Bug 749063 - Prioritise visible tiles when progressively updating. r=bgirard

When progressively updating tiles, prioritise tiles that intersect with the
current viewport before off-screen tiles. New content is still prioritised
over stale content.
This commit is contained in:
Chris Lord 2012-10-15 09:33:48 +01:00
parent bc223170e4
commit fec9404d96

View File

@ -250,10 +250,11 @@ BasicTiledThebesLayer::PaintThebes(gfxContext* aContext,
mValidRegion = nsIntRegion();
}
nsIntRegion regionToPaint = mVisibleRegion;
regionToPaint.Sub(regionToPaint, mValidRegion);
if (regionToPaint.IsEmpty())
nsIntRegion invalidRegion = mVisibleRegion;
invalidRegion.Sub(invalidRegion, mValidRegion);
if (invalidRegion.IsEmpty())
return;
nsIntRegion regionToPaint = invalidRegion;
gfxSize resolution(1, 1);
for (ContainerLayer* parent = GetParent(); parent; parent = parent->GetParent()) {
@ -277,23 +278,55 @@ BasicTiledThebesLayer::PaintThebes(gfxContext* aContext,
if (gfxPlatform::UseProgressiveTilePainting() &&
mTiledBuffer.GetResolution() == resolution &&
(scrollDiffX != 0 || scrollDiffY != 0)) {
// Paint tiles that have no content before tiles that only have stale content.
nsIntRegion staleRegion = mTiledBuffer.GetValidRegion();
staleRegion.And(staleRegion, regionToPaint);
bool hasNewContent = !staleRegion.Contains(regionToPaint);
if (!staleRegion.IsEmpty() && hasNewContent) {
regionToPaint.Sub(regionToPaint, staleRegion);
}
// Find out if we have any non-stale content to update.
nsIntRegion freshRegion = mTiledBuffer.GetValidRegion();
freshRegion.And(freshRegion, invalidRegion);
freshRegion.Sub(invalidRegion, freshRegion);
// Find out the current view transform to determine which tiles to draw
// first, and see if we should just abort this paint. Aborting is usually
// caused by there being an incoming, more relevant paint.
gfx::Rect viewport;
float scaleX, scaleY;
if (BasicManager()->ProgressiveUpdateCallback(hasNewContent, viewport, scaleX, scaleY)) {
if (BasicManager()->ProgressiveUpdateCallback(!freshRegion.IsEmpty(), viewport, scaleX, scaleY)) {
return;
}
// Prioritise tiles that are currently visible on the screen.
// Get the transform to the current layer.
gfx3DMatrix transform = GetEffectiveTransform();
// XXX Not sure if this code for intermediate surfaces is correct.
// It rarely gets hit though, and shouldn't have terrible consequences
// even if it is wrong.
for (ContainerLayer* parent = GetParent(); parent; parent = parent->GetParent()) {
if (parent->UseIntermediateSurface()) {
transform.PreMultiply(parent->GetEffectiveTransform());
}
}
transform.Invert();
// Transform the screen coordinates into local layer coordinates.
gfxRect transformedViewport(viewport.x - (scrollOffset.x * resolution.width),
viewport.y - (scrollOffset.y * resolution.height),
viewport.width, viewport.height);
transformedViewport.Scale((scaleX / resolution.width) / resolution.width,
(scaleY / resolution.height) / resolution.height);
transformedViewport = transform.TransformBounds(transformedViewport);
nsIntRect roundedTransformedViewport((int32_t)floor(transformedViewport.x),
(int32_t)floor(transformedViewport.y),
(int32_t)ceil(transformedViewport.width),
(int32_t)ceil(transformedViewport.height));
// Paint tiles that have no content before tiles that only have stale content.
if (!freshRegion.IsEmpty()) {
regionToPaint = freshRegion;
}
if (regionToPaint.Intersects(roundedTransformedViewport)) {
regionToPaint.And(regionToPaint, roundedTransformedViewport);
}
// The following code decides what order to draw tiles in, based on the
// current scroll direction of the primary scrollable layer.
// XXX While this code is of a reasonable size currently, it is likely
@ -337,10 +370,12 @@ BasicTiledThebesLayer::PaintThebes(gfxContext* aContext,
nsIntRect(paintTileStartX, paintTileStartY,
mTiledBuffer.GetTileLength(), mTiledBuffer.GetTileLength()));
if (!maxPaint.Contains(regionToPaint)) {
// Expand the paint region to tile boundaries
regionToPaint.And(invalidRegion, maxPaint);
if (!regionToPaint.Contains(invalidRegion)) {
// The region needed to paint is larger then our progressive chunk size
// therefore update what we want to paint and ask for a new paint transaction.
regionToPaint.And(regionToPaint, maxPaint);
BasicManager()->SetRepeatTransaction();
// Make sure that tiles that fall outside of the visible region are discarded.