Re: [Denemo-devel] Setting X-offset and Y-offset graphically.

[Richard Shann]

On Tue, 2013-04-23 at 18:23 +0200, Janek Warchoł wrote:
> 2013/4/23 Richard Shann <address@hidden>:
> > On Tue, 2013-04-23 at 17:49 +0200, Janek Warchoł wrote:
> >> What about this: ask the user to drag the control points.  Then he
> >> doesn't have to click precisely on the control point.
> >
> > ... well, continuing from my email in response to Urs
> > Denemo does not know where anything is until told. So if you click near
> > the first control point Denemo cannot draw the curve, so you get no
> > visualization of the shape...
> 
> aah.  That's a pity.
> 
> >> In more detail:
> >> - user enters slur editing mode, control points appear.
> >> - user clicks near first control point
> >> - holding the mouse button down, he moves the cursor 2 units
> >> horizontally and 1 unit vertically, then he releases the button.
> > this is the point where no newly drawn curve can be shown by Denemo
> > because it does not know where the other control points are.
> 
> Could you please insert blank lines between quoted message and your
> reply?  I've almost overlooked it.

thanks for warning me - I'll keep that in mind.

> Anyway, to me this feature would be helpful even without new curve
> preview - i've shaped so many slurs that my brain learned how to
> calculate bezier curves with quite good precision :)
> But a preview would obviously be very helpful.
> 
> Hey, i have an idea: what about conbining both approaches?
> - user enters slur editing mode, control points appear.
> - user clicks on first control point
> - holding the mouse button down, he moves the cursor 2 units
> horizontally and 1 unit vertically, then he releases the button -
> Denemo uses this release position as an approximation of resulting
> control point position (i.e. where the control point will be after
> \shape moves it)

That is, Denemo would store two numbers for x and y distances moved
while dragging

> - this becomes \shape #'((2 . 1) ... )
> - similarly for other control points.
> - with all control points done, "new shape preview" would be displayed
> using information from all "release points".

yes, by storing the drop points of each drag.

> - user can further tweak the curve by dragging points around.

yes

> 
> looks brilliant! ;)

It is good for those who know what is going on - quite difficult to
introduce to someone with no understanding of control points.

Thank you for all the thought you have put in,

Richard