Initial checkin of the new Mozart compositor.

services/gfx/compositor/graph/node_def.cc

+// Copyright 2015 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 "services/gfx/compositor/graph/node_def.h"
+
+#include <sstream>
+
+#include "base/logging.h"
+#include "mojo/services/gfx/composition/cpp/logging.h"
+#include "services/gfx/compositor/graph/scene_def.h"
+#include "services/gfx/compositor/graph/snapshot.h"
+#include "services/gfx/compositor/render/render_image.h"
+#include "services/gfx/compositor/render/render_layer.h"
+
+namespace compositor {
+
+// TODO(jeffbrown): Move these conversion functions somewhere more useful.

[abarth, 2016/01/10 22:55:36]

There's a converters directory in mojo/common.  Maybe we should add some
converters to mojo/skia?

[jeffbrown, 2016/01/16 03:28:32]

Yeah... but maybe later.  :)

+
+static SkRect ToSkRect(const mojo::Rect& rect) {

[abarth, 2016/01/10 22:55:36]

The mojo types have template magic to make these sorts of converters easier.

+  return SkRect::MakeXYWH(rect.x, rect.y, rect.width, rect.height);
+}
+
+static SkRRect ToSkRRect(const mojo::RRect& rrect) {
+  SkVector radii[4] = {
+      {rrect.top_left_radius_x, rrect.top_left_radius_y},
+      {rrect.top_right_radius_x, rrect.top_right_radius_y},
+      {rrect.bottom_left_radius_x, rrect.bottom_left_radius_y},
+      {rrect.bottom_right_radius_x, rrect.bottom_right_radius_y}};
+  SkRRect result;
+  result.setRectRadii(
+      SkRect::MakeXYWH(rrect.x, rrect.y, rrect.width, rrect.height), radii);

[abarth, 2016/01/10 22:55:35]

Note that this routine is more expensive that setRectXY, which is by far the
more common use case.

[jeffbrown, 2016/01/16 03:28:32]

Yes, but we don't know whether we're in the fast case yet without checking. 
Fortunately Skia checks this for us so I think it's a wash.

+  return result;
+}
+
+static SkMatrix ToSkMatrix(const mojo::Transform& transform) {
+  // TODO(jeffbrown): What to do with the Z components?
+  // Perhaps we need a simpler 2D transform matrix mojom.

[abarth, 2016/01/10 22:55:36]

This is the same thing we do in Flutter.  We can talk to the Skia folks about
it, but it'll work fine for a while.

[jeffbrown, 2016/01/16 03:28:32]

Acknowledged.

+  SkMatrix result;
+  result.setAll(transform.matrix[0], transform.matrix[1], transform.matrix[3],
+                transform.matrix[4], transform.matrix[5], transform.matrix[7],
+                transform.matrix[12], transform.matrix[13],
+                transform.matrix[15]);
+  return result;
+}
+
+static SkColor ToSkColor(const mojo::gfx::composition::Color& color) {
+  return SkColorSetARGBInline(color.alpha, color.red, color.green, color.blue);
+}
+
+static SkPath ToSkPath(const mojo::gfx::composition::Clip& clip) {
+  SkPath result;
+  if (clip.is_rect()) {
+    result.addRect(ToSkRect(*clip.get_rect()));

[abarth, 2016/01/10 22:55:36]

Woah there.  I haven't seen where you're using this function, but the codepath
for Rect should be very different from the RRect and Path code paths.  Rect
clips can be done much more efficiently if you use the Rect-specific codepath in
Skia.

[jeffbrown, 2016/01/16 03:28:32]

Dropping RRect clips for now.

