Further plumb visual rect into cc:DisplayItemList.

ui/compositor/clip_transform_recorder.cc

 // Copyright 2015 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 "ui/compositor/clip_transform_recorder.h"
 
 #include "base/logging.h"
 #include "cc/playback/clip_display_item.h"
 #include "cc/playback/clip_path_display_item.h"
 #include "cc/playback/display_item_list.h"
 #include "cc/playback/transform_display_item.h"
 #include "ui/compositor/paint_context.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/path.h"
 
 namespace ui {
 
-ClipTransformRecorder::ClipTransformRecorder(const PaintContext& context)
-    : context_(context), num_closers_(0) {
-}
+ClipTransformRecorder::ClipTransformRecorder(const PaintContext& context,
+                                             const gfx::Size& layer_size)

[danakj, 2015/11/17 22:14:33]

IIRC when we'd talked about this, we discussed "layer_size" being a bit
ambiguous, and "size_in_layer" being more obvious. i'd prefer that throughout as
the outcome.

[wkorman, 2015/11/17 23:43:04]

Done.

+    : context_(context),
+      layer_bounds_(context.ToLayerSpaceBounds(layer_size)),
+      num_closers_(0) {}
 
 ClipTransformRecorder::~ClipTransformRecorder() {
   for (size_t i = 0; i < num_closers_; ++i) {
     switch (closers_[i]) {
       case CLIP_RECT:
-        context_.list_->CreateAndAppendItem<cc::EndClipDisplayItem>();
+        context_.list_->CreateAndAppendItem<cc::EndClipDisplayItem>(
+            layer_bounds_);
         break;
       case CLIP_PATH:
-        context_.list_->CreateAndAppendItem<cc::EndClipPathDisplayItem>();
+        context_.list_->CreateAndAppendItem<cc::EndClipPathDisplayItem>(
+            layer_bounds_);
         break;
       case TRANSFORM:
-        context_.list_->CreateAndAppendItem<cc::EndTransformDisplayItem>();
+        context_.list_->CreateAndAppendItem<cc::EndTransformDisplayItem>(
+            layer_bounds_);
         break;
     }
   }
 }
 
 void ClipTransformRecorder::ClipRect(const gfx::Rect& clip_rect) {
-  auto* item = context_.list_->CreateAndAppendItem<cc::ClipDisplayItem>();
+  gfx::Rect clip_in_layer_space = clip_rect + context_.offset_;

[danakj, 2015/11/17 22:14:33]

also i'd prefer adding a PaintContext method to convert the rect instead of
using offset_ directly here, but a helper method above

[danakj, 2015/11/17 22:14:33]

similar to this (with or without _space, but maybe consistently?)

[wkorman, 2015/11/17 23:43:05]

Added and made use of PaintContext::ToLayerSpaceRect(). That method name is sort
of ambiguous since as implemented/described in the comment it does one specific
thing, but one could imagine lots of ways one might want to convert a rect to be
a rect in layer space. Anyway, it's documented, and we can iterate as we learn
more.

+  auto* item = context_.list_->CreateAndAppendItem<cc::ClipDisplayItem>(
+      clip_in_layer_space);
   item->SetNew(clip_rect, std::vector<SkRRect>());
   DCHECK_LT(num_closers_, arraysize(closers_));
   closers_[num_closers_++] = CLIP_RECT;
 }
 
 void ClipTransformRecorder::ClipPath(const gfx::Path& clip_path) {
   bool anti_alias = false;
-  auto* item = context_.list_->CreateAndAppendItem<cc::ClipPathDisplayItem>();
+  // As a further optimization, consider passing a more granular visual rect.
+  auto* item = context_.list_->CreateAndAppendItem<cc::ClipPathDisplayItem>(
+      layer_bounds_);
   item->SetNew(clip_path, SkRegion::kIntersect_Op, anti_alias);
   DCHECK_LT(num_closers_, arraysize(closers_));
   closers_[num_closers_++] = CLIP_PATH;
 }
 
 void ClipTransformRecorder::ClipPathWithAntiAliasing(
     const gfx::Path& clip_path) {
   bool anti_alias = true;
-  auto* item = context_.list_->CreateAndAppendItem<cc::ClipPathDisplayItem>();
+  // As a further optimization, consider passing a more granular visual rect.
+  auto* item = context_.list_->CreateAndAppendItem<cc::ClipPathDisplayItem>(
+      layer_bounds_);
   item->SetNew(clip_path, SkRegion::kIntersect_Op, anti_alias);
   DCHECK_LT(num_closers_, arraysize(closers_));
   closers_[num_closers_++] = CLIP_PATH;
 }
 
 void ClipTransformRecorder::Transform(const gfx::Transform& transform) {
-  auto* item = context_.list_->CreateAndAppendItem<cc::TransformDisplayItem>();
+  auto* item = context_.list_->CreateAndAppendItem<cc::TransformDisplayItem>(
+      layer_bounds_);
   item->SetNew(transform);
   DCHECK_LT(num_closers_, arraysize(closers_));
   closers_[num_closers_++] = TRANSFORM;
 }
 
 }  // namespace ui