Command split crescendoText ?

[Xavier Scheuer]

Hi,

I'd like to create a command that will create a textual crescendo split 
into three parts : cre - - - scen - - - do, with the following properties :
 - aligned on dynamic-line (well, like \crescTextCresc) ;
 - with the "scen" part in the middle (X-axis speaking) of "cre" and 
"do" (that should be the most difficult I think).

I'd like to use a syntax like

  a8\startCresc a a a a8 a a a |
  a8 a a a a8\endCresc a a a |

where result would be looking like (that's what I'm doing for now) :

  \set crescendoText = \markup { \italic "cre" }
  \set crescendoSpanner = #'text
  a8\< a a a a8 a
  \textSpannerDown
  \override TextSpanner #'(bound-details left stencil-align-dir-y) = #0
  \override TextSpanner #'(bound-details right stencil-align-dir-y) = #0
  \override TextSpanner #'(bound-details left text) = \markup { \large 
\italic "scen" }
  \override TextSpanner #'(bound-details right text) = \markup { \large 
\italic "do" }
  a\!\startTextSpan a |
  a8 a a a a8\stopTextSpan a a a8 |

Could somebody "imagine" for me such a command by "Tweaking with 
Scheme", I'm afraid I couldn't for now ?

Many thanks in advance,


Xavier