cc: Make occlusion a draw property.

cc/trees/layer_tree_host_impl.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/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 50 matching lines @@
 #include "cc/resources/software_rasterizer.h"
 #include "cc/resources/texture_mailbox_deleter.h"
 #include "cc/resources/tile_task_worker_pool.h"
 #include "cc/resources/ui_resource_bitmap.h"
 #include "cc/resources/zero_copy_tile_task_worker_pool.h"
 #include "cc/scheduler/delay_based_time_source.h"
 #include "cc/trees/damage_tracker.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_host_common.h"
 #include "cc/trees/layer_tree_impl.h"
-#include "cc/trees/occlusion_tracker.h"
 #include "cc/trees/single_thread_proxy.h"
 #include "cc/trees/tree_synchronizer.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/geometry/vector2d_conversions.h"
 
 namespace cc {
@@ skipping 503 matching lines @@
                   !output_surface_->capabilities().deferred_gl_initialization)
         << output_surface_->capabilities().delegated_rendering << " "
         << output_surface_->capabilities().deferred_gl_initialization;
     return DRAW_MODE_SOFTWARE;
   }
 }
 
 static void AppendQuadsForLayer(
     RenderPass* target_render_pass,
     LayerImpl* layer,
-    const OcclusionTracker<LayerImpl>& occlusion_tracker,
     AppendQuadsData* append_quads_data) {
-  layer->AppendQuads(
-      target_render_pass,
-      occlusion_tracker.GetCurrentOcclusionForLayer(layer->draw_transform()),
-      append_quads_data);
+  layer->AppendQuads(target_render_pass,
+                     layer->draw_properties().occlusion_in_content_space,
+                     append_quads_data);
 }
 
 static void AppendQuadsForRenderSurfaceLayer(
     RenderPass* target_render_pass,
     LayerImpl* layer,
     const RenderPass* contributing_render_pass,
-    const OcclusionTracker<LayerImpl>& occlusion_tracker,
     AppendQuadsData* append_quads_data) {
   RenderSurfaceImpl* surface = layer->render_surface();
   const gfx::Transform& draw_transform = surface->draw_transform();
-  const Occlusion& occlusion =
-      occlusion_tracker.GetCurrentOcclusionForContributingSurface(
-          draw_transform);
+  const Occlusion& occlusion = surface->occlusion_in_content_space();
   SkColor debug_border_color = surface->GetDebugBorderColor();
   float debug_border_width = surface->GetDebugBorderWidth();
   LayerImpl* mask_layer = layer->mask_layer();
 
   surface->AppendQuads(target_render_pass, draw_transform, occlusion,
                        debug_border_color, debug_border_width, mask_layer,
                        append_quads_data, contributing_render_pass->id);
 
   // Add replica after the surface so that it appears below the surface.
   if (layer->has_replica()) {
     const gfx::Transform& replica_draw_transform =
         surface->replica_draw_transform();
     const Occlusion& replica_occlusion =
-        occlusion_tracker.GetCurrentOcclusionForContributingSurface(
-            replica_draw_transform);
+        surface->replica_occlusion_in_content_space();
     SkColor replica_debug_border_color = surface->GetReplicaDebugBorderColor();
     float replica_debug_border_width = surface->GetReplicaDebugBorderWidth();
     // TODO(danakj): By using the same RenderSurfaceImpl for both the
     // content and its reflection, it's currently not possible to apply a
     // separate mask to the reflection layer or correctly handle opacity in
     // reflections (opacity must be applied after drawing both the layer and its
     // reflection). The solution is to introduce yet another RenderSurfaceImpl
     // to draw the layer and its reflection in. For now we only apply a separate
     // reflection mask if the contents don't have a mask of their own.
     LayerImpl* replica_mask_layer =
         mask_layer ? mask_layer : layer->replica_layer()->mask_layer();
 
     surface->AppendQuads(target_render_pass, replica_draw_transform,
                          replica_occlusion, replica_debug_border_color,
                          replica_debug_border_width, replica_mask_layer,
                          append_quads_data, contributing_render_pass->id);
   }
 }
 
-static void AppendQuadsToFillScreen(
-    const gfx::Rect& root_scroll_layer_rect,
-    RenderPass* target_render_pass,
-    LayerImpl* root_layer,
-    SkColor screen_background_color,
-    const OcclusionTracker<LayerImpl>& occlusion_tracker) {
+static void AppendQuadsToFillScreen(const gfx::Rect& root_scroll_layer_rect,
+                                    RenderPass* target_render_pass,
+                                    LayerImpl* root_layer,
+                                    SkColor screen_background_color,
+                                    const Region& fill_region) {
   if (!root_layer || !SkColorGetA(screen_background_color))
     return;
-
-  Region fill_region = occlusion_tracker.ComputeVisibleRegionInScreen();
   if (fill_region.IsEmpty())
     return;
 
