[Qt-interest] QGraphicsView and perspective

[John Clayton]

Hi All,

Two questions, the context for both is:
	- Qt 4.6.2
	- Mac 10.6.3

(1) QGraphcisView & perspective

Is there a recommended way to change the perspective value of a QGraphicsView?  I've got a single QGraphicsPixmapItem in one simple QWidget based view, and I am applying a rotation to it.  The Mac/Cocoa based version of this that is using pure opengl, looks like this:

I don't see any explicit methods to set the perspective transformation on the view itself, and when I tried to override this by setting my own derived QGLWidget that uses its own MODELVIEW and PROJECTION matrices, that had no effect either (which upon more reflection makes sense).

(2) Antialiasing with an OpenGL QGraphicsView

My QGraphicsView based pixmap appears very very pixelated, is there a way to improve this situation?  I've tried turning on all the high quality rendering options I can think of on the painter and on the view, e.g. on the graphics view:

	_ui->graphicsView->setRenderHints(QPainter::HighQualityAntialiasing | 
									  QPainter::Antialiasing |
									  QPainter::TextAntialiasing | 
									  QPainter::SmoothPixmapTransform);
and when drawing the item itself:
void GraphicsItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) {
	painter->setRenderHint(QPainter::Antialiasing, true);
	painter->setRenderHint(QPainter::HighQualityAntialiasing, true);
	painter->setRenderHint(QPainter::SmoothPixmapTransform, true);
	... // call super 

Mac/Cocoa version, anti-aliased, looking yummy:
	http://idisk.me.com/john_clayton/Public/Pictures/Skitch/FileWave/mac-opengl-version-20100509-110021.png

Qt's OpenGL based QGraphicsView version - not antialiased - thus not so yummy:
	http://idisk.me.com/john_clayton/Public/Pictures/Skitch/FileWave/mac-qt-version-20100509-110318.png

Thanks
--
John Clayton
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