kwin: Optimize WindowQuadList::makeGrid()

This is the same optimization that was done in makeRegularGrid()
in 45782d387ab894c682b4ccc220e596c8b72c4167.
This commit is contained in:
Fredrik Höglund 2013-09-09 17:28:46 +02:00
parent 006529d8b2
commit 76adeb6a13

View file

@ -997,41 +997,54 @@ WindowQuadList WindowQuadList::splitAtY(double y) const
return ret;
}
WindowQuadList WindowQuadList::makeGrid(int maxquadsize) const
WindowQuadList WindowQuadList::makeGrid(int maxQuadSize) const
{
if (empty())
return *this;
// find the bounding rectangle
double left = first().left();
double right = first().right();
double top = first().top();
// Find the bounding rectangle
double left = first().left();
double right = first().right();
double top = first().top();
double bottom = first().bottom();
foreach (const WindowQuad & quad, *this) {
foreach (const WindowQuad &quad, *this) {
#ifndef NDEBUG
if (quad.isTransformed())
kFatal(1212) << "Splitting quads is allowed only in pre-paint calls!" ;
#endif
left = qMin(left, quad.left());
right = qMax(right, quad.right());
top = qMin(top, quad.top());
left = qMin(left, quad.left());
right = qMax(right, quad.right());
top = qMin(top, quad.top());
bottom = qMax(bottom, quad.bottom());
}
WindowQuadList ret;
for (double x = left;
x < right;
x += maxquadsize) {
for (double y = top;
y < bottom;
y += maxquadsize) {
foreach (const WindowQuad & quad, *this) {
if (QRectF(QPointF(quad.left(), quad.top()), QPointF(quad.right(), quad.bottom()))
.intersects(QRectF(x, y, maxquadsize, maxquadsize))) {
ret.append(quad.makeSubQuad(qMax(x, quad.left()), qMax(y, quad.top()),
qMin(quad.right(), x + maxquadsize), qMin(quad.bottom(), y + maxquadsize)));
}
foreach (const WindowQuad &quad, *this) {
const double quadLeft = quad.left();
const double quadRight = quad.right();
const double quadTop = quad.top();
const double quadBottom = quad.bottom();
// Compute the top-left corner of the first intersecting grid cell
const double xBegin = left + qFloor((quadLeft - left) / maxQuadSize) * maxQuadSize;
const double yBegin = top + qFloor((quadTop - top) / maxQuadSize) * maxQuadSize;
// Loop over all intersecting cells and add sub-quads
for (double y = yBegin; y < quadBottom; y += maxQuadSize) {
const double y0 = qMax(y, quadTop);
const double y1 = qMin(quadBottom, y + maxQuadSize);
for (double x = xBegin; x < quadRight; x += maxQuadSize) {
const double x0 = qMax(x, quadLeft);
const double x1 = qMin(quadRight, x + maxQuadSize);
ret.append(quad.makeSubQuad(x0, y0, x1, y1));
}
}
}
return ret;
}