+  } else if (clip.is_rect()) {
+    result.addRRect(ToSkRRect(*clip.get_rrect()));
+  } else {
+    DCHECK(false);  // was checked during validation
+  }
+  return result;
+}
+
+static SkPaint ToSkPaint(const mojo::gfx::composition::Blend& blend) {
+  SkPaint result;
+  result.setAlpha(blend.alpha);
+  return result;
+}
+
+NodeDef::NodeDef(uint32_t node_id,
+                 mojo::TransformPtr content_transform,
+                 mojo::gfx::composition::ClipPtr content_clip,
+                 uint32_t hit_id,
+                 Combinator combinator,
+                 const std::vector<uint32_t>& child_node_ids,
+                 NodeOp* op)
+    : node_id_(node_id),
+      content_transform_(content_transform.Pass()),
+      content_clip_(content_clip.Pass()),
+      hit_id_(hit_id),
+      combinator_(combinator),
+      child_node_ids_(child_node_ids),
+      op_(op) {}
+
+NodeDef::~NodeDef() {}
+
+bool NodeDef::Validate(SceneDef* scene, std::ostream& err) {
+  if (content_clip_) {
+    if (!content_clip_->is_rect() && !content_clip_->is_rrect()) {
+      err << "Node contains unsupported content clip type: "
+          << FormattedLabel(scene);
+      return false;
+    }
+  }
+
+  child_nodes_.clear();
+  for (uint32_t child_node_id : child_node_ids_) {
+    NodeDef* child_node = scene->FindNode(child_node_id);
+    if (!child_node) {
+      err << "Node refers to unknown child: " << FormattedLabel(scene)
+          << ", child_node_id=" << child_node_id;
+      return false;
+    }
+    child_nodes_.push_back(child_node);
+  }
+
+  return !op_ || op_->Validate(scene, this, err);
+}
+
+bool NodeDef::Snapshot(SnapshotBuilder* snapshot_builder,
+                       RenderLayerBuilder* layer_builder,
+                       SceneDef* scene) {
+  DCHECK(snapshot_builder);
+  DCHECK(layer_builder);
+  DCHECK(scene);
+
+  // Detect cycles.
+  if (visited_) {
+    if (snapshot_builder->block_log()) {
+      *snapshot_builder->block_log()
+          << "Node blocked due to recursive cycle: " << FormattedLabel(scene)
+          << std::endl;
+    }
+    return false;
+  }
+
+  // Snapshot the contents of the node.
+  visited_ = true;
+  bool success = SnapshotInner(snapshot_builder, layer_builder, scene);
+  visited_ = false;
+  return success;
+}
+
+bool NodeDef::SnapshotInner(SnapshotBuilder* snapshot_builder,
+                            RenderLayerBuilder* layer_builder,
+                            SceneDef* scene) {
+  // TODO(jeffbrown): Frequently referenced and reused nodes, especially
+  // layer nodes, may benefit from caching.
+  layer_builder->PushNode(
+      node_id_, hit_id_,
+      content_transform_ ? ToSkMatrix(*content_transform_) : SkMatrix::I(),
+      content_clip_ ? ToSkPath(*content_clip_) : SkPath());
+
+  bool success =
+      op_ ? op_->Snapshot(snapshot_builder, layer_builder, scene, this)
+          : SnapshotChildren(snapshot_builder, layer_builder, scene);
+  if (!success)
+    return false;
+
+  layer_builder->PopNode();
+  return true;
+}
+
+bool NodeDef::SnapshotChildren(SnapshotBuilder* snapshot_builder,
+                               RenderLayerBuilder* layer_builder,
+                               SceneDef* scene) {
+  DCHECK(snapshot_builder);
+  DCHECK(layer_builder);
+  DCHECK(scene);
+
+  switch (combinator_) {
+    // MERGE: All or nothing.
+    case Combinator::MERGE: {
+      for (NodeDef* child_node : child_nodes_) {
+        if (!child_node->Snapshot(snapshot_builder, layer_builder, scene)) {
+          if (snapshot_builder->block_log()) {
+            *snapshot_builder->block_log()
+                << "Node with MERGE combinator blocked since "
+                   "one of its children is blocked: "
+                << FormattedLabel(scene) << ", blocked child "
+                << child_node->FormattedLabel(scene) << std::endl;
+          }
+          return false;  // blocked
+        }
+      }
+      return true;
+    }
+
+    // PRUNE: Silently discard blocked children.
+    case Combinator::PRUNE: {
+      for (NodeDef* child_node : child_nodes_) {
+        RenderLayerBuilder child_layer_builder;
+        if (child_node->Snapshot(snapshot_builder, &child_layer_builder,
+                                 scene)) {
+          layer_builder->DrawLayer(child_layer_builder.Build());
+        }
+      }
+      return true;
+    }
+
+    // FALLBACK: Keep only the first unblocked child.
+    case Combinator::FALLBACK: {
+      if (child_nodes_.empty())
+        return true;
+      for (NodeDef* child_node : child_nodes_) {
+        RenderLayerBuilder child_layer_builder;
+        if (child_node->Snapshot(snapshot_builder, &child_layer_builder,
+                                 scene)) {
+          layer_builder->DrawLayer(child_layer_builder.Build());
+          return true;
+        }
+      }
+      if (snapshot_builder->block_log()) {
+        *snapshot_builder->block_log()
+            << "Node with FALLBACK combinator blocked since "
+               "all of its children are blocked: "
+            << FormattedLabel(scene) << std::endl;
+      }
+      return false;  // blocked
+    }
+  }
+}
+
+std::string NodeDef::FormattedLabel(SceneDef* scene) {
+  std::ostringstream s;
+  s << scene->FormattedLabel() << "[" << node_id_ << "]";
+  return s.str();

[abarth, 2016/01/10 22:55:35]

base::StringPrintf

[jeffbrown, 2016/01/16 03:28:32]

Done.

