Re: Art backend Was: Package building

[Fred Kiefer]

HI Sergii,

> Am 03.12.2019 um 14:39 schrieb Sergii Stoian <stoyan255@gmail.com>:
> On Sun, Nov 24, 2019 at 11:34 AM Fred Kiefer <fredkiefer@gmx.de> wrote:
> > Am 23.11.2019 um 23:33 schrieb Sergii Stoian <stoyan255@gmail.com>:
> > 
> >> I havent tried in the last weeks/months, but the last release worked. Of 
> >> course, it has all specific "issues" of art which where never solved. But 
> >> it is faster for certain operations and curves and anti-aliasing are 
> >> exquisite. Using Graphos on art is a delight.
> >> 
> > What do you mean by “worked”? I observed incomplete words in menus and 
> > popup buttons. Incorrect alignment of items in popup buttons - I suppose 
> > it’s due to incorrect lengthOfString results. Also I suppose I’ve found 
> > cause of a problem - NSStringDrawing caching methods rewrite by Fred. But I 
> > can’t understand what changes must be applied to ART backend to adopt new 
> > caching algorithm.
> 
> I am willing to help here if you could pinpoint the issue a bit down. Which 
> commit are you talking about and in which situations does it show? The last 
> time I used the art backend I did not see any issues. But I must confess I 
> only checked with Ink.
> 
> I've made some screenshots with 0.27 version of GUI and Back (please see 
> attachments) to illustrate some inconsistencies.
> FontPreferencesPopUp and LocalizationPreferences-* illustrate NSPopUpButton 
> text drawing.
> WorkspaceMenu+HelpPanel illustrates - i guess - related problem: "Workspace" 
> menu lacks border at the right side. 
> The other problem is with my custom HelpPanel that contains NSMatrix with 
> index list (note selection offset).
> Plus (it's hard to make screenshot of insertion point) in NXTHelpPanel's 
> NSTextField insertion point drawn shifted at 20-30 pixels to the right until 
> there's no entered text.
> 
> Now I'm using 0.25 version of GUI and Back - all works correcly. 
> Somewhere between 0.25 and 0.25.1 of GUI NSStringDrawing was massively 
> changed by you. Do you know what is the cause of these inconsistencies?

With the recent mail flood on the GNUstep mailing lists I require some more 
background to be sure we talk about the same thing here.

The screenshots you made were for the art backend?
Could you please explain in more detail what is wrong with each specific screen 
shot? I can see that some entries in the popup list are shortened. What else is 
wrong?
The GNUstep guy release 0.25.0 was in June 2016 and the following 0.25.1 
release almost a year later. There have been plenty of relevant changes in the 
string drawing during that time. The most important probably was to usage of 
cached glyph advancements, but also the change in the string drawing cache 
handling you mention. Could you try to pin down the commit that broke things 
for you?

The art backend is no longer actively maintained. I understand that you and 
Riccardo still prefer it. Here it would help if you could provide patches to 
get it working again. I am not very familiar with the art text handling code.
If you want to debug the popup button issue you should start off with the 
NSMenuItemCell drawing methods, here drawTitleXXX is the most likely starting 
point.

Cheers,
Fred