Impl Namespace Reference

Classes
struct	CheckFullyTransparent
struct	CheckNonDefault

Functions
template<class ComparePixelOp >
QRect	calculateExactBoundsImpl (const KisPaintDevice *device, const QRect &startRect, const QRect &endRect, ComparePixelOp compareOp)

Function Documentation

calculateExactBoundsImpl()

template<class ComparePixelOp >

QRect Impl::calculateExactBoundsImpl	(	const KisPaintDevice *	device,
		const QRect &	startRect,
		const QRect &	endRect,
		ComparePixelOp	compareOp )

If the first pass hasn't found any opaque pixel, there is no reason to check that 3 more times. They will not appear in the meantime. Just return an empty bounding rect.

Definition at line 1323 of file kis_paint_device.cc.

{
    if (startRect == endRect) return startRect;
 
    // the passed extent might have weird invalid structure that
    // can overflow integer precision when calling startRect.right()
    if (!startRect.isValid()) return QRect();
 
    // Solution n°2
    int  x, y, w, h;
    int boundLeft, boundTop, boundRight, boundBottom;
    int endDirN, endDirE, endDirS, endDirW;
 
    startRect.getRect(&x, &y, &w, &h);
 
    if (endRect.isEmpty()) {
        endDirS = startRect.bottom();
        endDirN = startRect.top();
        endDirE = startRect.right();
        endDirW = startRect.left();
        startRect.getCoords(&boundLeft, &boundTop, &boundRight, &boundBottom);
    } else {
        endDirS = endRect.top() - 1;
        endDirN = endRect.bottom() + 1;
        endDirE = endRect.left() - 1;
        endDirW = endRect.right() + 1;
        endRect.getCoords(&boundLeft, &boundTop, &boundRight, &boundBottom);
    }
 
    // XXX: a small optimization is possible by using H/V line iterators in the first
    //      and third cases, at the cost of making the code a bit more complex
 
    KisRandomConstAccessorSP accessor = device->createRandomConstAccessorNG();
 
    bool found = false;
    {
        for (qint32 y2 = y; y2 <= endDirS; ++y2) {
            for (qint32 x2 = x; x2 < x + w || found; ++ x2) {
                accessor->moveTo(x2, y2);
                if (!compareOp.isPixelEmpty(accessor->rawDataConst())) {
                    boundTop = y2;
                    found = true;
                    break;
                }
            }
            if (found) break;
        }
    }
 
    if (!found && endRect.isEmpty()) {
        return QRect();
    }
 
    found = false;
 
    for (qint32 y2 = y + h - 1; y2 >= endDirN ; --y2) {
        for (qint32 x2 = x + w - 1; x2 >= x || found; --x2) {
            accessor->moveTo(x2, y2);
            if (!compareOp.isPixelEmpty(accessor->rawDataConst())) {
                boundBottom = y2;
                found = true;
                break;
            }
        }
        if (found) break;
    }
    found = false;
 
    {
        for (qint32 x2 = x; x2 <= endDirE ; ++x2) {
            for (qint32 y2 = y; y2 < y + h || found; ++y2) {
                accessor->moveTo(x2, y2);
                if (!compareOp.isPixelEmpty(accessor->rawDataConst())) {
                    boundLeft = x2;
                    found = true;
                    break;
                }
            }
            if (found) break;
        }
    }
 
    found = false;
 
    // Look for right edge )
    {
 
        for (qint32 x2 = x + w - 1; x2 >= endDirW; --x2) {
            for (qint32 y2 = y + h - 1; y2 >= y || found; --y2) {
                accessor->moveTo(x2, y2);
                if (!compareOp.isPixelEmpty(accessor->rawDataConst())) {
                    boundRight = x2;
                    found = true;
                    break;
                }
            }
            if (found) break;
        }
    }
 
    return QRect(boundLeft, boundTop,
                 boundRight - boundLeft + 1,
                 boundBottom - boundTop + 1);
}

References KisPaintDevice::createRandomConstAccessorNG(), KisRandomConstAccessorNG::moveTo(), and KisBaseConstAccessor::rawDataConst().