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/debug/trace_event_argument.h"
  14 #include "base/values.h"
  15 #include "cc/base/math_util.h"
  16 #include "cc/base/util.h"
  17 #include "cc/debug/picture_debug_util.h"
  18 #include "cc/debug/traced_picture.h"
  19 #include "cc/debug/traced_value.h"
  20 #include "cc/layers/content_layer_client.h"
  21 #include "skia/ext/pixel_ref_utils.h"
  22 #include "third_party/skia/include/core/SkCanvas.h"
  23 #include "third_party/skia/include/core/SkDrawPictureCallback.h"
  24 #include "third_party/skia/include/core/SkPaint.h"
  25 #include "third_party/skia/include/core/SkPictureRecorder.h"
  26 #include "third_party/skia/include/core/SkStream.h"
  27 #include "third_party/skia/include/utils/SkNullCanvas.h"
  28 #include "third_party/skia/include/utils/SkPictureUtils.h"
  29 #include "ui/gfx/codec/jpeg_codec.h"
  30 #include "ui/gfx/codec/png_codec.h"
  31 #include "ui/gfx/geometry/rect_conversions.h"
  32 #include "ui/gfx/skia_util.h"
  33
  34 namespace cc {
  35
  36 namespace {
  37
  38 bool DecodeBitmap(const void* buffer, size_t size, SkBitmap* bm) {
  39   const unsigned char* data = static_cast<const unsigned char *>(buffer);
  40
  41   // Try PNG first.
  42   if (gfx::PNGCodec::Decode(data, size, bm))
  43     return true;
  44
  45   // Try JPEG.
  46   scoped_ptr<SkBitmap> decoded_jpeg(gfx::JPEGCodec::Decode(data, size));
  47   if (decoded_jpeg) {
  48     *bm = *decoded_jpeg;
  49     return true;
  50   }
  51   return false;
  52 }
  53
  54 }  // namespace
  55
  56 scoped_refptr<Picture> Picture::Create(const gfx::Rect& layer_rect,
  57                                        ContentLayerClient* client,
  58                                        const gfx::Size& tile_grid_size,
  59                                        bool gather_pixel_refs,
  60                                        RecordingMode recording_mode) {
  61   scoped_refptr<Picture> picture = make_scoped_refptr(new Picture(layer_rect));
  62
  63   picture->Record(client, tile_grid_size, recording_mode);
  64   if (gather_pixel_refs)
  65     picture->GatherPixelRefs(tile_grid_size);
  66
  67   return picture;
  68 }
  69
  70 Picture::Picture(const gfx::Rect& layer_rect)
  71   : layer_rect_(layer_rect),
  72     cell_size_(layer_rect.size()) {
  73   // Instead of recording a trace event for object creation here, we wait for
  74   // the picture to be recorded in Picture::Record.
  75 }
  76
  77 scoped_refptr<Picture> Picture::CreateFromSkpValue(const base::Value* value) {
  78   // Decode the picture from base64.
  79   std::string encoded;
  80   if (!value->GetAsString(&encoded))
  81     return NULL;
  82
  83   std::string decoded;
  84   base::Base64Decode(encoded, &decoded);
  85   SkMemoryStream stream(decoded.data(), decoded.size());
  86
  87   // Read the picture. This creates an empty picture on failure.
  88   SkPicture* skpicture = SkPicture::CreateFromStream(&stream, &DecodeBitmap);
  89   if (skpicture == NULL)
  90     return NULL;
  91
  92   gfx::Rect layer_rect(gfx::SkIRectToRect(skpicture->cullRect().roundOut()));
  93   return make_scoped_refptr(new Picture(skpicture, layer_rect));
  94 }
  95
  96 scoped_refptr<Picture> Picture::CreateFromValue(const base::Value* raw_value) {
  97   const base::DictionaryValue* value = NULL;
  98   if (!raw_value->GetAsDictionary(&value))
  99     return NULL;
 100
 101   // Decode the picture from base64.
