[Interest] How to render small Images decently on non retina displays with QtQuick?

Uwe Rathmann Uwe.Rathmann at tigertal.de
Thu Mar 8 07:18:05 CET 2018

On Wed, 07 Mar 2018 20:55:03 +0100, Jason H wrote:

> How is QPicture not appropriate for SVG?

At the time, when Qt changed its APIs from integers to doubles ( Qt 4 ) 
QPicture::boundingRect() was forgotten, what makes layouting of scaled 
pictures too inaccurate.

Another important detail are non cosmetic pens. You need to know about 
them as they might grow outside the bounding rectangle.

Beyond that QPicture stores painter commands in a platform-independent 
format, what makes it less performant and the file sizes are larger.

In the end ( not yet implemented ) I want to mmap my precompiled SVGs 
into memory. Then, copying all precompiled SVGs at boot time into a RAM 
drive and you have almost zero overhead for IO. 


More information about the Interest mailing list