Harp glissandi

[Rachel Knight]

I can’t get the glissandi to look right in this passage. I followed the 
instructions for when the glissando does not end on a note. The problem is that 
the glissando is too steeply slanted downward. Rather than ending half way 
between the two quarter notes, it should end beneath the following quarter note.
Rachel



Treble = \relative c' { 
  \clef treble
  \time 4/4
  \numericTimeSignature
  \override Glissando.style = #'zigzag
        
        \scaleDurations 1/2 {
                s2
  c'4 \glissando
  \hideNotes c,,4 \unHideNotes

  c''4 \glissando
  \hideNotes c,,4 \unHideNotes

  c''4 \glissando
  \hideNotes c,,4 \unHideNotes
        }
        
  \bar "|."
        
}



Bass = \relative c' {
  \clef bass
        \numericTimeSignature
        \time 4/4

        c4 r2. |
        f,4 r2. |
        c'4 r2. |
        s1 |
        c4 s2. |
        f,4 s2. |
        g4 s2. |
        f4 s2. |
}


        \score 
                  {
                  \new GrandStaff
                  <<
                         \new Staff { \Treble } 
                        \new Staff { \Bass } 
                  >>
                }