static void CalculatePluginClip(const LayoutDeviceIntRect& aBounds,
const nsTArray<LayoutDeviceIntRect>& aPluginClipRects,
const LayoutDeviceIntPoint& aContentOffset,
const LayoutDeviceIntRegion& aParentLayerVisibleRegion,
nsTArray<LayoutDeviceIntRect>& aResult,
LayoutDeviceIntRect& aVisibleBounds,
bool& aPluginIsVisible)
{
aPluginIsVisible = true;
LayoutDeviceIntRegion contentVisibleRegion;
// aPluginClipRects (plugin widget origin) - contains *visible* rects
for (uint32_t idx = 0; idx < aPluginClipRects.Length(); idx++) {
LayoutDeviceIntRect rect = aPluginClipRects[idx];
// shift to content origin
rect.MoveBy(aBounds.x, aBounds.y);
// accumulate visible rects
contentVisibleRegion.OrWith(rect);
}
// apply layers clip (window origin)
LayoutDeviceIntRegion region = aParentLayerVisibleRegion;
region.MoveBy(-aContentOffset.x, -aContentOffset.y);
contentVisibleRegion.AndWith(region);
if (contentVisibleRegion.IsEmpty()) {
aPluginIsVisible = false;
return;
}
// shift to plugin widget origin
contentVisibleRegion.MoveBy(-aBounds.x, -aBounds.y);
LayoutDeviceIntRegion::RectIterator iter(contentVisibleRegion);
for (const LayoutDeviceIntRect* rgnRect = iter.Next(); rgnRect; rgnRect = iter.Next()) {
aResult.AppendElement(*rgnRect);
aVisibleBounds.UnionRect(aVisibleBounds, *rgnRect);
}
}