+}
+
+bool NodeOp::Validate(SceneDef* scene, NodeDef* node, std::ostream& err) {
+  return true;
+}
+
+RectNodeOp::RectNodeOp(const mojo::Rect& content_rect,
+                       const mojo::gfx::composition::Color& color)
+    : content_rect_(content_rect), color_(color) {}
+
+RectNodeOp::~RectNodeOp() {}
+
+bool RectNodeOp::Snapshot(SnapshotBuilder* snapshot_builder,
+                          RenderLayerBuilder* layer_builder,
+                          SceneDef* scene,
+                          NodeDef* node) {
+  if (!node->SnapshotChildren(snapshot_builder, layer_builder, scene))
+    return false;
+
+  SkPaint paint;
+  paint.setColor(ToSkColor(color_));
+  layer_builder->DrawRect(ToSkRect(content_rect_), paint);
+  return true;
+}
+
+ImageNodeOp::ImageNodeOp(const mojo::Rect& content_rect,
+                         mojo::RectPtr image_rect,
+                         uint32 image_resource_id,
+                         mojo::gfx::composition::BlendPtr blend)
+    : content_rect_(content_rect),
+      image_rect_(image_rect.Pass()),
+      image_resource_id_(image_resource_id),
+      blend_(blend.Pass()) {}
+
+ImageNodeOp::~ImageNodeOp() {}
+
+bool ImageNodeOp::Validate(SceneDef* scene, NodeDef* node, std::ostream& err) {
+  image_resource_ = scene->FindImageResource(image_resource_id_);
+  if (!image_resource_) {
+    err << "Node refers to unknown or invalid image resource: "
+        << node->FormattedLabel(scene)
+        << ", image_resource_id=" << image_resource_id_;
+    return false;
+  }
+  return true;
+}
+
+bool ImageNodeOp::Snapshot(SnapshotBuilder* snapshot_builder,
+                           RenderLayerBuilder* layer_builder,
+                           SceneDef* scene,
+                           NodeDef* node) {
+  DCHECK(image_resource_);
+
+  if (!image_resource_->image()) {
+    if (snapshot_builder->block_log()) {
+      *snapshot_builder->block_log()
+          << "Node blocked due to its referenced image "
+             "resource being unavailable: "
+          << node->FormattedLabel(scene) << std::endl;
+    }
+    return false;
+  }
+
+  if (!node->SnapshotChildren(snapshot_builder, layer_builder, scene))
+    return false;
+
+  layer_builder->DrawImage(
+      image_resource_->image(), ToSkRect(content_rect_),
+      image_rect_ ? ToSkRect(*image_rect_)
+                  : SkRect::MakeWH(image_resource_->image()->width(),
+                                   image_resource_->image()->height()),
+      blend_ ? ToSkPaint(*blend_) : SkPaint());
+  return true;
+}
+
+SceneNodeOp::SceneNodeOp(uint32_t scene_resource_id, uint32_t scene_version)
+    : scene_resource_id_(scene_resource_id), scene_version_(scene_version) {}
+
+SceneNodeOp::~SceneNodeOp() {}
+
+bool SceneNodeOp::Validate(SceneDef* scene, NodeDef* node, std::ostream& err) {
+  scene_resource_ = scene->FindSceneResource(scene_resource_id_);
+  if (!scene_resource_) {
+    err << "Node refers to unknown or invalid scene resource: "
+        << node->FormattedLabel(scene)
+        << ", scene_resource_id=" << scene_resource_id_;
+    return false;
+  }
+  return true;
+}
+
+bool SceneNodeOp::Snapshot(SnapshotBuilder* snapshot_builder,
+                           RenderLayerBuilder* layer_builder,
+                           SceneDef* scene,
+                           NodeDef* node) {
+  DCHECK(scene_resource_);
+
+  SceneDef* referenced_scene = scene_resource_->referenced_scene();
+  if (!referenced_scene) {
+    if (snapshot_builder->block_log()) {
+      *snapshot_builder->block_log()
+          << "Node blocked due to its referenced scene "
+             "resource being unavailable: "
+          << node->FormattedLabel(scene) << std::endl;
+    }
+    return false;
+  }
+
+  uint32_t actual_version = referenced_scene->version();
+  if (scene_version_ != mojo::gfx::composition::kSceneVersionNone &&
+      actual_version != mojo::gfx::composition::kSceneVersionNone &&
+      scene_version_ != actual_version) {
+    if (snapshot_builder->block_log()) {
+      *snapshot_builder->block_log()
+          << "Node blocked due to its referenced scene "
+             "resource not having the desired version: "
+          << node->FormattedLabel(scene)
+          << ", requested_version=" << scene_version_
+          << ", actual_version=" << actual_version << std::endl;
+    }
+    return false;
+  }
+
+  if (!node->SnapshotChildren(snapshot_builder, layer_builder, scene))
+    return false;
+
+  return referenced_scene->Snapshot(snapshot_builder, layer_builder);
+}
+
+LayerNodeOp::LayerNodeOp(const mojo::Size& size,
+                         mojo::gfx::composition::BlendPtr blend)
+    : size_(size), blend_(blend.Pass()) {}
+
+LayerNodeOp::~LayerNodeOp() {}
+
+bool LayerNodeOp::Snapshot(SnapshotBuilder* snapshot_builder,
+                           RenderLayerBuilder* layer_builder,
+                           SceneDef* scene,
+                           NodeDef* node) {
+  SkRect content_rect = SkRect::MakeWH(size_.width, size_.height);
+  RenderLayerBuilder children_layer_builder(&content_rect);
+  if (!node->SnapshotChildren(snapshot_builder, &children_layer_builder, scene))
+    return false;
+
+  layer_builder->DrawSavedLayer(children_layer_builder.Build(), content_rect,
+                                blend_ ? ToSkPaint(*blend_) : SkPaint());
+  return true;
+}
+
+}  // namespace compositor