cc: Partial tile update for one-copy raster.

cc/resources/picture_layer_tiling.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_layer_tiling.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <set>
@@ skipping 209 matching lines @@
         tiling_data_.TileXIndexFromSrcCoord(live_tiles_rect_.right() - 1);
     after_bottom =
         tiling_data_.TileYIndexFromSrcCoord(live_tiles_rect_.bottom() - 1);
   }
 
   // There is no recycled twin since this is run on the pending tiling
   // during commit, and on the active tree during activate.
   // Drop tiles outside the new layer bounds if the layer shrank.
   for (int i = after_right + 1; i <= before_right; ++i) {
     for (int j = before_top; j <= before_bottom; ++j)
-      RemoveTileAt(i, j);
+      RemoveTileAt(i, j, nullptr);
   }
   for (int i = before_left; i <= after_right; ++i) {
     for (int j = after_bottom + 1; j <= before_bottom; ++j)
-      RemoveTileAt(i, j);
+      RemoveTileAt(i, j, nullptr);
   }
 
   if (after_right > before_right) {
     DCHECK_EQ(after_right, before_right + 1);
     for (int j = before_top; j <= after_bottom; ++j) {
       if (ShouldCreateTileAt(after_right, j))
         CreateTile(after_right, j);
     }
   }
   if (after_bottom > before_bottom) {
@@ skipping 10 matching lines @@
                  !client_->GetPendingOrActiveTwinTiling(this));
   RemoveTilesInRegion(layer_invalidation, true /* recreate tiles */);
 }
 
 void PictureLayerTiling::RemoveTilesInRegion(const Region& layer_invalidation,
                                              bool recreate_tiles) {
   // We only invalidate the active tiling when it's orphaned: it has no pending
   // twin, so it's slated for removal in the future.
   if (live_tiles_rect_.IsEmpty())
     return;
-  std::vector<TileMapKey> new_tile_keys;
+  struct InvalidTiles {
+    TileMapKey key;
+    gfx::Rect invalid_rect;
+  };
+  std::vector<InvalidTiles> new_tile_keys;

[vmpstr, 2015/05/14 17:58:49]

If you make this a (hash)map keyed by TileMapKey, then I think the logic below
is a bit simpler... ie

gfx::Rect& inv = new_tile_keys[iter.index()];
inv.Union(content_rect);

[danakj, 2015/05/14 19:59:47]

enne@ just pointed out to me that I can just union on the Tile directly and
don't need to do extra vector walks here with temporary rects.

[vmpstr, 2015/05/14 20:08:34]

You'd still need to record which tiles were invalidated though, so I guess
you'll also keep the original vector then? Temp map of key to rect doesn't sound
too bad to me, but whatever makes the code simpler is good with me.

[danakj, 2015/05/14 20:10:18]

The original vector of keys, yah. I have this change in the last patchset, I
think it's pretty clean.

   gfx::Rect expanded_live_tiles_rect =
       tiling_data_.ExpandRectIgnoringBordersToTileBounds(live_tiles_rect_);
   for (Region::Iterator iter(layer_invalidation); iter.has_rect();
        iter.next()) {
     gfx::Rect layer_rect = iter.rect();
     gfx::Rect content_rect =
         gfx::ScaleToEnclosingRect(layer_rect, contents_scale_);
     // Consider tiles inside the live tiles rect even if only their border
     // pixels intersect the invalidation. But don't consider tiles outside
     // the live tiles rect with the same conditions, as they won't exist.
     int border_pixels = tiling_data_.border_texels();
     content_rect.Inset(-border_pixels, -border_pixels);
     // Avoid needless work by not bothering to invalidate where there aren't
     // tiles.
     content_rect.Intersect(expanded_live_tiles_rect);
     if (content_rect.IsEmpty())
       continue;
     // Since the content_rect includes border pixels already, don't include
     // borders when iterating to avoid double counting them.
     bool include_borders = false;
     for (
         TilingData::Iterator iter(&tiling_data_, content_rect, include_borders);
         iter; ++iter) {
-      if (RemoveTileAt(iter.index_x(), iter.index_y())) {
-        if (recreate_tiles)
-          new_tile_keys.push_back(iter.index());
+      auto it = std::find_if(
+          new_tile_keys.begin(), new_tile_keys.end(),
+          [&iter](const InvalidTiles& inv) { return inv.key == iter.index(); });
+      if (it == new_tile_keys.end()) {
+        InvalidTiles inv;
+        inv.key = iter.index();
+        new_tile_keys.push_back(inv);
+        it = new_tile_keys.end() - 1;
       }
+      it->invalid_rect.Union(content_rect);
     }
   }
 
