diff options
| -rw-r--r-- | cc/picture_pile_impl.cc | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/cc/picture_pile_impl.cc b/cc/picture_pile_impl.cc index cb4ff2b..8475f49 100644 --- a/cc/picture_pile_impl.cc +++ b/cc/picture_pile_impl.cc @@ -59,13 +59,15 @@ void PicturePileImpl::Raster( base::TimeTicks rasterizeBeginTime = base::TimeTicks::Now(); - // TODO(enne): do this more efficiently, i.e. top down with Skia clips canvas->save(); canvas->translate(-content_rect.x(), -content_rect.y()); canvas->clipRect(gfx::RectToSkRect(content_rect)); - for (PicturePile::Pile::const_iterator i = pile_.begin(); - i != pile_.end(); ++i) { + // Raster through the pile top down, using clips to make sure that + // pictures on top are not overdrawn by pictures on the bottom. + Region unclipped(content_rect); + for (PicturePile::Pile::reverse_iterator i = pile_.rbegin(); + i != pile_.rend(); ++i) { // This is intentionally *enclosed* rect, so that the clip is aligned on // integral post-scale content pixels and does not extend past the edges of // the picture's layer rect. The min_contents_scale enforces that enough @@ -73,13 +75,16 @@ void PicturePileImpl::Raster( // invalidated pixels at any larger scale level. gfx::Rect content_clip = gfx::ToEnclosedRect( gfx::ScaleRect((*i)->LayerRect(), contents_scale)); - if (!content_rect.Intersects(content_clip)) + if (!unclipped.Intersects(content_clip)) continue; - (*i)->Raster(canvas, content_clip, contents_scale); - SkISize deviceSize = canvas->getDeviceSize(); - stats->totalPixelsRasterized += deviceSize.width() * deviceSize.height(); + // Don't allow pictures underneath to draw where this picture did. + canvas->clipRect(gfx::RectToSkRect(content_clip), SkRegion::kDifference_Op); + unclipped.Subtract(content_clip); + + stats->totalPixelsRasterized += + content_clip.width() * content_clip.height(); } canvas->restore(); |