cc: 9patch: fix shadow scaling issue

cc/layers/nine_patch_layer_impl.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/layers/nine_patch_layer_impl.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "cc/base/math_util.h"
 #include "cc/quads/solid_color_draw_quad.h"
@@ skipping 59 matching lines @@
 
   image_aperture_ = aperture;
   border_ = border;
   fill_center_ = fill_center;
   nearest_neighbor_ = nearest_neighbor;
   layer_occlusion_ = layer_occlusion;
 
   NoteLayerPropertyChanged();
 }
 
+bool NinePatchLayerImpl::CanUseOcclusion() {
+  if (layer_occlusion_.IsEmpty())
+    return false;
+
+  if (fill_center_)
+    return false;
+
+  if (border_.x() == 0 || border_.y() == 0 ||

[aelias_OOO_until_Jul13, 2016/05/05 04:17:57]

All this state is known to the client-side code in ui/ so can you move this
logic there and leave NinePatchLayerImpl simply checking
(layer_occlusion_.IsEmpty())?  This will make NinePatchLayerImpl's behavior more
predictable (in the sense that it will never silently drop the occlusion, which
would regress performance in a hard-to-notice way).

[llandwerlin-old, 2016/05/06 16:26:48]

Done.

+      (border_.width() - border_.x()) == 0 ||
+      (border_.height() - border_.y()) == 0)
+    return false;
+
+  if (layer_occlusion_.x() == 0 || layer_occlusion_.y() == 0 ||
+      layer_occlusion_.right() == bounds().width() ||
+      layer_occlusion_.bottom() == bounds().height())
+    return false;
+
+  return true;
+}
+
 void NinePatchLayerImpl::CheckGeometryLimitations() {
   // |border| is in layer space.  It cannot exceed the bounds of the layer.
   DCHECK_GE(bounds().width(), border_.width());
   DCHECK_GE(bounds().height(), border_.height());
 
   // Sanity Check on |border|
   DCHECK_LE(border_.x(), border_.width());
   DCHECK_LE(border_.y(), border_.height());
   DCHECK_GE(border_.x(), 0);
   DCHECK_GE(border_.y(), 0);
@@ skipping 81 matching lines @@
 
   return patches;
 }
 
 std::vector<NinePatchLayerImpl::Patch>
 NinePatchLayerImpl::ComputeQuadsWithOcclusion() const {
   float image_width = image_bounds_.width();
   float image_height = image_bounds_.height();
   int layer_width = bounds().width();
   int layer_height = bounds().height();
-  gfx::Rect image_occlusion(
-      BoundsToRect(layer_occlusion_.x(), layer_occlusion_.y(),
-                   image_width - (layer_width - layer_occlusion_.right()),
-                   image_height - (layer_height - layer_occlusion_.bottom())));
-  gfx::Rect layer_aperture(
-      BoundsToRect(image_aperture_.x(), image_aperture_.y(),
-                   layer_width - (image_width - image_aperture_.right()),
-                   layer_height - (image_height - image_aperture_.bottom())));
+  int layer_border_right = border_.width() - border_.x();
+  int layer_border_bottom = border_.height() - border_.y();
+  int image_aperture_right = image_width - image_aperture_.right();
+  int image_aperture_bottom = image_height - image_aperture_.bottom();
+  int layer_occlusion_right = layer_width - layer_occlusion_.right();
+  int layer_occlusion_bottom = layer_height - layer_occlusion_.bottom();
+  gfx::Rect image_occlusion(BoundsToRect(
+      layer_occlusion_.x() * image_aperture_.x() / border_.x(),
+      layer_occlusion_.y() * image_aperture_.y() / border_.y(),
+      image_width -
+          layer_occlusion_right * image_aperture_right / layer_border_right,
+      image_height -
+          layer_occlusion_bottom * image_aperture_bottom /
+              layer_border_bottom));
+  gfx::Rect layer_aperture(border_.x(), border_.y(),
+                           layer_width - border_.width(),
+                           layer_height - border_.height());
 
   std::vector<Patch> patches;
   patches.reserve(kMaxOcclusionPatches);
 
   // Top-left-left.
   patches.push_back(
       Patch(BoundsToRect(0, 0, image_occlusion.x(), image_aperture_.y()),
             BoundsToRect(0, 0, layer_occlusion_.x(), layer_aperture.y())));
 
   // Top-left-right.
@@ skipping 91 matching lines @@
   ResourceId resource =
       layer_tree_impl()->ResourceIdForUIResource(ui_resource_id_);
 
   if (!resource)
     return;
 
   DCHECK(!bounds().IsEmpty());
 
   std::vector<Patch> patches;
 
-  if (!layer_occlusion_.IsEmpty() && border_.IsEmpty() && !fill_center_)
+  if (CanUseOcclusion())
     patches = ComputeQuadsWithOcclusion();
   else
     patches = ComputeQuadsWithoutOcclusion();
 
   const float vertex_opacity[] = {1.0f, 1.0f, 1.0f, 1.0f};
   const bool opaque = layer_tree_impl()->IsUIResourceOpaque(ui_resource_id_);
   static const bool flipped = false;
   static const bool premultiplied_alpha = true;
 
   for (const auto& patch : patches) {
@@ skipping 43 matching lines @@
   list->AppendInteger(layer_occlusion_.x());
   list->AppendInteger(layer_occlusion_.y());
   list->AppendInteger(layer_occlusion_.width());
   list->AppendInteger(layer_occlusion_.height());
   result->Set("LayerOcclusion", list);
 
   return result;
 }
 
 }  // namespace cc