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Diffstat (limited to 'Documentation/breaking')
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diff --git a/Documentation/breaking b/Documentation/breaking new file mode 100644 index 0000000000..ea1ada7e10 --- /dev/null +++ b/Documentation/breaking @@ -0,0 +1,38 @@ +[Source files: command.hh, scommands.cc] + +BREAKING, PREBREAK POSTBREAK, etc. + +So what's the deal with PREBREAK and POSTBREAK and all this +stuff? + +Let's take text as an example. In German some compound +words change their spelling if they are broken: "backen" becomes +"bak-ken". TeX has a mechanism to deal with this, you would define +the spelling of "backen" in TeX in this way + + \discretionary{bak-}{ken}{backen} + +These 3 arguments are called "prebreak", "postbreak" and "nobreak" +text. + +The same problem exists when typesetting music. If a line of music is +broken, the next line usually gets a clef. So in TeX terms, the clef +is a postbreak. The same thing happens with meter signs: Normally the +meter follows the bar. If a line is broken at that bar, the bar along +with the meter stays on the "last" line, but the next line also gets a +meter sign after the clef. Using the previous notation, + + \discretionary{bar meter}{clef meter}{ bar meter } + +In Lilypond, we have the same concepts (and the same +terminology). Each (nonrhythmic) symbol is typeset using a Command +(code: TYPESET). At a breakpoint, TYPESET commands can be grouped +using separators (in lower case): + + BREAK_PRE, typeset(bar), typeset(meter), + BREAK_MID, typeset(bar), typeset(meter), + BREAK_POST, typeset(clef), typeset(meter), BREAK_END + +The BREAK command sequence is terminated with BREAK_END, so other +commands (like INTERPRET) may follow this sequence. + |