cc/resources/picture.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/resources/picture.h"
   6
   7 #include <algorithm>
   8 #include <limits>
   9 #include <set>
  10
  11 #include "base/base64.h"
  12 #include "base/debug/trace_event.h"
  13 #include "base/values.h"
  14 #include "cc/base/math_util.h"
  15 #include "cc/base/util.h"
  16 #include "cc/debug/traced_picture.h"
  17 #include "cc/debug/traced_value.h"
  18 #include "cc/layers/content_layer_client.h"
  19 #include "skia/ext/pixel_ref_utils.h"
  20 #include "third_party/skia/include/core/SkCanvas.h"
  21 #include "third_party/skia/include/core/SkData.h"
  22 #include "third_party/skia/include/core/SkDrawFilter.h"
  23 #include "third_party/skia/include/core/SkPaint.h"
  24 #include "third_party/skia/include/core/SkStream.h"
  25 #include "third_party/skia/include/utils/SkPictureUtils.h"
  26 #include "ui/gfx/codec/jpeg_codec.h"
  27 #include "ui/gfx/codec/png_codec.h"
  28 #include "ui/gfx/rect_conversions.h"
  29 #include "ui/gfx/skia_util.h"
  30
  31 namespace cc {
  32
  33 namespace {
  34
  35 SkData* EncodeBitmap(size_t* offset, const SkBitmap& bm) {
  36   const int kJpegQuality = 80;
  37   std::vector<unsigned char> data;
  38
  39   // If bitmap is opaque, encode as JPEG.
  40   // Otherwise encode as PNG.
  41   bool encoding_succeeded = false;
  42   if (bm.isOpaque()) {
  43     SkAutoLockPixels lock_bitmap(bm);
  44     if (bm.empty())
  45       return NULL;
  46
  47     encoding_succeeded = gfx::JPEGCodec::Encode(
  48         reinterpret_cast<unsigned char*>(bm.getAddr32(0, 0)),
  49         gfx::JPEGCodec::FORMAT_SkBitmap,
  50         bm.width(),
  51         bm.height(),
  52         bm.rowBytes(),
  53         kJpegQuality,
  54         &data);
  55   } else {
  56     encoding_succeeded = gfx::PNGCodec::EncodeBGRASkBitmap(bm, false, &data);
  57   }
  58
  59   if (encoding_succeeded) {
  60     *offset = 0;
  61     return SkData::NewWithCopy(&data.front(), data.size());
  62   }
  63   return NULL;
  64 }
  65
  66 bool DecodeBitmap(const void* buffer, size_t size, SkBitmap* bm) {
  67   const unsigned char* data = static_cast<const unsigned char *>(buffer);
  68
  69   // Try PNG first.
  70   if (gfx::PNGCodec::Decode(data, size, bm))
  71     return true;
  72
  73   // Try JPEG.
  74   scoped_ptr<SkBitmap> decoded_jpeg(gfx::JPEGCodec::Decode(data, size));
  75   if (decoded_jpeg) {
  76     *bm = *decoded_jpeg;
  77     return true;
  78   }
  79   return false;
  80 }
  81
  82 }  // namespace
  83
  84 scoped_refptr<Picture> Picture::Create(const gfx::Rect& layer_rect) {
  85   return make_scoped_refptr(new Picture(layer_rect));
  86 }
  87
  88 Picture::Picture(const gfx::Rect& layer_rect)
  89   : layer_rect_(layer_rect),
  90     cell_size_(layer_rect.size()) {
  91   // Instead of recording a trace event for object creation here, we wait for
  92   // the picture to be recorded in Picture::Record.
  93 }
  94
  95 scoped_refptr<Picture> Picture::CreateFromSkpValue(const base::Value* value) {
  96   // Decode the picture from base64.
  97   std::string encoded;
  98   if (!value->GetAsString(&encoded))
  99     return NULL;
 100
 101   std::string decoded;
 102   base::Base64Decode(encoded, &decoded);
 103   SkMemoryStream stream(decoded.data(), decoded.size());
 104
 105   // Read the picture. This creates an empty picture on failure.