 102   std::string encoded;
 103   if (!value->GetString("skp64", &encoded))
 104     return NULL;
 105
 106   std::string decoded;
 107   base::Base64Decode(encoded, &decoded);
 108   SkMemoryStream stream(decoded.data(), decoded.size());
 109
 110   const base::Value* layer_rect_value = NULL;
 111   if (!value->Get("params.layer_rect", &layer_rect_value))
 112     return NULL;
 113
 114   gfx::Rect layer_rect;
 115   if (!MathUtil::FromValue(layer_rect_value, &layer_rect))
 116     return NULL;
 117
 118   // Read the picture. This creates an empty picture on failure.
 119   SkPicture* skpicture = SkPicture::CreateFromStream(&stream, &DecodeBitmap);
 120   if (skpicture == NULL)
 121     return NULL;
 122
 123   return make_scoped_refptr(new Picture(skpicture, layer_rect));
 124 }
 125
 126 Picture::Picture(SkPicture* picture, const gfx::Rect& layer_rect)
 127     : layer_rect_(layer_rect),
 128       picture_(skia::AdoptRef(picture)),
 129       cell_size_(layer_rect.size()) {
 130 }
 131
 132 Picture::Picture(const skia::RefPtr<SkPicture>& picture,
 133                  const gfx::Rect& layer_rect,
 134                  const PixelRefMap& pixel_refs) :
 135     layer_rect_(layer_rect),
 136     picture_(picture),
 137     pixel_refs_(pixel_refs),
 138     cell_size_(layer_rect.size()) {
 139 }
 140
 141 Picture::~Picture() {
 142   TRACE_EVENT_OBJECT_DELETED_WITH_ID(
 143       TRACE_DISABLED_BY_DEFAULT("cc.debug.picture"), "cc::Picture", this);
 144 }
 145
 146 bool Picture::IsSuitableForGpuRasterization(const char** reason) const {
 147   DCHECK(picture_);
 148
 149   // TODO(hendrikw): SkPicture::suitableForGpuRasterization takes a GrContext.
 150   // Currently the GrContext isn't used, and should probably be removed from
 151   // skia.
 152   return picture_->suitableForGpuRasterization(nullptr, reason);
 153 }
 154
 155 int Picture::ApproximateOpCount() const {
 156   DCHECK(picture_);
 157   return picture_->approximateOpCount();
 158 }
 159
 160 size_t Picture::ApproximateMemoryUsage() const {
 161   DCHECK(picture_);
 162   return SkPictureUtils::ApproximateBytesUsed(picture_.get());
 163 }
 164
 165 bool Picture::HasText() const {
 166   DCHECK(picture_);
 167   return picture_->hasText();
 168 }
 169
 170 void Picture::Record(ContentLayerClient* painter,
 171                      const gfx::Size& tile_grid_size,
 172                      RecordingMode recording_mode) {
 173   TRACE_EVENT2("cc",
 174                "Picture::Record",
 175                "data",
 176                AsTraceableRecordData(),
 177                "recording_mode",
 178                recording_mode);
 179
 180   DCHECK(!picture_);
 181   DCHECK(!tile_grid_size.IsEmpty());
 182
 183   // TODO(mtklein): If SkRTree sticks, clean up tile_grid_info.  skbug.com/3085
 184   SkRTreeFactory factory;
 185   SkPictureRecorder recorder;
 186
 187   skia::RefPtr<SkCanvas> canvas;
 188   canvas = skia::SharePtr(recorder.beginRecording(
 189       layer_rect_.width(), layer_rect_.height(), &factory,
 190       SkPictureRecorder::kComputeSaveLayerInfo_RecordFlag));
 191
 192   ContentLayerClient::GraphicsContextStatus graphics_context_status =
 193       ContentLayerClient::GRAPHICS_CONTEXT_ENABLED;
 194
 195   switch (recording_mode) {
 196     case RECORD_NORMALLY:
 197       // Already setup for normal recording.
