QWMatrix::mapRect

[Pharell]

Hello all,

I am fighting with a problem regarding mapping a rectangle which is not of

QRect type. I want to rotate the rectangle 90 degree counterclockwise and

I just did it as follow but the result is not what I want.Instead the rectangle

gets larger in size. Can someone give me suggestions how to solve this problem?

QWMatrix matrixWorld;
	 QRect newRect;
	 double rotateDegree = 90.0;
 
	 newRect.setRect(myRect.Left(), myRect.Top(), myRect.Width(), myRect.Height()); 
	 matrixWorld.rotate(rotateDegree);
	 newRect =  matrixWorld.mapRect(newRect);
	 myRect.Rect(newRect.left(), newRect.top(), newRect.width(), newRect.height());

QWMatrix matrixWorld;
	 QRect newRect;
	 double rotateDegree = 90.0;

	 newRect.setRect(myRect.Left(), myRect.Top(), myRect.Width(), myRect.Height()); 
	 matrixWorld.rotate(rotateDegree);
	 newRect =  matrixWorld.mapRect(newRect);
	 myRect.Rect(newRect.left(), newRect.top(), newRect.width(), newRect.height());

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[aamer4yu]

What is QWMatrix ???

[Pharell]

The QWMatrix class specifies 2D transformations of a coordinate system.
The standard coordinate system of a paint device has the origin located at the top-left position. X values increase to the right; Y values increase downward.

[Pharell]

Anyone knows how to solve this problem??

[spirit]

in Qt I found only QMatrix and there are some small examples with rotation. the interafe of this class very similar to class which you was describe.

[jacek]

You can do the 90 degrees rotation without any matrices. Just swap coordinates and multiply one of them by -1.