 106   SkPicture* skpicture = SkPicture::CreateFromStream(&stream, &DecodeBitmap);
 107   if (skpicture == NULL)
 108     return NULL;
 109
 110   gfx::Rect layer_rect(skpicture->width(), skpicture->height());
 111   gfx::Rect opaque_rect(skpicture->width(), skpicture->height());
 112
 113   return make_scoped_refptr(new Picture(skpicture, layer_rect, opaque_rect));
 114 }
 115
 116 scoped_refptr<Picture> Picture::CreateFromValue(const base::Value* raw_value) {
 117   const base::DictionaryValue* value = NULL;
 118   if (!raw_value->GetAsDictionary(&value))
 119     return NULL;
 120
 121   // Decode the picture from base64.
 122   std::string encoded;
 123   if (!value->GetString("skp64", &encoded))
 124     return NULL;
 125
 126   std::string decoded;
 127   base::Base64Decode(encoded, &decoded);
 128   SkMemoryStream stream(decoded.data(), decoded.size());
 129
 130   const base::Value* layer_rect_value = NULL;
 131   if (!value->Get("params.layer_rect", &layer_rect_value))
 132     return NULL;
 133
 134   gfx::Rect layer_rect;
 135   if (!MathUtil::FromValue(layer_rect_value, &layer_rect))
 136     return NULL;
 137
 138   const base::Value* opaque_rect_value = NULL;
 139   if (!value->Get("params.opaque_rect", &opaque_rect_value))
 140     return NULL;
 141
 142   gfx::Rect opaque_rect;
 143   if (!MathUtil::FromValue(opaque_rect_value, &opaque_rect))
 144     return NULL;
 145
 146   // Read the picture. This creates an empty picture on failure.
 147   SkPicture* skpicture = SkPicture::CreateFromStream(&stream, &DecodeBitmap);
 148   if (skpicture == NULL)
 149     return NULL;
 150
 151   return make_scoped_refptr(new Picture(skpicture, layer_rect, opaque_rect));
 152 }
 153
 154 Picture::Picture(SkPicture* picture,
 155                  const gfx::Rect& layer_rect,
 156                  const gfx::Rect& opaque_rect) :
 157     layer_rect_(layer_rect),
 158     opaque_rect_(opaque_rect),
 159     picture_(skia::AdoptRef(picture)),
 160     cell_size_(layer_rect.size()) {
 161 }
 162
 163 Picture::Picture(const skia::RefPtr<SkPicture>& picture,
 164                  const gfx::Rect& layer_rect,
 165                  const gfx::Rect& opaque_rect,
 166                  const PixelRefMap& pixel_refs) :
 167     layer_rect_(layer_rect),
 168     opaque_rect_(opaque_rect),
 169     picture_(picture),
 170     pixel_refs_(pixel_refs),
 171     cell_size_(layer_rect.size()) {
 172 }
 173
 174 Picture::~Picture() {
 175   TRACE_EVENT_OBJECT_DELETED_WITH_ID(
 176     TRACE_DISABLED_BY_DEFAULT("cc.debug"), "cc::Picture", this);
 177 }
 178
 179 scoped_refptr<Picture> Picture::GetCloneForDrawingOnThread(
 180     unsigned thread_index) const {
 181   // SkPicture is not thread-safe to rasterize with, this returns a clone
 182   // to rasterize with on a specific thread.
