Re: Start, end, gradient of Glissando

[Aaron Hill]

On 2021-10-23 5:17 am, Thomas Morley wrote:
> Any hints?

normalized-endpoints

Your Y-left and Y-right are the extreme values that have not been 
interpolated using the values from normalized-endpoints.  Borrowing 
logic from Line_spanner::print, here is a modification to your test 
code:

%%%%
           (normalized-endpoints (ly:grob-property grob 
'normalized-endpoints))
           (Y-length (- Y-right Y-left))
           (normal-Y-left (+ Y-left (* (car normalized-endpoints) 
Y-length)))
           (normal-Y-right (- Y-right (* (- 1 (cdr 
normalized-endpoints)) Y-length)))
           (start-coord
             (cons
               (- X-left grob-relative-coord (- left-padding) (/ thick 
2))
               (+ normal-Y-left left-padding-y)))
           (end-coord
             (cons
               (- X-right grob-relative-coord right-padding (- (/ thick 
2)))
               (- normal-Y-right right-padding-y current-y-coord))))
%%%%


-- Aaron Hill