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Re: Painter and viewports [message #43965 is a reply to message #43964]

Mon, 01 December 2014 22:03

mdelfede
Messages: 1307
Registered: September 2007

Ultimate Contributor

Hi Didier,

thank you for answer.

I use Painter because I need to work in floating point units, scale and so on,
and I don't want to replicate all that stuff Wink

Btw, I use a big painting area because I just do drawing regens when I modify it,
then I "move" the viewport over it to pan/zoom, so I spare some graphic calculations.

I found a solution, anyways.
Now I've got the problem of transparency.

I need to paint 2 transparent drawings over a background, i.e.:

	// create an imagebuffer to paint inside
	ImageBuffer ib(sz);
	
	// place it on requested viewport
	BufferPainter bp(ib);
	bp.Scale(scale, scale);
	bp.Translate(-x1 - WORK_AREA / 2, -y1 + WORK_AREA / 2);
	
	// paint work area
	INTERLOCKED_(doc->RegenMutex()) {
		One<PaintingPainter> &workArea = doc->GetWorkArea();
		if(!workArea.IsEmpty())
			bp.Paint(*workArea);
	}

	// paint overlayer
	bp.Paint(*doc->GetOverlayArea());
	
	// display it
	w.DrawImage(0, 0, ib);

workArea and overlayArea are both cleared with RGBAZero() color.
But when I paint on bp object (which has a white background...) I get garbage.
If I clear the painters with a color, all is ok, but I loose the overlay stuff.

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