[Qt-interest] [Qt-Interest] Visual Studio 2010 Compile of 64 bit Qt 4.7.1 Results in bad executables

[Konrad Rosenbaum]

On Tuesday 28 December 2010, Michael Jackson wrote:
> I don't want to start any type of argument, but let's pretend for a
> second that I don't actually know what each and every possible
> configuration option does and so I need to depend on the help from the
> "configure" script. So using "configure --help" I see the following:
> 
>     -graphicssystem <sys> Specify which graphicssystem should be used.
>                           Available values for <sys>:
>  *                         raster - Software rasterizer
>                            opengl - Using OpenGL acceleration,
> experimental! openvg - Using OpenVG acceleration, experimental!

With Qt: if you do not know what the option does, leave it to Qt to chose a 
good default. It usually works. If it does not then it is time to read very 
deeply into the matter.

> Now, since I am creating a program that displays very large images (10k x
> 10k pixels) i certainly don't want the "raster - Software Rasterizer".

You don't want to send images that large to your graphics system. Period.

By a quick calculation the ARGB version of that image is about 400MB big! 
Add to this shadow copies at various places in the system (application, 
graphics subsystem, driver, double buffering) and you are out of memory.

Besides: most graphics systems have a limit on coordinates - usually in the 
realm of 4096 or 8192 pixels in each direction.

In short: you'll have to do extensive preprocessing with those images, so 
that the graphics system can swallow the pieces or zooms that you actually 
want to see.


	Konrad
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part.
Url : http://lists.qt-project.org/pipermail/qt-interest-old/attachments/20101229/2592ad82/attachment.bin