Part 8 of cc/ directory shuffles: resources

cc/tile_priority.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/tile_priority.h"
-
-#include "base/values.h"
-#include "cc/base/math_util.h"
-
-namespace {
-
-// TODO(qinmin): modify ui/range/Range.h to support template so that we
-// don't need to define this.
-struct Range {
-  Range(float start, float end) : start_(start), end_(end) {}
-  bool IsEmpty();
-  float start_;
-  float end_;
-};
-
-inline bool Intersects(const Range& a, const Range& b) {
-  return a.start_ < b.end_ && b.start_ < a.end_;
-}
-
-inline Range Intersect(const Range& a, const Range& b) {
-  return Range(std::max(a.start_, b.start_), std::min(a.end_, b.end_));
-}
-
-bool Range::IsEmpty() {
-  return start_ >= end_;
-}
-
-inline void IntersectNegativeHalfplane(Range& out, float previous,
-    float current, float target, float time_delta) {
-  float time_per_dist = time_delta / (current - previous);
-  float t = (target - current) * time_per_dist;
-  if (time_per_dist > 0.0f)
-    out.start_ = std::max(out.start_, t);
-  else
-    out.end_ = std::min(out.end_, t);
-}
-
-inline void IntersectPositiveHalfplane(Range& out, float previous,
-    float current, float target, float time_delta) {
-  float time_per_dist = time_delta / (current - previous);
-  float t = (target - current) * time_per_dist;
-  if (time_per_dist < 0.0f)
-    out.start_ = std::max(out.start_, t);
-  else
-    out.end_ = std::min(out.end_, t);
-}
-
-}  // namespace
-
-namespace cc {
-
-const float TilePriority::kMaxDistanceInContentSpace = 4096.0f;
-
-// At 256x256 tiles, 128 tiles cover an area of 2048x4096 pixels.
-const int64 TilePriority::
-    kNumTilesToCoverWithInflatedViewportRectForPrioritization = 128;
-
-scoped_ptr<base::Value> WhichTreeAsValue(WhichTree tree) {
-  switch (tree) {
-  case ACTIVE_TREE:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "ACTIVE_TREE"));
-  case PENDING_TREE:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "PENDING_TREE"));
-  default:
-      DCHECK(false) << "Unrecognized WhichTree value " << tree;
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "<unknown WhichTree value>"));
-  }
-}
-
-scoped_ptr<base::Value> TileResolutionAsValue(
-    TileResolution resolution) {
-  switch (resolution) {
-  case LOW_RESOLUTION:
-    return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-        "LOW_RESOLUTION"));
-  case HIGH_RESOLUTION:
-    return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-        "HIGH_RESOLUTION"));
-  case NON_IDEAL_RESOLUTION:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-        "NON_IDEAL_RESOLUTION"));
-  default:
-    DCHECK(false) << "Unrecognized TileResolution value " << resolution;
-    return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-        "<unknown TileResolution value>"));
-  }
-}
-
-scoped_ptr<base::Value> TilePriority::AsValue() const {
-  scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
-  state->SetBoolean("is_live", is_live);
-  state->Set("resolution", TileResolutionAsValue(resolution).release());
-  state->Set("time_to_visible_in_seconds", MathUtil::AsValueSafely(time_to_visible_in_seconds).release());
-  state->Set("distance_to_visible_in_pixels", MathUtil::AsValueSafely(distance_to_visible_in_pixels).release());
-  state->Set("current_screen_quad", MathUtil::AsValue(current_screen_quad).release());
-  return state.PassAs<base::Value>();
-}
-
-float TilePriority::TimeForBoundsToIntersect(const gfx::RectF& previous_bounds,
-                                             const gfx::RectF& current_bounds,
-                                             float time_delta,
-                                             const gfx::RectF& target_bounds) {
-  // Perform an intersection test explicitly between current and target.
-  if (current_bounds.x() < target_bounds.right() &&
-      current_bounds.y() < target_bounds.bottom() &&
-      target_bounds.x() < current_bounds.right() &&
-      target_bounds.y() < current_bounds.bottom())
-    return 0.0f;
-
-  const float kMaxTimeToVisibleInSeconds =
-      std::numeric_limits<float>::infinity();
-
-  if (time_delta == 0.0f)
-    return kMaxTimeToVisibleInSeconds;
-
-  // As we are trying to solve the case of both scaling and scrolling, using
-  // a single coordinate with velocity is not enough. The logic here is to
-  // calculate the velocity for each edge. Then we calculate the time range that
-  // each edge will stay on the same side of the target bounds. If there is an
-  // overlap between these time ranges, the bounds must have intersect with
-  // each other during that period of time.
-  Range range(0.0f, kMaxTimeToVisibleInSeconds);
-  IntersectPositiveHalfplane(
-      range, previous_bounds.x(), current_bounds.x(),
-      target_bounds.right(), time_delta);
-  IntersectNegativeHalfplane(
-      range, previous_bounds.right(), current_bounds.right(),
-      target_bounds.x(), time_delta);
-  IntersectPositiveHalfplane(
-      range, previous_bounds.y(), current_bounds.y(),
-      target_bounds.bottom(), time_delta);
-  IntersectNegativeHalfplane(
-      range, previous_bounds.bottom(), current_bounds.bottom(),
-      target_bounds.y(), time_delta);
-  return range.IsEmpty() ? kMaxTimeToVisibleInSeconds : range.start_;
-}
-
-scoped_ptr<base::Value> TileMemoryLimitPolicyAsValue(
-    TileMemoryLimitPolicy policy) {
-  switch (policy) {
-  case ALLOW_NOTHING:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "ALLOW_NOTHING"));
-  case ALLOW_ABSOLUTE_MINIMUM:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "ALLOW_ABSOLUTE_MINIMUM"));
-  case ALLOW_PREPAINT_ONLY:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "ALLOW_PREPAINT_ONLY"));
-  case ALLOW_ANYTHING:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "ALLOW_ANYTHING"));
-  default:
-      DCHECK(false) << "Unrecognized policy value";
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "<unknown>"));
-  }
-}
-
-scoped_ptr<base::Value> TreePriorityAsValue(TreePriority prio) {
-  switch (prio) {
-  case SAME_PRIORITY_FOR_BOTH_TREES:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "SAME_PRIORITY_FOR_BOTH_TREES"));
-  case SMOOTHNESS_TAKES_PRIORITY:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "SMOOTHNESS_TAKES_PRIORITY"));
-  case NEW_CONTENT_TAKES_PRIORITY:
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "NEW_CONTENT_TAKES_PRIORITY"));
-  default:
-      DCHECK(false) << "Unrecognized priority value " << prio;
-      return scoped_ptr<base::Value>(base::Value::CreateStringValue(
-          "<unknown>"));
-  }
-}
-
-scoped_ptr<base::Value> GlobalStateThatImpactsTilePriority::AsValue() const {
-  scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
-  state->Set("memory_limit_policy", TileMemoryLimitPolicyAsValue(memory_limit_policy).release());
-  state->SetInteger("memory_limit_in_bytes", memory_limit_in_bytes);
-  state->Set("tree_priority", TreePriorityAsValue(tree_priority).release());
-  return state.PassAs<base::Value>();
-}
-
-
-}  // namespace cc