[sksg] Refine invalidation logic

We need to discriminate between nodes whose bounds updates contribute to the dirty
region, and nodes whose bounds changes do not.

E.g. animated shape in a group: the animated shape node bounds should yield damage,
but the ancestor group bounds should not.

To accomplish this, we refine the invalidation state:

  1) self invalidation == the node itself was invalidated, and its bounds updates
     yield damage.
  2) descendant invalidation == the node has some (self-)invalidated descendant,
     but its own bounds are not contributing damage.

Also:

  * hoist the bounding box invalidation logic into the base class (Node::revalidate)
    and update to respect the states described above.
  * remove (now-redundant) GeometryNode bbox logic.
  * update revalidation methods to return the node bbox instead of void

TBR=
Change-Id: I8023d1793fb501c945a53f2dc2d2983e5b620ade
Reviewed-on: https://skia-review.googlesource.com/90581
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

1 files changed, 4 insertions, 9 deletions

diff --git a/experimental/sksg/SkSGDraw.cpp b/experimental/sksg/SkSGDraw.cpp
index fe6d42a152..c8e621856a 100644
--- a/experimental/sksg/SkSGDraw.cpp
+++ b/experimental/sksg/SkSGDraw.cpp
@@ -29,19 +29,14 @@ void Draw::onRender(SkCanvas* canvas) const {
     fGeometry->draw(canvas, fPaint->makePaint());
 }
 
-void Draw::onRevalidate(InvalidationController* ic, const SkMatrix& ctm) {
-    SkASSERT(this->isInvalidated());
+SkRect Draw::onRevalidate(InvalidationController* ic, const SkMatrix& ctm) {
+    SkASSERT(this->hasInval());
 
     // TODO: paint bounds extents
-    const auto oldBounds = fGeometry->fBounds;
-
-    fGeometry->revalidate(ic, ctm);
+    const auto bounds = fGeometry->revalidate(ic, ctm);
     fPaint->revalidate(ic, ctm);
 
-    ic->inval(oldBounds, ctm);
-    if (fGeometry->fBounds != oldBounds) {
-        ic->inval(fGeometry->fBounds, ctm);
-    }
+    return bounds;
 }
 
 } // namespace sksg