[PD-dev] remove tk scaling

[Hans-Christoph Steiner]

In general, removing bits of code willy-nilly is a bad idea.  In this case, it
took a ton of testing to get the right set of tweaks working across all
platforms smoothly with the same pixel sizes on all platforms.  Given that you
only tested on GNU/Linux, its a really bad idea to propose changes based only
on one platform unless you are planning to drop support for all other platforms.

So follow what the comment there says: "This guarantees that patches will be
pixel-exact on every platform".  If we had a pure Tcl/Tk GUI, then we could
actually use tk scaling, and allow the user to adjust the tk scaling number,
thereby having a zoomable interface.  That will require removing all GUI logic
from the pd core and putting it only in the GUI.

.hc

On 06/12/2013 07:54 PM, Miller Puckette wrote:
> Hi Jonathan et a -
> 
> I've never understood the reason tk_scaling is touched in the TK code and
> unless someone else objects I'll try taking it out of the vanilla source.
> 
> thanks
> Miller
> 
> On Tue, Jun 11, 2013 at 06:11:57PM -0700, Jonathan Wilkes wrote:
>> Hi list,
>>
>> From tcl/pd-gui:
>>     # we are not using Tk scaling, so fix it to 1 on all platforms.  This
>>     # guarantees that patches will be pixel-exact on every platform
>>     tk scaling 1
>>
>> From #tcl on freenode:
>> <jancsika> hello. does tk scaling affect canvas items?
>> <ijchain> <emiliano> jancsika: no
>>
>> From my own experiments on Debian:
>> * setting the tk scaling to 1, 0.2, 3, or 200 does not alter
>> a canvas text item, either for positive (pointsize) font sizes
>> or negative (pixelsize) font sizes
>> * with version 8.5.11, setting tk scaling to 1, 0.2, 3, or 200
>> _will_ change the actual number of pixels a canvas requests
>> from its parent _if_ you pack it without any option flags.
>> (e.g., scaling at 0.2 will request a tiny rectangle and scaling
>> at 200 will be bigger than the visible screen area, at least on
>> my laptop).  However, Pd packs its canvas items to fill the
>> cavity provided by the toplevel parent (which always has
>> its geometry set explicitly), so no matter what tk scaling value
>> you set the canvas will be exactly the right size.
>>
>> You can check this by setting tk scaling to any value at all.
>> The tk widgets will of course look different (that's what tk
>> scaling affects, after all), but just click <ctrl-n> for a new
>> patch and it will look exactly right.  Also try:
>>
>> [label foo(
>> |
>> [vsl]
>>
>> ... and you will find that even iemguis have _exactly_ the
>> same font size no matter what you provided for tk scaling.
>>
>> Effect of [tk scaling 1] command:
>> causes tiny fonts in various widgets on Windows, which then
>> requires a dev to fire up Pd on a Windows machine and
>> screw around with the options database until they find the
>> correct string to set the menufont
>>
>> Side effect: if you want to embed tk widgets in a patch, not
>> having tk scaling frozen at "1" may end up making those widgets
>> have different sizes on different platforms.  But even with
>> [tk scaling 1] you cannot guarantee pixel-exactness in this case,
>> because tk uses native widgets from the OS, and different OSes
>> will request different padding, font-sizes, images, etc. for those
>> widgets.
>>
>> So-- is there any reason not to remove "tk scaling 1"?
>>
>> Thanks,
>> Jonathan
> 
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