From 854c9519c4d2aef9a2541c7a1684340b6c75d0f4 Mon Sep 17 00:00:00 2001 From: James Lowe Date: Sun, 7 Aug 2011 11:45:53 +0100 Subject: [PATCH] Doc: NR 5.5.4 - Modifying ties and slurs Started off as adding a @cindex for 'control points'. Ended up tidying up the overall description of how the bezier curve describes its arc. Then noted a reference to a non-existant property of the TieColumn object - so I have referred to the correct interface for this property and added an @seealso. --- .../notation/changing-defaults.itely | 69 ++++++++++--------- 1 file changed, 36 insertions(+), 33 deletions(-) diff --git a/Documentation/notation/changing-defaults.itely b/Documentation/notation/changing-defaults.itely index 7f1bb0f0a0..14847f8c16 100644 --- a/Documentation/notation/changing-defaults.itely +++ b/Documentation/notation/changing-defaults.itely @@ -3622,33 +3622,35 @@ Notation Reference: @cindex slurs, modifying @cindex ties, modifying -@cindex Bézier curves -@cindex Bézier control points - -Ties, slurs and phrasing slurs are drawn as third-order Bézier -curves. If the shape of the tie or slur which is calculated -automatically is not optimum, the shape may be modified manually by -explicitly specifying the four control points required to define -a third-order Bézier curve. - -Third-order or cubic Bézier curves are defined by four control -points. The first and fourth control points are precisely the -starting and ending points of the curve. The intermediate two -control points define the shape. Animations showing how the curve -is drawn can be found on the web, but the following description -may be helpful. The curve starts from the first control point -heading directly towards the second, gradually bending over to -head towards the third and continuing to bend over to head towards -the fourth, arriving there travelling directly from the third -control point. The curve is entirely contained in the -quadrilateral defined by the four control points. - -Here is an example of a case where the tie is not optimum, and -where @code{\tieDown} would not help. +@cindex Bézier curves, control points +@cindex control points, Bézier curves + +If the shape of the tie or slur which is calculated automatically is not +optimum, the shape may be modified manually by explicitly specifying the +control points required to define the curve needed. + +Ties, slurs and phrasing slurs are drawn as @q{third-order} Bézier +curves which are are defined by four control points. The first and +fourth control points are the start and end points of the curve +respectively, and the two intermediate control points define the +overall shape. + +Animations showing how the curve is drawn can be found on the web, but +the following description may be helpful. The curve starts from the +first control point moving towards the second. As the curve nears and +passes through the second control point it begins to arc towards the +third. The curve continues on towards the the third control point, +again starting to arc as it nears and passes through the third so as to +finish the curve smoothly at the fourth and final control point. The +whole curve is contained in the quadrilateral defined by the four +control points. + +Here is an example of a case where the tie is not optimum (and where the +@code{\tieDown} command would not help). @lilypond[verbatim,quote,relative=1] << - { e1 ~ e } + { e1~ e } \\ { r4 } >> @@ -3681,23 +3683,24 @@ to which the start of the tie (or slur) is attached. { \once \override Tie #'control-points = #'((1 . -1) (3 . 0.6) (12.5 . 0.6) (14.5 . -1)) - e1 ~ e1 + e1 ~ e } \\ - { r4 4 } + { r4 } >> @end lilypond @knownissues - It is not possible to modify shapes of ties or slurs by changing -the @code{control-points} property if there are more than one at -the same musical moment, not even by using the @code{\tweak} -command. However, the @code{tie-configuration} property of -@code{TieColumn} can be overridden to set start line and direction -of ties as required. - +the @code{control-points} property if there are multiple ties or slurs +at the same musical moment -- the @code{\tweak} command will also not +work in this case. However, the @code{tie-configuration} property of +@code{tie-column-interface} can be overridden to set start line and +direction of ties as required. +@seealso +Internals Reference: +@rinternals{tie-column-interface}. @node Using music functions -- 2.39.2