cc : Compute visible rects dynamically (1)

cc/trees/damage_tracker_unittest.cc

 // Copyright 2011 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/trees/damage_tracker.h"
 
 #include <stddef.h>
 
 #include "cc/base/math_util.h"
 #include "cc/layers/layer_impl.h"
@@ skipping 10 matching lines @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/effects/SkBlurImageFilter.h"
 #include "ui/gfx/geometry/quad_f.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 
 namespace cc {
 namespace {
 
 void ExecuteCalculateDrawProperties(LayerImpl* root,
                                     float device_scale_factor,
+                                    bool skip_verify_visible_rect_calculations,
                                     LayerImplList* render_surface_layer_list) {
   // Sanity check: The test itself should create the root layer's render
   //               surface, so that the surface (and its damage tracker) can
   //               persist across multiple calls to this function.
   ASSERT_FALSE(render_surface_layer_list->size());
 
   FakeLayerTreeHostImpl::RecursiveUpdateNumChildren(root);
   LayerTreeHostCommon::CalcDrawPropsImplInputsForTesting inputs(
       root, root->bounds(), device_scale_factor, render_surface_layer_list);
+  if (skip_verify_visible_rect_calculations)
+    inputs.verify_visible_rect_calculations = false;
   LayerTreeHostCommon::CalculateDrawPropertiesForTesting(&inputs);
   ASSERT_TRUE(root->render_surface());
 }
 
 void ClearDamageForAllSurfaces(LayerImpl* root) {
   for (auto* layer : *root->layer_tree_impl()) {
     if (layer->render_surface())
       layer->render_surface()->damage_tracker()->DidDrawDamagedArea();
   }
 }
 
-void EmulateDrawingOneFrame(LayerImpl* root, float device_scale_factor = 1.f) {
+void EmulateDrawingOneFrame(
+    LayerImpl* root,
+    float device_scale_factor = 1.f,
+    bool skip_verify_visible_rect_calculations = false) {
   // This emulates only steps that are relevant to testing the damage tracker:
   //   1. computing the render passes and layerlists
   //   2. updating all damage trackers in the correct order
   //   3. resetting all update_rects and property_changed flags for all layers
   //      and surfaces.
 
   LayerImplList render_surface_layer_list;
   ExecuteCalculateDrawProperties(root, device_scale_factor,
+                                 skip_verify_visible_rect_calculations,
                                  &render_surface_layer_list);
 
   // Iterate back-to-front, so that damage correctly propagates from descendant
   // surfaces to ancestors.
   size_t render_surface_layer_list_size = render_surface_layer_list.size();
   for (size_t i = 0; i < render_surface_layer_list_size; ++i) {
     size_t index = render_surface_layer_list_size - 1 - i;
     RenderSurfaceImpl* target_surface =
         render_surface_layer_list[index]->render_surface();
     target_surface->damage_tracker()->UpdateDamageTrackingState(
@@ skipping 1593 matching lines @@
 
     gfx::Transform transform;
     transform.Translate(-kBigNumber, -kBigNumber);
 
     // The child layer covers (0, 0, i, i) of the viewport,
     // but has a huge negative position.
     child->SetPosition(gfx::PointF());
     child->SetBounds(gfx::Size(kBigNumber + i, kBigNumber + i));
     child->test_properties()->transform = transform;
     root->layer_tree_impl()->property_trees()->needs_rebuild = true;
-    EmulateDrawingOneFrame(root);
+    float device_scale_factor = 1.f;
+    // Visible rects computed from combining clips in target space and root
+    // space don't match because of the loss in floating point accuracy. So, we
+    // skip verify_clip_tree_calculations.
+    bool skip_verify_visible_rect_calculations = true;
+    EmulateDrawingOneFrame(root, device_scale_factor,
+                           skip_verify_visible_rect_calculations);
 
     // The expected damage should cover the visible part of the child layer,
     // which is (0, 0, i, i) in the viewport.
     gfx::Rect root_damage_rect =
         root->render_surface()->damage_tracker()->current_damage_rect();
     gfx::Rect damage_we_care_about = gfx::Rect(i, i);
     EXPECT_LE(damage_we_care_about.right(), root_damage_rect.right());
     EXPECT_LE(damage_we_care_about.bottom(), root_damage_rect.bottom());
   }
 }
 
 }  // namespace
 }  // namespace cc