Proportional scaling

[Simon Lord]

Uber Danka.  :)


On Sep 21, 2004, at 1:52 PM, Wilhelm Sanke wrote:

> On Mon, 20 Sep 2004, Simon Lord wrote:
>
>> I have an object on my card which can be scaled at runtime, the next 
>> step is to get this object to scale proportionally using it's current 
>> H x W as the aspect ratio when the shiftKey is down.
>>
>> So if the object is currently shaped like a rectangle, when I hold 
>> the shiftKey down and continue dragging the object will maintain the 
>> same aspect ratio at the time I held the shiftKey down.
>>
>> Unfortunately I'm at a lose at to where to even start the math on 
>> this.
>>
>>
>> Sincerely,
>> Simon
>
>
>
> Hello Simon,
>
> The following may not match exactly your expectations, but is maybe a 
> starting point.
>
> I have a "zoom" script on card "slideshow" of my stack "Slideshow 
> Light", 82 KB (formerly to be found in Rev's User Contributions, now 
> on my website <http://www.sanke.org>, English version, page "Sample 
> Stacks").
>
> From the short description:
> "Slideshow allowing JPG-, GIF-, PNG- and BMP-images. Preview and 
> re-ordering possible. Different display sizes can be set. Zoom 
> function; adjusting of display duration during show."
>
> This zoom function does not change the images continuously, but sets 
> the new size - with the correct aspect ratio - after the dragging of 
> the scrollbar thumb has finished. I also had a continuously changing 
> version of such a zoom, but for some reason did not implement it in 
> this slideshow stack.
>
>  Examples from the scripts
>
> to put the aspect ratio into Var "Proportion":
>
>   "set the numberformat to 0.00
>   put the formattedheight of image 1 into FHoehe
>   put the formattedwidth of image 1 into FBreite
>   put FBreite / FHoehe into Proportion"
>
> script of the zoom scrollbar (assumes there are two extra scrollbars - 
> that become visible when needed - to navigate inside the enlarged 
> image):
>
> "global Proportion, Stelle
> local Neuhoehe, Neubreite
> on scrollbardrag x
>   put x into Neuhoehe
>   put Neuhoehe * Proportion into NeuBreite
>   put trunc(Neubreite) into Neubreite
>   put NeuBreite&&"X"&&Neuhoehe into fld "Rechteck"
> end scrollbardrag
>
> on mouseup
>   set the cursor to watch
>   lock screen
>   set the height of image 1 to Neuhoehe
>   set the width of image 1 to NeuBreite
>   set the loc of  image 1 to 512,384
>   if NeuBreite > 1024 then
>     put (Neubreite - 1024) div 2 into BreitDiff
>     set the Startvalue of scrollbar "horizontal" to -Breitdiff
>     set the Endvalue of scrollbar "horizontal" to Breitdiff
>     show scrollbar "Horizontal"
>   else
>     hide scrollbar "horizontal"
>   end if
>   if Neuhoehe > 768 then
>     put (Neuhoehe - 768) div 2 into HoehDiff
>     set the Startvalue of scrollbar "vertical" to -Hoehdiff
>     set the Endvalue of scrollbar "vertical" to Hoehdiff
>     show scrollbar "vertical"
>   else
>     hide scrollbar "vertical"
>   end if
>   set the thumbpos of scrollbar "vertical" to 0
>   set the thumbpos of scrollbar "horizontal" to 0
>   put the 512,384 into Stelle
>   set the cursor to hand
> end mouseup"
>
> Maybe this helps, if not - discard it.
>
> Regards,
>
> Wilhelm Sanke
> http://www.sanke.org
>
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>
>
Sincerely,
Simon