:
       'cube o2x2'.

       If you copy the entire game ID on to the command line,  the  game  will
       start  up in the specific game that was described. This is occasionally
       a more convenient way to start a particular game ID than by pasting  it
       into the game ID selection box.

       (You  could  also  retrieve  the  encoded  game  parameters  using  the
       'Specific' menu option instead of 'Random Seed', but  if  you  do  then
       some  options,  such  as the difficulty level in Solo, will be missing.
       See above for more details on this.)

Unix command-line options

       (This section only applies to the Unix port.)

       In addition to being able to specify game  parameters  on  the  command
       line (see above), there are various other options:

       --game

       --load These  options  respectively  determine whether the command-line
              argument is treated as specifying game parameters or a save file
              to  load.  Only  one  should  be  specified. If neither of these
              options is specified, a guess is made based on the format of the
              argument.

       --generate n
              If   this  option  is  specified,  instead  of  a  puzzle  being
              displayed, a number of descriptive game IDs will be invented and
              printed on standard output. This is useful for gaining access to
              the game generation algorithms  without  necessarily  using  the
              frontend.

              If  game parameters are specified on the command-line, they will
              be used to generate the game IDs; otherwise  a  default  set  of
              parameters will be used.

              The  most  common  use  of  this  option  is in conjunction with
              --print, in which case its behaviour is slightly different;  see
              below.

       --print wxh
              If   this  option  is  specified,  instead  of  a  puzzle  being
              displayed, a printed representation  of  one  or  more  unsolved
              puzzles is sent to standard output, in PostScript format.

              On  each  page of puzzles, there will be w across and h down. If
              there are more puzzles than wxh, more  than  one  page  will  be
              printed.

              If  --generate  has  also  been specified, the invented game IDs
              will be used to generate the printed output. Otherwise,  a  list
              of  game  IDs  is  expected  on  standard  input  (which  can be
              descriptive or random seeds; see  above),  in  the  same  format
              produced by --generate.

              For example:

              net --generate 12 --print 2x3 7x7w | lpr

              will  generate  two  pages of printed Net puzzles (each of which
              will have a 7x7 wrapping grid), and pipe the output to  the  lpr
              command,  which  on  many  systems  will  send them to an actual
              printer.

              There are various  other  options  which  affect  printing;  see
              below.

       --save file-prefix [ --save-suffix file-suffix ]
              If   this  option  is  specified,  instead  of  a  puzzle  being
              displayed, saved-game files for one or more unsolved puzzles are
              written  to  files  constructed  from the supplied prefix and/or
              suffix.

              If --generate has also been specified,  the  invented  game  IDs
              will  be  used to generate the printed output. Otherwise, a list
              of game  IDs  is  expected  on  standard  input  (which  can  be
              descriptive  or  random  seeds;  see  above), in the same format
              produced by --generate.

              For example:

              net --generate 12 --save game --save-suffix .sav

              will  generate  twelve  Net  saved-game  files  with  the  names
              game0.sav to game11.sav.

       --version
              Prints version information about the game, and then quits.

       The following options are only meaningful if --print is also specified:

       --with-solutions
              The  set  of pages filled with unsolved puzzles will be followed
              by the solutions to those puzzles.

       --scale n
              Adjusts how big each puzzle is when printed. Larger numbers make
              puzzles bigger; the default is 1.0.

       --colour
              Puzzles  will  be  printed  in  colour, rather than in black and
              white (if supported by the puzzle).

SEE ALSO

       Full documentation in /usr/share/doc/sgt-puzzles/puzzles.txt.gz.