 198       break;
 199     case RECORD_WITH_SK_NULL_CANVAS:
 200       canvas = skia::AdoptRef(SkCreateNullCanvas());
 201       break;
 202     case RECORD_WITH_PAINTING_DISABLED:
 203       // We pass a disable flag through the paint calls when perfromance
 204       // testing (the only time this case should ever arise) when we want to
 205       // prevent the Blink GraphicsContext object from consuming any compute
 206       // time.
 207       canvas = skia::AdoptRef(SkCreateNullCanvas());
 208       graphics_context_status = ContentLayerClient::GRAPHICS_CONTEXT_DISABLED;
 209       break;
 210     default:
 211       NOTREACHED();
 212   }
 213
 214   canvas->save();
 215   canvas->translate(SkFloatToScalar(-layer_rect_.x()),
 216                     SkFloatToScalar(-layer_rect_.y()));
 217
 218   SkRect layer_skrect = SkRect::MakeXYWH(layer_rect_.x(),
 219                                          layer_rect_.y(),
 220                                          layer_rect_.width(),
 221                                          layer_rect_.height());
 222   canvas->clipRect(layer_skrect);
 223
 224   painter->PaintContents(canvas.get(), layer_rect_, graphics_context_status);
 225
 226   canvas->restore();
 227   picture_ = skia::AdoptRef(recorder.endRecording());
 228   DCHECK(picture_);
 229
 230   EmitTraceSnapshot();
 231 }
 232
 233 void Picture::GatherPixelRefs(const gfx::Size& tile_grid_size) {
 234   TRACE_EVENT2("cc", "Picture::GatherPixelRefs",
 235                "width", layer_rect_.width(),
 236                "height", layer_rect_.height());
 237
 238   DCHECK(picture_);
 239   DCHECK(pixel_refs_.empty());
 240   if (!WillPlayBackBitmaps())
 241     return;
 242   cell_size_ = tile_grid_size;
 243   DCHECK_GT(cell_size_.width(), 0);
 244   DCHECK_GT(cell_size_.height(), 0);
 245
 246   int min_x = std::numeric_limits<int>::max();
 247   int min_y = std::numeric_limits<int>::max();
 248   int max_x = 0;
 249   int max_y = 0;
 250
 251   skia::DiscardablePixelRefList pixel_refs;
 252   skia::PixelRefUtils::GatherDiscardablePixelRefs(picture_.get(), &pixel_refs);
 253   for (skia::DiscardablePixelRefList::const_iterator it = pixel_refs.begin();
 254        it != pixel_refs.end();
 255        ++it) {
 256     gfx::Point min(
 257         RoundDown(static_cast<int>(it->pixel_ref_rect.x()),
 258                   cell_size_.width()),
 259         RoundDown(static_cast<int>(it->pixel_ref_rect.y()),
 260                   cell_size_.height()));
 261     gfx::Point max(
 262         RoundDown(static_cast<int>(std::ceil(it->pixel_ref_rect.right())),
 263                   cell_size_.width()),
 264         RoundDown(static_cast<int>(std::ceil(it->pixel_ref_rect.bottom())),
 265                   cell_size_.height()));
 266
 267     for (int y = min.y(); y <= max.y(); y += cell_size_.height()) {
 268       for (int x = min.x(); x <= max.x(); x += cell_size_.width()) {
 269         PixelRefMapKey key(x, y);
 270         pixel_refs_[key].push_back(it->pixel_ref);
 271       }
 272     }
 273
 274     min_x = std::min(min_x, min.x());
 275     min_y = std::min(min_y, min.y());
 276     max_x = std::max(max_x, max.x());
 277     max_y = std::max(max_y, max.y());
 278   }
 279
 280   min_pixel_cell_ = gfx::Point(min_x, min_y);
 281   max_pixel_cell_ = gfx::Point(max_x, max_y);
 282 }
 283
 284 int Picture::Raster(SkCanvas* canvas,
 285                     SkDrawPictureCallback* callback,
 286                     const Region& negated_content_region,
 287                     float contents_scale) const {
 288   TRACE_EVENT_BEGIN1(
 289       "cc",
 290       "Picture::Raster",
 291       "data",
 292       AsTraceableRasterData(contents_scale));
 293
 294   DCHECK(picture_);
 295
 296   canvas->save();
 297
 298   for (Region::Iterator it(negated_content_region); it.has_rect(); it.next())
 299     canvas->clipRect(gfx::RectToSkRect(it.rect()), SkRegion::kDifference_Op);
 300
 301   canvas->scale(contents_scale, contents_scale);
 302   canvas->translate(layer_rect_.x(), layer_rect_.y());
 303   if (callback) {
 304     // If we have a callback, we need to call |draw()|, |drawPicture()| doesn't
 305     // take a callback.  This is used by |AnalysisCanvas| to early out.
