command.hh

   1 #ifndef COMMAND_HH
   2 #define COMMAND_HH
   3 #include "glob.hh"
   4 #include "mtime.hh"
   5 #include "vray.hh"
   6 enum Commandcode {
   7         NOP,
   8         INTERPRET,
   9         TYPESET,
  10         BREAK_PRE,BREAK_MIDDLE, BREAK_POST, BREAK_END,
  11 };
  12 /// set a nonrythmical symbol
  13 struct Command {
  14     Commandcode code;
  15
  16     Mtime when;
  17     /// analogous to argv[]
  18     svec<String> args;
  19 };
  20
  21 /**
  22     A nonrhythmical "thing" in a  staff is called a "command".
  23     Commands have these properties:
  24
  25     \begin{itemize}
  26     \item They are \bf{not} rhythmical, i.e. they do not have  a duration
  27     \item They have a staff-wide impact, i.e. a command cannot be targeted at
  28     only one voice in the staff: two voices sharing a staff can't have
  29     different clefs
  30     \item Commands are ordered, that is, when from musical point of view the
  31     commands happen simultaneously, the order in which Staff receives the
  32     commands can still make a difference in the output
  33     \item Some commands are actually score wide, so Score has to issue these
  34     commands to the Staff, eg. BREAK commands
  35     \end{itemize}
  36
  37     At this moment we have three classes of commands:
  38     \begin{description}
  39     INTERPRET commands are not grouped.
  40     \item[TYPESET] These commands instruct the Staff to
  41     typeset symbols on the output, eg meter/clef/key changes
  42     \item[INTERPRET] These commands do not produce output, instead,
  43     they change the interpretation of other commands or requests.
  44     example: shift output vertically, set the key.
  45     \item[BREAK_XXX] These commands group TYPESET commands in
  46     prebreak and postbreak commands. \See{Col}.
  47     Staff can insert additional commands in a sequence of BREAK_XXX
  48     commands, eg. key change commands
  49
  50     \end{description}
  51
  52     These commands are generated by Score, since they have to be the
  53     same for the whole score.
  54
  55
  56     \begin{description}
  57     \item[BREAK_PRE]
  58     \item[BREAK_MIDDLE]
  59     \item[BREAK_POST]
  60     \item[BREAK_END]
  61     \item[TYPESET] METER,BAR
  62     \end{description}
  63
  64
  65     Commands can be freely copied, they do not have virtual methods.
  66     */
  67
  68
  69 #endif