[Interest] QML Image sourceSize bug (?)

[Giuseppe D'Angelo]

On 27/03/2021 15:46, Alexander Dyagilev wrote:
> 
> If I enable mipmap, it looks much better comparing to original variant,
> but still worse comparing to the final one (described in my original
> posting).
> 
> I can provide you all the screenshots if you want to.

I can only entertain that mipmapping in your case is going to use 
trilinear interpolation (*) between the 32x32 and the 16x16 mip. And, 
for your particular image ("artwork" / "icon"), that is giving you worse 
results than a 27x27 image scaled directly from the source via bilinear 
interpolation.

There's not much to do about this:

* mipmapping allows you to keep a good visual quality if the displayed 
size of the image changes
* sourceSize allows you to get a good scaled-down version and save on 
memory, but will look awful if now you try to make the image bigger again

(*) didn't check the actual code, just assumed a GL_LINEAR_MIPMAP_LINEAR 
setting.


HTH,
-- 
Giuseppe D'Angelo | giuseppe.dangelo at kdab.com | Senior Software Engineer
KDAB (France) S.A.S., a KDAB Group company
Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com
KDAB - The Qt, C++ and OpenGL Experts

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