 306     picture_->playback(canvas, callback);
 307   } else {
 308     // Prefer to call |drawPicture()| on the canvas since it could place the
 309     // entire picture on the canvas instead of parsing the skia operations.
 310     canvas->drawPicture(picture_.get());
 311   }
 312   SkIRect bounds;
 313   canvas->getClipDeviceBounds(&bounds);
 314   canvas->restore();
 315   TRACE_EVENT_END1(
 316       "cc", "Picture::Raster",
 317       "num_pixels_rasterized", bounds.width() * bounds.height());
 318   return bounds.width() * bounds.height();
 319 }
 320
 321 void Picture::Replay(SkCanvas* canvas) {
 322   TRACE_EVENT_BEGIN0("cc", "Picture::Replay");
 323   DCHECK(picture_);
 324   picture_->playback(canvas);
 325   SkIRect bounds;
 326   canvas->getClipDeviceBounds(&bounds);
 327   TRACE_EVENT_END1("cc", "Picture::Replay",
 328                    "num_pixels_replayed", bounds.width() * bounds.height());
 329 }
 330
 331 scoped_ptr<base::Value> Picture::AsValue() const {
 332   // Encode the picture as base64.
 333   scoped_ptr<base::DictionaryValue> res(new base::DictionaryValue());
 334   res->Set("params.layer_rect", MathUtil::AsValue(layer_rect_).release());
 335   std::string b64_picture;
 336   PictureDebugUtil::SerializeAsBase64(picture_.get(), &b64_picture);
 337   res->SetString("skp64", b64_picture);
 338   return res.Pass();
 339 }
 340
 341 void Picture::EmitTraceSnapshot() const {
 342   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
 343       TRACE_DISABLED_BY_DEFAULT("cc.debug.picture") ","
 344           TRACE_DISABLED_BY_DEFAULT("devtools.timeline.picture"),
 345       "cc::Picture",
 346       this,
 347       TracedPicture::AsTraceablePicture(this));
 348 }
 349
 350 void Picture::EmitTraceSnapshotAlias(Picture* original) const {
 351   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
 352       TRACE_DISABLED_BY_DEFAULT("cc.debug.picture") ","
 353           TRACE_DISABLED_BY_DEFAULT("devtools.timeline.picture"),
 354       "cc::Picture",
 355       this,
 356       TracedPicture::AsTraceablePictureAlias(original));
 357 }
 358
 359 base::LazyInstance<Picture::PixelRefs>
 360     Picture::PixelRefIterator::empty_pixel_refs_;
 361
 362 Picture::PixelRefIterator::PixelRefIterator()
 363     : picture_(NULL),
 364       current_pixel_refs_(empty_pixel_refs_.Pointer()),
 365       current_index_(0),
 366       min_point_(-1, -1),
 367       max_point_(-1, -1),
 368       current_x_(0),
 369       current_y_(0) {
 370 }
 371
 372 Picture::PixelRefIterator::PixelRefIterator(
 373     const gfx::Rect& rect,
 374     const Picture* picture)
 375     : picture_(picture),
 376       current_pixel_refs_(empty_pixel_refs_.Pointer()),
 377       current_index_(0) {
 378   gfx::Rect layer_rect = picture->layer_rect_;
 379   gfx::Size cell_size = picture->cell_size_;
 380   DCHECK(!cell_size.IsEmpty());
 381
 382   gfx::Rect query_rect(rect);
 383   // Early out if the query rect doesn't intersect this picture.