   // Manually create the quad state for the gutter quads, as the root layer
   // doesn't have any bounds and so can't generate this itself.
   // TODO(danakj): Make the gutter quads generated by the solid color layer
   // (make it smarter about generating quads to fill unoccluded areas).
 
   gfx::Rect root_target_rect = root_layer->render_surface()->content_rect();
   float opacity = 1.f;
@@ skipping 83 matching lines @@
   // entire root surface. This will disable partial-swap/scissor optimizations
   // that would prevent the HUD from updating, since the HUD does not cause
   // damage itself, to prevent it from messing with damage visualizations. Since
   // damage visualizations are done off the LayerImpls and RenderSurfaceImpls,
   // changing the RenderPass does not affect them.
   if (active_tree_->hud_layer()) {
     RenderPass* root_pass = frame->render_passes.back();
     root_pass->damage_rect = root_pass->output_rect;
   }
 
-  OcclusionTracker<LayerImpl> occlusion_tracker(
-      active_tree_->root_layer()->render_surface()->content_rect());
-  occlusion_tracker.set_minimum_tracking_size(
-      settings_.minimum_occlusion_tracking_size);
-
-  // Add quads to the Render passes in front-to-back order to allow for testing
-  // occlusion and performing culling during the tree walk.
-  typedef LayerIterator<LayerImpl> LayerIteratorType;
+  // Grab this region here before iterating layers. Taking copy requests from

[vmpstr, 2015/02/13 00:24:54]

Do you mean to say that UnoccludedScreenSpaceRegion might change it's value
during the iteration? If so and that's not acceptable, then in this case you
probably want a copy not a const ref.

If you do want the const ref and you expect that the value of it will change,
then I might be misunderstanding the comment.

[danakj, 2015/02/13 00:27:07]

No, i mean that the dirty bit is set to true so asking for it DCHECKs. I'll
clarify.

+  // the layers while constructing the render passes will dirty the render
+  // surface layer list and this unoccluded region.
+  const Region& unoccluded_screen_space_region =
+      active_tree_->UnoccludedScreenSpaceRegion();
 
   // Typically when we are missing a texture and use a checkerboard quad, we
   // still draw the frame. However when the layer being checkerboarded is moving
   // due to an impl-animation, we drop the frame to avoid flashing due to the
   // texture suddenly appearing in the future.
   DrawResult draw_result = DRAW_SUCCESS;
   // When we have a copy request for a layer, we need to draw no matter
   // what, as the layer may disappear after this frame.
   bool have_copy_request = false;
 
   int layers_drawn = 0;
 
   const DrawMode draw_mode = GetDrawMode();
 
   int num_missing_tiles = 0;
   int num_incomplete_tiles = 0;
 
-  LayerIteratorType end =
-      LayerIteratorType::End(frame->render_surface_layer_list);
-  for (LayerIteratorType it =
-           LayerIteratorType::Begin(frame->render_surface_layer_list);
-       it != end;
-       ++it) {
+  auto end = LayerIterator<LayerImpl>::End(frame->render_surface_layer_list);
+  for (auto it =
+           LayerIterator<LayerImpl>::Begin(frame->render_surface_layer_list);
+       it != end; ++it) {
     RenderPassId target_render_pass_id =
         it.target_render_surface_layer()->render_surface()->GetRenderPassId();
     RenderPass* target_render_pass =
         frame->render_passes_by_id[target_render_pass_id];
 
-    occlusion_tracker.EnterLayer(it);
-
     AppendQuadsData append_quads_data;
 
     if (it.represents_target_render_surface()) {
       if (it->HasCopyRequest()) {
         have_copy_request = true;
         it->TakeCopyRequestsAndTransformToTarget(
             &target_render_pass->copy_requests);
       }
     } else if (it.represents_contributing_render_surface() &&
                it->render_surface()->contributes_to_drawn_surface()) {
       RenderPassId contributing_render_pass_id =
           it->render_surface()->GetRenderPassId();
       RenderPass* contributing_render_pass =
           frame->render_passes_by_id[contributing_render_pass_id];
       AppendQuadsForRenderSurfaceLayer(target_render_pass,
                                        *it,
                                        contributing_render_pass,
-                                       occlusion_tracker,
                                        &append_quads_data);
     } else if (it.represents_itself() &&
                !it->visible_content_rect().IsEmpty()) {
       bool occluded =
-          occlusion_tracker.GetCurrentOcclusionForLayer(it->draw_transform())
-              .IsOccluded(it->visible_content_rect());
+          it->draw_properties().occlusion_in_content_space.IsOccluded(
+              it->visible_content_rect());
       if (!occluded && it->WillDraw(draw_mode, resource_provider_.get())) {
         DCHECK_EQ(active_tree_, it->layer_tree_impl());
 
