cc: Replace recorded region with direct map lookup

cc/resources/picture_pile.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/picture_pile.h"
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 146 matching lines @@
     RenderingStatsInstrumentation* stats_instrumentation) {
   background_color_ = background_color;
   contents_opaque_ = contents_opaque;
 
   gfx::Rect interest_rect = visible_layer_rect;
   interest_rect.Inset(
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord);
+  recorded_viewport_ = interest_rect;
+  recorded_viewport_.Intersect(gfx::Rect(size()));
 
   bool invalidated = false;
   for (Region::Iterator i(invalidation); i.has_rect(); i.next()) {
     gfx::Rect invalidation = i.rect();
     // Split this inflated invalidation across tile boundaries and apply it
     // to all tiles that it touches.
-    for (TilingData::Iterator iter(&tiling_, invalidation);
-         iter; ++iter) {
+    bool include_borders = true;
+    for (TilingData::Iterator iter(&tiling_, invalidation, include_borders);
+         iter;
+         ++iter) {
       const PictureMapKey& key = iter.index();
 
       PictureMap::iterator picture_it = picture_map_.find(key);
       if (picture_it == picture_map_.end())
         continue;
 
       // Inform the grid cell that it has been invalidated in this frame.
       invalidated = picture_it->second.Invalidate(frame_number) || invalidated;
     }
   }
 
   // Make a list of all invalid tiles; we will attempt to
   // cluster these into multiple invalidation regions.
   std::vector<gfx::Rect> invalid_tiles;
-
-  for (TilingData::Iterator it(&tiling_, interest_rect);
-       it; ++it) {
+  bool include_borders = true;
+  for (TilingData::Iterator it(&tiling_, interest_rect, include_borders); it;
+       ++it) {
     const PictureMapKey& key = it.index();
     PictureInfo& info = picture_map_[key];
 
     gfx::Rect rect = PaddedRect(key);
     int distance_to_visible =
         rect.ManhattanInternalDistance(visible_layer_rect);
 
     if (info.NeedsRecording(frame_number, distance_to_visible)) {
       gfx::Rect tile = tiling_.TileBounds(key.first, key.second);
       invalid_tiles.push_back(tile);
+    } else if (recorded_viewport_.Intersects(rect)) {

[vmpstr, 2014/03/18 17:24:54]

Should this have a "&& !info.picture"? If it doesn't need recording, because it
has a picture, then it's correctly in the recorded viewport, no?

[enne (OOO), 2014/03/18 17:52:16]

Oh! Yes!

+      // Recorded viewport is just an optimization for a fully recorded
+      // interest rect.  In this case, a tile in that rect has declined
+      // to be recorded (probably due to frequent invalidations).
+      // TODO(enne): Shrink the recorded_viewport_ rather than clearing.
+      recorded_viewport_ = gfx::Rect();

[enne (OOO), 2014/03/18 00:55:20]

The core issue is that if something gets invalidated offscreen, then this cached
recorded viewport rect that is filled with valid tiles is no longer true.  So,
this needs to be cleared here.

     }
   }
 
   std::vector<gfx::Rect> record_rects;
   ClusterTiles(invalid_tiles, &record_rects);
 
-  if (record_rects.empty()) {
-    if (invalidated)
-      UpdateRecordedRegion();
+  if (record_rects.empty())
     return invalidated;
-  }
 
   for (std::vector<gfx::Rect>::iterator it = record_rects.begin();
        it != record_rects.end();
        it++) {
     gfx::Rect record_rect = *it;
     record_rect = PadRect(record_rect);
 
     int repeat_count = std::max(1, slow_down_raster_scale_factor_for_debug_);
     scoped_refptr<Picture> picture;
     int num_raster_threads = RasterWorkerPool::GetNumRasterThreads();
@@ skipping 15 matching lines @@
                                   num_raster_threads);
         base::TimeDelta duration =
             stats_instrumentation->EndRecording(start_time);
         best_duration = std::min(duration, best_duration);
       }
       int recorded_pixel_count =
           picture->LayerRect().width() * picture->LayerRect().height();
       stats_instrumentation->AddRecord(best_duration, recorded_pixel_count);
     }
 
-    for (TilingData::Iterator it(&tiling_, record_rect);
-        it; ++it) {
+    bool found_tile_for_recorded_picture = false;
+
+    bool include_borders = true;
+    for (TilingData::Iterator it(&tiling_, record_rect, include_borders); it;
+         ++it) {
       const PictureMapKey& key = it.index();
       gfx::Rect tile = PaddedRect(key);
       if (record_rect.Contains(tile)) {
         PictureInfo& info = picture_map_[key];
         info.SetPicture(picture);
+        found_tile_for_recorded_picture = true;
       }
     }
+    DCHECK(found_tile_for_recorded_picture);
   }
 
-  UpdateRecordedRegion();
+  has_any_recordings_ = true;
+  DCHECK(CanRasterSlowTileCheck(recorded_viewport_));

[enne (OOO), 2014/03/18 00:55:20]

Just an additional sanity check.

   return true;
 }
 
 }  // namespace cc