 183   CHECK_GT(clones_.size(), thread_index);
 184   return clones_[thread_index];
 185 }
 186
 187 void Picture::CloneForDrawing(int num_threads) {
 188   TRACE_EVENT1("cc", "Picture::CloneForDrawing", "num_threads", num_threads);
 189
 190   DCHECK(picture_);
 191   scoped_ptr<SkPicture[]> clones(new SkPicture[num_threads]);
 192   picture_->clone(&clones[0], num_threads);
 193
 194   clones_.clear();
 195   for (int i = 0; i < num_threads; i++) {
 196     scoped_refptr<Picture> clone = make_scoped_refptr(
 197         new Picture(skia::AdoptRef(new SkPicture(clones[i])),
 198                     layer_rect_,
 199                     opaque_rect_,
 200                     pixel_refs_));
 201     clones_.push_back(clone);
 202
 203     clone->EmitTraceSnapshotAlias(this);
 204   }
 205 }
 206
 207 void Picture::Record(ContentLayerClient* painter,
 208                      const SkTileGridPicture::TileGridInfo& tile_grid_info) {
 209   TRACE_EVENT1("cc", "Picture::Record",
 210                "data", AsTraceableRecordData());
 211
 212   DCHECK(!tile_grid_info.fTileInterval.isEmpty());
 213   picture_ = skia::AdoptRef(new SkTileGridPicture(
 214       layer_rect_.width(), layer_rect_.height(), tile_grid_info));
 215
 216   SkCanvas* canvas = picture_->beginRecording(
 217       layer_rect_.width(),
 218       layer_rect_.height(),
 219       SkPicture::kUsePathBoundsForClip_RecordingFlag |
 220       SkPicture::kOptimizeForClippedPlayback_RecordingFlag);
 221
 222   canvas->save();
 223   canvas->translate(SkFloatToScalar(-layer_rect_.x()),
 224                     SkFloatToScalar(-layer_rect_.y()));
 225
 226   SkRect layer_skrect = SkRect::MakeXYWH(layer_rect_.x(),
 227                                          layer_rect_.y(),
 228                                          layer_rect_.width(),
 229                                          layer_rect_.height());
 230   canvas->clipRect(layer_skrect);
 231
 232   gfx::RectF opaque_layer_rect;
 233
 234   painter->PaintContents(canvas, layer_rect_, &opaque_layer_rect);
 235
 236   canvas->restore();
 237   picture_->endRecording();
 238
 239   opaque_rect_ = gfx::ToEnclosedRect(opaque_layer_rect);
 240
 241   EmitTraceSnapshot();
 242 }
 243
 244 void Picture::GatherPixelRefs(
 245     const SkTileGridPicture::TileGridInfo& tile_grid_info) {
 246   TRACE_EVENT2("cc", "Picture::GatherPixelRefs",
 247                "width", layer_rect_.width(),
 248                "height", layer_rect_.height());
 249
 250   DCHECK(picture_);
 251   if (!WillPlayBackBitmaps())
 252     return;
 253   cell_size_ = gfx::Size(
 254       tile_grid_info.fTileInterval.width() +
 255           2 * tile_grid_info.fMargin.width(),
 256       tile_grid_info.fTileInterval.height() +
 257           2 * tile_grid_info.fMargin.height());
 258   DCHECK_GT(cell_size_.width(), 0);
 259   DCHECK_GT(cell_size_.height(), 0);
 260
 261   int min_x = std::numeric_limits<int>::max();
 262   int min_y = std::numeric_limits<int>::max();
 263   int max_x = 0;
 264   int max_y = 0;
 265
 266   skia::DiscardablePixelRefList pixel_refs;
 267   skia::PixelRefUtils::GatherDiscardablePixelRefs(picture_.get(), &pixel_refs);
 268   for (skia::DiscardablePixelRefList::const_iterator it = pixel_refs.begin();
 269        it != pixel_refs.end();
 270        ++it) {
 271     gfx::Point min(
 272         RoundDown(static_cast<int>(it->pixel_ref_rect.x()),
 273                   cell_size_.width()),
 274         RoundDown(static_cast<int>(it->pixel_ref_rect.y()),
 275                   cell_size_.height()));
 276     gfx::Point max(
 277         RoundDown(static_cast<int>(std::ceil(it->pixel_ref_rect.right())),
 278                   cell_size_.width()),
 279         RoundDown(static_cast<int>(std::ceil(it->pixel_ref_rect.bottom())),
 280                   cell_size_.height()));
 281
 282     for (int y = min.y(); y <= max.y(); y += cell_size_.height()) {
 283       for (int x = min.x(); x <= max.x(); x += cell_size_.width()) {
 284         PixelRefMapKey key(x, y);