         frame->will_draw_layers.push_back(*it);
 
         if (it->HasContributingDelegatedRenderPasses()) {
           RenderPassId contributing_render_pass_id =
               it->FirstContributingRenderPassId();
           while (frame->render_passes_by_id.find(contributing_render_pass_id) !=
                  frame->render_passes_by_id.end()) {
             RenderPass* render_pass =
                 frame->render_passes_by_id[contributing_render_pass_id];
 
             AppendQuadsForLayer(render_pass,
                                 *it,
-                                occlusion_tracker,
                                 &append_quads_data);
 
             contributing_render_pass_id =
                 it->NextContributingRenderPassId(contributing_render_pass_id);
           }
         }
 
         AppendQuadsForLayer(target_render_pass,
                             *it,
-                            occlusion_tracker,
                             &append_quads_data);
 
         // For layers that represent themselves, add composite frame timing
         // requests if the visible rect intersects the requested rect.
         for (const auto& request : it->frame_timing_requests()) {
           const gfx::Rect& request_content_rect =
               it->LayerRectToContentRect(request.rect());
           if (request_content_rect.Intersects(it->visible_content_rect())) {
             frame->composite_events.push_back(
                 FrameTimingTracker::FrameAndRectIds(
@@ skipping 19 matching lines @@
           it->draw_transform_is_animating();
       if (layer_has_animating_transform)
         draw_result = DRAW_ABORTED_CHECKERBOARD_ANIMATIONS;
     }
 
     if (append_quads_data.num_incomplete_tiles ||
         append_quads_data.num_missing_tiles) {
       if (RequiresHighResToDraw())
         draw_result = DRAW_ABORTED_MISSING_HIGH_RES_CONTENT;
     }
-
-    occlusion_tracker.LeaveLayer(it);
   }
 
   if (have_copy_request ||
       output_surface_->capabilities().draw_and_swap_full_viewport_every_frame)
     draw_result = DRAW_SUCCESS;
 
 #if DCHECK_IS_ON()
   for (const auto& render_pass : frame->render_passes) {
     for (const auto& quad : render_pass->quad_list)
       DCHECK(quad->shared_quad_state);
     DCHECK(frame->render_passes_by_id.find(render_pass->id) !=
            frame->render_passes_by_id.end());
   }
 #endif
   DCHECK(frame->render_passes.back()->output_rect.origin().IsOrigin());
 
   if (!active_tree_->has_transparent_background()) {
     frame->render_passes.back()->has_transparent_background = false;
     AppendQuadsToFillScreen(
         active_tree_->RootScrollLayerDeviceViewportBounds(),
-        frame->render_passes.back(),
-        active_tree_->root_layer(),
-        active_tree_->background_color(),
-        occlusion_tracker);
+        frame->render_passes.back(), active_tree_->root_layer(),
+        active_tree_->background_color(), unoccluded_screen_space_region);
   }
 
   RemoveRenderPasses(CullRenderPassesWithNoQuads(), frame);
   renderer_->DecideRenderPassAllocationsForFrame(frame->render_passes);
 
   // Any copy requests left in the tree are not going to get serviced, and
   // should be aborted.
   ScopedPtrVector<CopyOutputRequest> requests_to_abort;
   while (!active_tree_->LayersWithCopyOutputRequest().empty()) {
     LayerImpl* layer = active_tree_->LayersWithCopyOutputRequest().back();
@@ skipping 2571 matching lines @@
     (*it)->OnSetNeedsRedrawOnImpl();
 }
 
 void LayerTreeHostImpl::NotifySwapPromiseMonitorsOfForwardingToMainThread() {
   std::set<SwapPromiseMonitor*>::iterator it = swap_promise_monitor_.begin();
   for (; it != swap_promise_monitor_.end(); it++)
     (*it)->OnForwardScrollUpdateToMainThreadOnImpl();
 }
 
 }  // namespace cc