bool
ClientTiledPaintedLayer::UseProgressiveDraw() {
if (!gfxPlatform::GetPlatform()->UseProgressivePaint()) {
// pref is disabled, so never do progressive
return false;
}
if (!mContentClient->GetTiledBuffer()->SupportsProgressiveUpdate()) {
return false;
}
if (ClientManager()->HasShadowTarget()) {
// This condition is true when we are in a reftest scenario. We don't want
// to draw progressively here because it can cause intermittent reftest
// failures because the harness won't wait for all the tiles to be drawn.
return false;
}
if (mPaintData.mCriticalDisplayPort.IsEmpty()) {
// This catches three scenarios:
// 1) This layer doesn't have a scrolling ancestor
// 2) This layer is subject to OMTA transforms
// 3) Low-precision painting is disabled
// In all of these cases, we don't want to draw this layer progressively.
return false;
}
if (GetIsFixedPosition() || GetParent()->GetIsFixedPosition()) {
// This layer is fixed-position and so even if it does have a scrolling
// ancestor it will likely be entirely on-screen all the time, so we
// should draw it all at once
return false;
}
if (ClientManager()->AsyncPanZoomEnabled()) {
LayerMetricsWrapper scrollAncestor;
GetAncestorLayers(&scrollAncestor, nullptr, nullptr);
MOZ_ASSERT(scrollAncestor); // because mPaintData.mCriticalDisplayPort is non-empty
const FrameMetrics& parentMetrics = scrollAncestor.Metrics();
if (!IsScrollingOnCompositor(parentMetrics)) {
return false;
}
}
return true;
}
bool
ClientTiledPaintedLayer::UseFastPath()
{
LayerMetricsWrapper scrollAncestor;
GetAncestorLayers(&scrollAncestor, nullptr);
if (!scrollAncestor) {
return true;
}
const FrameMetrics& parentMetrics = scrollAncestor.Metrics();
bool multipleTransactionsNeeded = gfxPlatform::GetPlatform()->UseProgressivePaint()
|| gfxPrefs::UseLowPrecisionBuffer()
|| !parentMetrics.GetCriticalDisplayPort().IsEmpty();
bool isFixed = GetIsFixedPosition() || GetParent()->GetIsFixedPosition();
bool isScrollable = parentMetrics.IsScrollable();
return !multipleTransactionsNeeded || isFixed || !isScrollable
#if !defined(MOZ_WIDGET_ANDROID) || defined(MOZ_ANDROID_APZ)
|| !IsScrollingOnCompositor(parentMetrics)
#endif
;
}