 285         pixel_refs_[key].push_back(it->pixel_ref);
 286       }
 287     }
 288
 289     min_x = std::min(min_x, min.x());
 290     min_y = std::min(min_y, min.y());
 291     max_x = std::max(max_x, max.x());
 292     max_y = std::max(max_y, max.y());
 293   }
 294
 295   min_pixel_cell_ = gfx::Point(min_x, min_y);
 296   max_pixel_cell_ = gfx::Point(max_x, max_y);
 297 }
 298
 299 int Picture::Raster(
 300     SkCanvas* canvas,
 301     SkDrawPictureCallback* callback,
 302     const Region& negated_content_region,
 303     float contents_scale) {
 304   TRACE_EVENT_BEGIN1(
 305       "cc",
 306       "Picture::Raster",
 307       "data",
 308       AsTraceableRasterData(contents_scale));
 309
 310   DCHECK(picture_);
 311
 312   canvas->save();
 313
 314   for (Region::Iterator it(negated_content_region); it.has_rect(); it.next())
 315     canvas->clipRect(gfx::RectToSkRect(it.rect()), SkRegion::kDifference_Op);
 316
 317   canvas->scale(contents_scale, contents_scale);
 318   canvas->translate(layer_rect_.x(), layer_rect_.y());
 319   picture_->draw(canvas, callback);
 320   SkIRect bounds;
 321   canvas->getClipDeviceBounds(&bounds);
 322   canvas->restore();
 323   TRACE_EVENT_END1(
 324       "cc", "Picture::Raster",
 325       "num_pixels_rasterized", bounds.width() * bounds.height());
 326   return bounds.width() * bounds.height();
 327 }
 328
 329 void Picture::Replay(SkCanvas* canvas) {
 330   TRACE_EVENT_BEGIN0("cc", "Picture::Replay");
 331   DCHECK(picture_);
 332
 333   picture_->draw(canvas);
 334   SkIRect bounds;
 335   canvas->getClipDeviceBounds(&bounds);
 336   TRACE_EVENT_END1("cc", "Picture::Replay",
 337                    "num_pixels_replayed", bounds.width() * bounds.height());
 338 }
 339
 340 scoped_ptr<base::Value> Picture::AsValue() const {
 341   SkDynamicMemoryWStream stream;
 342
 343   // Serialize the picture.
 344   picture_->serialize(&stream, &EncodeBitmap);
 345
 346   // Encode the picture as base64.
 347   scoped_ptr<base::DictionaryValue> res(new base::DictionaryValue());
 348   res->Set("params.layer_rect", MathUtil::AsValue(layer_rect_).release());
 349   res->Set("params.opaque_rect", MathUtil::AsValue(opaque_rect_).release());
 350
 351   size_t serialized_size = stream.bytesWritten();
 352   scoped_ptr<char[]> serialized_picture(new char[serialized_size]);
 353   stream.copyTo(serialized_picture.get());
 354   std::string b64_picture;
 355   base::Base64Encode(std::string(serialized_picture.get(), serialized_size),
 356                      &b64_picture);
 357   res->SetString("skp64", b64_picture);
 358   return res.PassAs<base::Value>();
 359 }
 360
 361 void Picture::EmitTraceSnapshot() {
 362   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(TRACE_DISABLED_BY_DEFAULT("cc.debug"),
 363       "cc::Picture", this, TracedPicture::AsTraceablePicture(this));
 364 }
 365
 366 void Picture::EmitTraceSnapshotAlias(Picture* original) {
 367   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
 368       TRACE_DISABLED_BY_DEFAULT("cc.debug"),
 369       "cc::Picture",
 370       this,
 371       TracedPicture::AsTraceablePictureAlias(original));
 372 }
 373
 374 base::LazyInstance<Picture::PixelRefs>
 375     Picture::PixelRefIterator::empty_pixel_refs_;
 376
 377 Picture::PixelRefIterator::PixelRefIterator()
 378     : picture_(NULL),
 379       current_pixel_refs_(empty_pixel_refs_.Pointer()),
 380       current_index_(0),
 381       min_point_(-1, -1),
 382       max_point_(-1, -1),
 383       current_x_(0),
 384       current_y_(0) {
 385 }
 386
 387 Picture::PixelRefIterator::PixelRefIterator(
 388     const gfx::Rect& rect,
 389     const Picture* picture)
 390     : picture_(picture),
 391       current_pixel_refs_(empty_pixel_refs_.Pointer()),
 392       current_index_(0) {
 393   gfx::Rect layer_rect = picture->layer_rect_;
 394   gfx::Size cell_size = picture->cell_size_;
 395   DCHECK(!cell_size.IsEmpty());
 396
 397   gfx::Rect query_rect(rect);
 398   // Early out if the query rect doesn't intersect this picture.
