[etoys-dev] Customizable project resolution?

[Bert Freudenberg]

On 29.12.2010, at 02:44, Xin Wang wrote:

> On Tue, Dec 28, 2010 at 11:27 PM, Bert Freudenberg <bert at freudenbergs.de> wrote:
>> 
>> On 28.12.2010, at 15:32, Xin Wang wrote:
>> 
>>> On Tue, Dec 28, 2010 at 8:31 PM, Bert Freudenberg <bert at freudenbergs.de> wrote:
>>>> 
>>>> On 28.12.2010, at 13:24, Xin Wang wrote:
>>>> 
>>>>> Hi all,
>>>>> 
>>>>> In order to share projects easily, project resolution is set to
>>>>> 1200x900, and use VirtualScreen to scale to fit the physical screen.
>>>>> 
>>>>> But for some small screens, 1200x900 is a bit large, so the project
>>>>> world has to be zoomed out a lot.  In some languages, such as Chinese,
>>>>> there are a number of font glyphs are complex, as those characters
>>>>> also has to be zoomed out, they may not be showed very clearly.
>>>>> 
>>>>> So is it better to make project resolution customizable? Just like we
>>>>> can set canvas size to any value in image manipulation programs. As
>>>>> projects are displayed using VirtualScreen, this change will not
>>>>> affect project sharing.
>>>>> 
>>>>> The bounds of project world is initialized in
>>>>> worldPasteUpMorph>>initForProject, when I change it to some other
>>>>> value instead of Display boundingBox, project displays properly, so I
>>>>> think it may be not very difficult to implement this.
>>>>> 
>>>>> So could this feature be added into Etoys?
>>>> 
>>>> You could add it to the "display mode" menu (defined in #chooseScreenSetting).
>>> 
>>> Well, I'll try to do it.
>>> 
>>>> 
>>>> Though a better solution might be to use larger fonts? On the OLPC XO we do not use screen scaling but its native 1200x900 resolution. Scaling is too slow on that laptop.
>>>> 
>>> 
>>> As font is rendered before scaling, characters seem a bit ugly after
>>> world is zoomed out.
>>> 
>>> And recently I tried to use RomePlugin in Windows, text looks alien if
>>> project is scaled, although Pango use Windows native font rendering
>>> API.
>>> 
>>> How about choose Display Actual Pixels instead of Scale To Fit in OLPC
>>> XO?
>> 
>> On XO we use "no scaling". Can't remember what happens when loading a project of different size.
>> 
>>> It does not scale the world, but just put the world in the center
>>> of screen. Does it also has a performance loss?
>> 
>> It does a double-copy, so yes, it has performance loss.
>> 
>> - Bert -
>> 
> 
> Does "double-copy" means that Etoys firstly draw on an internal buffer
> and then copy it to virtual screen?

Yes. See class OLPCVirtualScreen.

> As there is no scaling operation in "display actual pixels" mode,
> could this behavior be changed so that we can draw on virtual screen
> directly?

That should be possible, yes. Incidentally a similar question came up on another list yesterday:

http://lists.squeakfoundation.org/pipermail/beginners/2010-December/007457.html

- Bert -