QPicture Clip

[whitefurrows]

Hi,

i try to clip a QPicture:

QPicture pic; 
	QPicture target; 
 
	pic.load("c:/pic.png"); 
 
	if ( !pic.isNull ( ) ) 
	{ 
		QRect cut ( 0, pic.height()-250 ,250,250); 
		QPainter painter ( &target ); 
		painter.setClipRect(cut); 
		painter.drawPicture(0, 0, pic); 
		painter.end(); 
	} 
 
	target.save("c:/picClip.png");

QPicture pic; 
	QPicture target; 

	pic.load("c:/pic.png"); 

	if ( !pic.isNull ( ) ) 
	{ 
		QRect cut ( 0, pic.height()-250 ,250,250); 
		QPainter painter ( &target ); 
		painter.setClipRect(cut); 
		painter.drawPicture(0, 0, pic); 
		painter.end(); 
	} 

	target.save("c:/picClip.png");

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This Code don't work, why?

Thank's in advance

Whitefurrows

[jacek]

This Code don't work, why?

What exactly doesn't work? And shouldn't you use QPixmap instead of QPicture?

[whitefurrows]

Hi,

i have many problems with clip a picture and i don’t know why. This Code is a simple Example to clip a Picture. What i try to do ist hat:

void Report::printButton_clicked( const QString& html  ) 
{
QTextDocument doc;
QAbstractTextDocumentLayout::PaintContext ctx;
 
float w=533; // page width
float h=754; // page height
 
doc.setHtml(html);
// Set the TextDocument's page size
doc.setPageSize( QSizeF(w, h) );
//int pageCount=doc.pageCount();
QAbstractTextDocumentLayout *docLayout = doc.documentLayout();
 
QPainter p;
//for ( int page=1; page<=pageCount; page++){
 
	QPicture pic;
	p.begin(&pic); // Start painting
    //QRectF view(0, (page - 1) * h, w, h);
	//ctx.clip = view;
 
	// page1 and page2 only for test, i wont use the loop
	//Page1
	ctx.clip = QRectF(0,0,w,h); // Set the context clip to the first page
 
	layout->draw(&p,ctx);
 
	//Page2
	//ctx.clip = QRectF(0,h,w,h); // Set the context clip to the second page
	//docLayout->draw(&p,ctx);
 
	p.end(); // End painting
 
	//picList.append(pic);
//}
}

void Report::printButton_clicked( const QString& html  ) 
{
QTextDocument doc;
QAbstractTextDocumentLayout::PaintContext ctx;

float w=533; // page width
float h=754; // page height

doc.setHtml(html);
// Set the TextDocument's page size
doc.setPageSize( QSizeF(w, h) );
//int pageCount=doc.pageCount();
QAbstractTextDocumentLayout *docLayout = doc.documentLayout();

QPainter p;
//for ( int page=1; page<=pageCount; page++){

	QPicture pic;
	p.begin(&pic); // Start painting
    //QRectF view(0, (page - 1) * h, w, h);
	//ctx.clip = view;

	// page1 and page2 only for test, i wont use the loop
	//Page1
	ctx.clip = QRectF(0,0,w,h); // Set the context clip to the first page

	layout->draw(&p,ctx);

	//Page2
	//ctx.clip = QRectF(0,h,w,h); // Set the context clip to the second page
	//docLayout->draw(&p,ctx);

	p.end(); // End painting

	//picList.append(pic);
//}
}

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The picture won't clip. Picture1 is OK but picture2 ist picture1 + picture2 and picture3 is picture1 + picture2 + picture3..... I think that is a QT-Bug (v4.1.0) or you know what is wrong?

Greetings

Whitefurrows

[whitefurrows]

I'm very sad, i have try a lot of hour to get it work. Please give me somebody a response. I'm greatful for everything!

Thanks in advance

[jacek]

I've made a little test (see attachment) and it seems that QPainter::translate() is a key to success.

[whitefurrows]

You are my hero! That's great, the code work perfect. It's unbelievable how easy to do. A lot of thanks to you for that splendid help.

Best regards,

Whitefurrows