components/viz/client/local_surface_id_provider.cc

// Copyright 2017 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 "components/viz/client/local_surface_id_provider.h"
#include "cc/output/compositor_frame.h"

namespace viz {

LocalSurfaceIdProvider::LocalSurfaceIdProvider() = default;

LocalSurfaceIdProvider::~LocalSurfaceIdProvider() = default;

DefaultLocalSurfaceIdProvider::DefaultLocalSurfaceIdProvider() = default;

const cc::LocalSurfaceId&
DefaultLocalSurfaceIdProvider::GetLocalSurfaceIdForFrame(
    const cc::CompositorFrame& frame) {
  gfx::Size frame_size = frame.render_pass_list.back()->output_rect.size();
  if (!local_surface_id_.is_valid() || surface_size_ != frame_size ||
      frame.metadata.device_scale_factor != device_scale_factor_) {
    local_surface_id_ = local_surface_id_allocator_.GenerateId();
  }
  surface_size_ = frame_size;
  device_scale_factor_ = frame.metadata.device_scale_factor;
  return local_surface_id_;
}

}  // namespace viz