Rotation on Qframe

[Pharell]

Hello,

I am using QT3 and am not so much fimiliar with the qt-programming. I have to make a rotation function on a qframe widget. I have my own rectangle class. The follow is what i have made but its not done correctly. Can someone please take a look at the code and give me some suggestion?

double View::Rotate(double a_dRotate)
{
	MyRect m_Dev;
	MyRect m_Form;
	FRect m_Window;
 
	int iWidth = m_Dev.Width();
 
	QRect R = rect();
	m_Form.Rect( R.left(), R.top(), R.right(), R.bottom() );
 
	m_Dev.Width(m_Dev.Width() * a_dRotate);
 
	if (m_Dev.Width() > 12000)
		m_Dev.Width(12000);
 
	if (m_Dev.Width() > 5000000)
		m_Dev.Width(5000000);
 
	if (m_Dev.Width() < 50)
		m_Dev.Width(50);
 
 
m_Dev.Height( (double)m_Dev.Width() / ((double)m_Window.Width() / (double)m_Window.Height()) );
return ((double)m_Dev.Width() / (double)iWidth);
}

double View::Rotate(double a_dRotate)
{
	MyRect m_Dev;
	MyRect m_Form;
	FRect m_Window;
	
	int iWidth = m_Dev.Width();

	QRect R = rect();
	m_Form.Rect( R.left(), R.top(), R.right(), R.bottom() );

	m_Dev.Width(m_Dev.Width() * a_dRotate);

	if (m_Dev.Width() > 12000)
		m_Dev.Width(12000);

	if (m_Dev.Width() > 5000000)
		m_Dev.Width(5000000);
	
	if (m_Dev.Width() < 50)
		m_Dev.Width(50);


m_Dev.Height( (double)m_Dev.Width() / ((double)m_Window.Width() / (double)m_Window.Height()) );
return ((double)m_Dev.Width() / (double)iWidth);
}

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[wysota]

What exactly are you trying to rotate? Have you seen QWMatrix::rotate()?

[Pharell]

What exactly are you trying to rotate? Have you seen QWorldMatrix::rotate()?

A rectangle inside a qframe. I have seen QWorldMatrix but can i use it with QRECT?

[wysota]

Take a look at QWMatrix::mapRect().

[Pharell]

Take a look at QWMatrix::mapRect().

I have changed my code as follows but it doesnt work at all.

MyRect m_Dev;
       MyRect m_Form;
       QRect View = rect();
       QWMatrix m;                   
 
	int x = -( m_Dev.Left() - ((View.left() + View.right()) ) );
	int y = -( m_Dev.Top()  - ((View.top()  + View.bottom()) ) );
	m.mapRect(View); 
	m.rotate( -45.0 );

MyRect m_Dev;
       MyRect m_Form;
       QRect View = rect();
       QWMatrix m;                   

	int x = -( m_Dev.Left() - ((View.left() + View.right()) ) );
	int y = -( m_Dev.Top()  - ((View.top()  + View.bottom()) ) );
	m.mapRect(View); 
	m.rotate( -45.0 );

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[wysota]

Because it doesn't work that way.

QWMatrix m;
m.rotate(-45);
QRect newRect = m.mapRect(rect());

QWMatrix m;
m.rotate(-45);
QRect newRect = m.mapRect(rect());

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Look closely what each method does and returns.

[Pharell]

Because it doesn't work that way.

QWMatrix m;
m.rotate(-45);
QRect newRect = m.mapRect(rect());

QWMatrix m;
m.rotate(-45);
QRect newRect = m.mapRect(rect());

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Look closely what each method does and returns.

Yep thnx alot. But i see stil some mis calculation in my methods i have one main class which has these two functions and it is XView: QFrame -

double XView::Rotate(double a_dRotate)
{
	QWMatrix m;
	m.rotate(22);
        QRect newRect = m.mapRect(rect()); 
	return a_dRotate; 
}
 
void XView::Rotate(double a_dRotate, double x, double y)
{
	double rotateView = Rotate(a_dRotate);
 
	x *= rotateView;
	y *= rotateView;
}

double XView::Rotate(double a_dRotate)
{
	QWMatrix m;
	m.rotate(22);
        QRect newRect = m.mapRect(rect()); 
	return a_dRotate; 
}

void XView::Rotate(double a_dRotate, double x, double y)
{
	double rotateView = Rotate(a_dRotate);

	x *= rotateView;
	y *= rotateView;
}

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In my other class which is View: XView, i have a slot which should do the rotation and it is as follows:

void View::SlotRotate()
{
 
	QRect View = rect();               
 
        //in this place the rectangle is calculated,
	int x = -( m_Dev.Left() - ((View.left() + View.right()) ) );
	int y = -( m_Dev.Top()  - ((View.top()  + View.bottom()) ) );
 
 
	Rotate(22, x, y); 
}

void View::SlotRotate()
{

	QRect View = rect();               

        //in this place the rectangle is calculated,
	int x = -( m_Dev.Left() - ((View.left() + View.right()) ) );
	int y = -( m_Dev.Top()  - ((View.top()  + View.bottom()) ) );
    
	
	Rotate(22, x, y); 
}

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I see that its not working properly.

[wysota]

double XView::Rotate(double a_dRotate)
{
	QWMatrix m;
	m.rotate(22);
        QRect newRect = m.mapRect(rect()); 
	return a_dRotate; 
}

double XView::Rotate(double a_dRotate)
{
	QWMatrix m;
	m.rotate(22);
        QRect newRect = m.mapRect(rect()); 
	return a_dRotate; 
}

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This code does exactly nothing. You calculate a rectangle based on some other rectangle and return the argument the method was given as a parameter. If you pass it 4.0573 it will return 4.0573, etc.


In my other class which is View: XView, i have a slot which should do the rotation and it is as follows:

void View::SlotRotate()
{
 
	QRect View = rect();               
 
        //in this place the rectangle is calculated,
	int x = -( m_Dev.Left() - ((View.left() + View.right()) ) );
	int y = -( m_Dev.Top()  - ((View.top()  + View.bottom()) ) );
 
 
	Rotate(22, x, y); 
}

void View::SlotRotate()
{

	QRect View = rect();               

        //in this place the rectangle is calculated,
	int x = -( m_Dev.Left() - ((View.left() + View.right()) ) );
	int y = -( m_Dev.Top()  - ((View.top()  + View.bottom()) ) );
    
	
	Rotate(22, x, y); 
}

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I see that its not working properly.

What would you like the code to do? Because currently your Rotate() function is meaningless, it's a no-op. SlotRotate() is also meaningless - you create a bunch of variables which you never use.

[Pharell]

Hello ppls,
I am still fighting with this rotation problem. When i debug i see that the coordinates are changing but the view is not changing. The qrect has normal (x1= 0, y1=0, x2 = 511, y2 = 469) after setting the rotate(180.0), these coordinates changes to = (x1= -511, y1 = -469, x2=0, y2= 0)

QWMatrix m;
	QRect R;
	m_Form.Rect( R.left(), R.top(), R.right(), R.bottom() );
	m.rotate(180.0);
    R =  m.mapRect(rect());

QWMatrix m;
	QRect R;
	m_Form.Rect( R.left(), R.top(), R.right(), R.bottom() );
	m.rotate(180.0);
    R =  m.mapRect(rect());

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[wysota]

What do you do with "R" afterwards?

[Pharell]

What do you do with "R" afterwards?

notting (i am really confused with it) i have send u the code of zoom yesterday and that code works fine that way. I call this function(Above code) with a slot.