 384   if (!query_rect.Intersects(layer_rect)) {
 385     min_point_ = gfx::Point(0, 0);
 386     max_point_ = gfx::Point(0, 0);
 387     current_x_ = 1;
 388     current_y_ = 1;
 389     return;
 390   }
 391
 392   // First, subtract the layer origin as cells are stored in layer space.
 393   query_rect.Offset(-layer_rect.OffsetFromOrigin());
 394
 395   // We have to find a cell_size aligned point that corresponds to
 396   // query_rect. Point is a multiple of cell_size.
 397   min_point_ = gfx::Point(
 398       RoundDown(query_rect.x(), cell_size.width()),
 399       RoundDown(query_rect.y(), cell_size.height()));
 400   max_point_ = gfx::Point(
 401       RoundDown(query_rect.right() - 1, cell_size.width()),
 402       RoundDown(query_rect.bottom() - 1, cell_size.height()));
 403
 404   // Limit the points to known pixel ref boundaries.
 405   min_point_ = gfx::Point(
 406       std::max(min_point_.x(), picture->min_pixel_cell_.x()),
 407       std::max(min_point_.y(), picture->min_pixel_cell_.y()));
 408   max_point_ = gfx::Point(
 409       std::min(max_point_.x(), picture->max_pixel_cell_.x()),
 410       std::min(max_point_.y(), picture->max_pixel_cell_.y()));
 411
 412   // Make the current x be cell_size.width() less than min point, so that
 413   // the first increment will point at min_point_.
 414   current_x_ = min_point_.x() - cell_size.width();
 415   current_y_ = min_point_.y();
 416   if (current_y_ <= max_point_.y())
 417     ++(*this);
 418 }
 419
 420 Picture::PixelRefIterator::~PixelRefIterator() {
 421 }
 422
 423 Picture::PixelRefIterator& Picture::PixelRefIterator::operator++() {
 424   ++current_index_;
 425   // If we're not at the end of the list, then we have the next item.
 426   if (current_index_ < current_pixel_refs_->size())
 427     return *this;
 428
 429   DCHECK(current_y_ <= max_point_.y());
 430   while (true) {
 431     gfx::Size cell_size = picture_->cell_size_;
 432
 433     // Advance the current grid cell.
 434     current_x_ += cell_size.width();
 435     if (current_x_ > max_point_.x()) {
 436       current_y_ += cell_size.height();
 437       current_x_ = min_point_.x();
 438       if (current_y_ > max_point_.y()) {
 439         current_pixel_refs_ = empty_pixel_refs_.Pointer();
 440         current_index_ = 0;
 441         break;
 442       }
 443     }
 444
 445     // If there are no pixel refs at this grid cell, keep incrementing.
 446     PixelRefMapKey key(current_x_, current_y_);
 447     PixelRefMap::const_iterator iter = picture_->pixel_refs_.find(key);
 448     if (iter == picture_->pixel_refs_.end())
 449       continue;
 450
 451     // We found a non-empty list: store it and get the first pixel ref.
 452     current_pixel_refs_ = &iter->second;
 453     current_index_ = 0;
 454     break;
 455   }
 456   return *this;
 457 }
 458
 459 scoped_refptr<base::debug::ConvertableToTraceFormat>
 460     Picture::AsTraceableRasterData(float scale) const {
 461   scoped_refptr<base::debug::TracedValue> raster_data =
 462       new base::debug::TracedValue();
 463   TracedValue::SetIDRef(this, raster_data.get(), "picture_id");
 464   raster_data->SetDouble("scale", scale);
 465   return raster_data;
 466 }
 467
 468 scoped_refptr<base::debug::ConvertableToTraceFormat>
 469     Picture::AsTraceableRecordData() const {
 470   scoped_refptr<base::debug::TracedValue> record_data =
 471       new base::debug::TracedValue();
 472   TracedValue::SetIDRef(this, record_data.get(), "picture_id");
 473   MathUtil::AddToTracedValue("layer_rect", layer_rect_, record_data.get());
 474   return record_data;
 475 }
 476
 477 }  // namespace cc