-  for (const auto& key : new_tile_keys)
-    CreateTile(key.first, key.second);
+  for (const InvalidTiles& inv : new_tile_keys) {
+    Tile::Id old_id;
+    if (RemoveTileAt(inv.key.first, inv.key.second, &old_id) &&
+        recreate_tiles) {
+      Tile* tile = CreateTile(inv.key.first, inv.key.second);
+      tile->SetInvalidated(inv.invalid_rect, old_id);
+    }
+  }
 }
 
 void PictureLayerTiling::SetRasterSourceOnTiles() {
   if (tree_ == PENDING_TREE)
     return;
 
   for (TileMap::value_type& tile_pair : tiles_)
     tile_pair.second->set_raster_source(raster_source_.get());
 }
 
@@ skipping 185 matching lines @@
   texture_rect.Scale(dest_to_content_scale_,
                      dest_to_content_scale_);
   texture_rect.Intersect(gfx::Rect(tiling_->tiling_size()));
   if (texture_rect.IsEmpty())
     return texture_rect;
   texture_rect.Offset(-tex_origin.OffsetFromOrigin());
 
   return texture_rect;
 }
 
-bool PictureLayerTiling::RemoveTileAt(int i, int j) {
+bool PictureLayerTiling::RemoveTileAt(int i, int j, Tile::Id* id) {
   TileMap::iterator found = tiles_.find(TileMapKey(i, j));
   if (found == tiles_.end())
     return false;
+  if (id)
+    *id = found->second->id();
   tiles_.erase(found);
   return true;
 }
 
 void PictureLayerTiling::Reset() {
   live_tiles_rect_ = gfx::Rect();
   tiles_.clear();
 }
 
 gfx::Rect PictureLayerTiling::ComputeSkewport(
@@ skipping 137 matching lines @@
          gfx::Rect(tiling_size()).Contains(new_live_tiles_rect))
       << "tiling_size: " << tiling_size().ToString()
       << " new_live_tiles_rect: " << new_live_tiles_rect.ToString();
   if (live_tiles_rect_ == new_live_tiles_rect)
     return;
 
   // Iterate to delete all tiles outside of our new live_tiles rect.
   for (TilingData::DifferenceIterator iter(&tiling_data_, live_tiles_rect_,
                                            new_live_tiles_rect);
        iter; ++iter) {
-    RemoveTileAt(iter.index_x(), iter.index_y());
+    RemoveTileAt(iter.index_x(), iter.index_y(), nullptr);
   }
 
   // Iterate to allocate new tiles for all regions with newly exposed area.
   for (TilingData::DifferenceIterator iter(&tiling_data_, new_live_tiles_rect,
                                            live_tiles_rect_);
        iter; ++iter) {
     TileMapKey key(iter.index());
     if (ShouldCreateTileAt(key.first, key.second))
       CreateTile(key.first, key.second);
   }
@@ skipping 378 matching lines @@
       break;
   }
 
   gfx::Rect result(origin_x, origin_y, width, height);
   if (cache)
     cache->previous_result = result;
   return result;
 }
 
 }  // namespace cc