 399   if (!query_rect.Intersects(layer_rect)) {
 400     min_point_ = gfx::Point(0, 0);
 401     max_point_ = gfx::Point(0, 0);
 402     current_x_ = 1;
 403     current_y_ = 1;
 404     return;
 405   }
 406
 407   // First, subtract the layer origin as cells are stored in layer space.
 408   query_rect.Offset(-layer_rect.OffsetFromOrigin());
 409
 410   // We have to find a cell_size aligned point that corresponds to
 411   // query_rect. Point is a multiple of cell_size.
 412   min_point_ = gfx::Point(
 413       RoundDown(query_rect.x(), cell_size.width()),
 414       RoundDown(query_rect.y(), cell_size.height()));
 415   max_point_ = gfx::Point(
 416       RoundDown(query_rect.right() - 1, cell_size.width()),
 417       RoundDown(query_rect.bottom() - 1, cell_size.height()));
 418
 419   // Limit the points to known pixel ref boundaries.
 420   min_point_ = gfx::Point(
 421       std::max(min_point_.x(), picture->min_pixel_cell_.x()),
 422       std::max(min_point_.y(), picture->min_pixel_cell_.y()));
 423   max_point_ = gfx::Point(
 424       std::min(max_point_.x(), picture->max_pixel_cell_.x()),
 425       std::min(max_point_.y(), picture->max_pixel_cell_.y()));
 426
 427   // Make the current x be cell_size.width() less than min point, so that
 428   // the first increment will point at min_point_.
 429   current_x_ = min_point_.x() - cell_size.width();
 430   current_y_ = min_point_.y();
 431   if (current_y_ <= max_point_.y())
 432     ++(*this);
 433 }
 434
 435 Picture::PixelRefIterator::~PixelRefIterator() {
 436 }
 437
 438 Picture::PixelRefIterator& Picture::PixelRefIterator::operator++() {
 439   ++current_index_;
 440   // If we're not at the end of the list, then we have the next item.
 441   if (current_index_ < current_pixel_refs_->size())
 442     return *this;
 443
 444   DCHECK(current_y_ <= max_point_.y());
 445   while (true) {
 446     gfx::Size cell_size = picture_->cell_size_;
 447
 448     // Advance the current grid cell.
 449     current_x_ += cell_size.width();
 450     if (current_x_ > max_point_.x()) {
 451       current_y_ += cell_size.height();
 452       current_x_ = min_point_.x();
 453       if (current_y_ > max_point_.y()) {
 454         current_pixel_refs_ = empty_pixel_refs_.Pointer();
 455         current_index_ = 0;
 456         break;
 457       }
 458     }
 459
 460     // If there are no pixel refs at this grid cell, keep incrementing.
 461     PixelRefMapKey key(current_x_, current_y_);
 462     PixelRefMap::const_iterator iter = picture_->pixel_refs_.find(key);
 463     if (iter == picture_->pixel_refs_.end())
 464       continue;
 465
 466     // We found a non-empty list: store it and get the first pixel ref.
 467     current_pixel_refs_ = &iter->second;
 468     current_index_ = 0;
 469     break;
 470   }
 471   return *this;
 472 }
 473
 474 scoped_refptr<base::debug::ConvertableToTraceFormat>
 475     Picture::AsTraceableRasterData(float scale) const {
 476   scoped_ptr<base::DictionaryValue> raster_data(new base::DictionaryValue());
 477   raster_data->Set("picture_id", TracedValue::CreateIDRef(this).release());
 478   raster_data->SetDouble("scale", scale);
 479   return TracedValue::FromValue(raster_data.release());
 480 }
 481
 482 scoped_refptr<base::debug::ConvertableToTraceFormat>
 483     Picture::AsTraceableRecordData() const {
 484   scoped_ptr<base::DictionaryValue> record_data(new base::DictionaryValue());
 485   record_data->Set("picture_id", TracedValue::CreateIDRef(this).release());
 486   record_data->SetInteger("width", layer_rect_.width());
 487   record_data->SetInteger("height", layer_rect_.height());
 488   return TracedValue::FromValue(record_data.release());
 489 }
 490
 491 }  // namespace cc