[Ipe-discuss] How to resize image to specific length

[Otfried Cheong]

Yes, this is not as easy it might be - I noticed this several times. 
The problem is that in scale mode, the scaling factor is simply
determined by the ratio by which you move the cursor (as seen from the
scaling origin), so, as you say, the corner "drags behind", unless you
move exactly on the diagonal.

I'm open for suggestions for how scale mode could be more intuitive.

Right now, what works is the following:  

With vertex snapping (F4) on, do:

Translate the top left corner of the image to its target position.  

Then, go to the *target* top right corner and draw a vertical auxiliary
line downwards from there.

Go back to the top left corner and set the coordinate system there (F1).
Go to the bottom right corner of the image and set the direction (F2). 
This will set the main coordinate direction to be the diagonal of the
image.

 Turn on boundary snapping (F5).  Use scale mode to drag the bottom
 right corner of the image to the intersection of the coordinate axis
 and the auxiliary line (since both boundary and angular snapping are
 on, the cursor will snap to this intersection point).

Cheers,
 Otfried


On Fri, Oct 7, 2016, at 18:44, Nikolaus Rath wrote:
> Hello,
> 
> I would like to re-size an image to a specific length (or height), while 
> keeping the aspect ratio preserved.
> 
> How do I do that?
> 
> My naive attempt was to grab the left upper corner of the image (using 
> control point snapping) and move it to the desired location. Then I'd 
> grab the right upper corner with the resize tool, hold shift, and move 
> it horizontally to the desired position (using grid snapping).
> 
> Unfortunately this does not work. While the cursor snaps to the current 
> position, the corner of the image actually "drags behind", so it ends up 
> larger than it should be.
> 
> Best,
> -Nikolaus
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