cc/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 "base/debug/trace_event.h"
   6 #include "cc/content_layer_client.h"
   7 #include "cc/picture.h"
   8 #include "cc/rendering_stats.h"
   9 #include "skia/ext/analysis_canvas.h"
  10 #include "third_party/skia/include/core/SkCanvas.h"
  11 #include "third_party/skia/include/core/SkData.h"
  12 #include "third_party/skia/include/core/SkTileGridPicture.h"
  13 #include "third_party/skia/include/utils/SkPictureUtils.h"
  14 #include "ui/gfx/rect_conversions.h"
  15 #include "ui/gfx/skia_util.h"
  16
  17 namespace {
  18 // URI label for a lazily decoded SkPixelRef.
  19 const char labelLazyDecoded[] = "lazy";
  20 // Tile size in recording coordinates used by SkTileGridPicture
  21 const int tileGridSize = 256;
  22 }
  23
  24 namespace cc {
  25
  26 scoped_refptr<Picture> Picture::Create(gfx::Rect layer_rect) {
  27   return make_scoped_refptr(new Picture(layer_rect));
  28 }
  29
  30 Picture::Picture(gfx::Rect layer_rect)
  31     : layer_rect_(layer_rect) {
  32 }
  33
  34 Picture::Picture(const skia::RefPtr<SkPicture>& picture,
  35                  gfx::Rect layer_rect,
  36                  gfx::Rect opaque_rect) :
  37     layer_rect_(layer_rect),
  38     opaque_rect_(opaque_rect),
  39     picture_(picture) {
  40 }
  41
  42 Picture::~Picture() {
  43 }
  44
  45 scoped_refptr<Picture> Picture::Clone() const {
  46   // SkPicture is not thread-safe to rasterize with, so return a thread-safe
  47   // clone of it.
  48   DCHECK(picture_);
  49   skia::RefPtr<SkPicture> clone = skia::AdoptRef(picture_->clone());
  50   return make_scoped_refptr(new Picture(clone, layer_rect_, opaque_rect_));
  51 }
  52
  53 void Picture::Record(ContentLayerClient* painter,
  54                      RenderingStats* stats) {
  55   TRACE_EVENT2("cc", "Picture::Record",
  56                "width", layer_rect_.width(), "height", layer_rect_.height());
  57
  58   // Record() should only be called once.
  59   DCHECK(!picture_);
  60   picture_ = skia::AdoptRef(new SkTileGridPicture(
  61       tileGridSize, tileGridSize, layer_rect_.width(), layer_rect_.height()));
  62
  63   SkCanvas* canvas = picture_->beginRecording(
  64       layer_rect_.width(),
  65       layer_rect_.height(),
  66       SkPicture::kUsePathBoundsForClip_RecordingFlag |
  67       SkPicture::kOptimizeForClippedPlayback_RecordingFlag);
  68
  69   canvas->save();
  70   canvas->translate(SkFloatToScalar(-layer_rect_.x()),
  71                     SkFloatToScalar(-layer_rect_.y()));
  72
  73   SkPaint paint;
  74   paint.setAntiAlias(false);
  75   paint.setXfermodeMode(SkXfermode::kClear_Mode);
  76   SkRect layer_skrect = SkRect::MakeXYWH(layer_rect_.x(),
  77                                          layer_rect_.y(),
  78                                          layer_rect_.width(),
  79                                          layer_rect_.height());
  80   canvas->clipRect(layer_skrect);
  81   canvas->drawRect(layer_skrect, paint);
  82
  83   gfx::RectF opaque_layer_rect;
  84   base::TimeTicks begin_paint_time;
  85   if (stats)
  86     begin_paint_time = base::TimeTicks::Now();
  87   painter->paintContents(canvas, layer_rect_, opaque_layer_rect);
  88   if (stats) {
  89     stats->totalPaintTime += base::TimeTicks::Now() - begin_paint_time;
  90     stats->totalPixelsPainted +=
  91         layer_rect_.width() * layer_rect_.height();
  92   }
  93
  94   canvas->restore();
  95   picture_->endRecording();
  96
  97   opaque_rect_ = gfx::ToEnclosedRect(opaque_layer_rect);
  98 }
  99
 100 void Picture::Raster(
 101     SkCanvas* canvas,
 102     gfx::Rect content_rect,
 103     float contents_scale) {
 104   TRACE_EVENT2("cc", "Picture::Raster",
 105                "layer width", layer_rect_.width(),
 106                "layer height", layer_rect_.height());
 107   DCHECK(picture_);
 108
 109   canvas->save();
 110   canvas->clipRect(gfx::RectToSkRect(content_rect));
 111   canvas->scale(contents_scale, contents_scale);
 112   canvas->translate(layer_rect_.x(), layer_rect_.y());
 113   canvas->drawPicture(*picture_);
 114   canvas->restore();
 115 }
 116
 117 bool Picture::IsCheapInRect(const gfx::Rect& layer_rect) const {
 118   TRACE_EVENT0("cc", "Picture::IsCheapInRect");
 119
 120   SkBitmap emptyBitmap;
 121   emptyBitmap.setConfig(SkBitmap::kNo_Config, layer_rect.width(),
 122                         layer_rect.height());
 123   skia::AnalysisDevice device(emptyBitmap);
 124   skia::AnalysisCanvas canvas(&device);
 125
 126   canvas.drawPicture(*picture_);
 127   return canvas.isCheap();
 128 }
 129
 130 void Picture::GatherPixelRefs(const gfx::Rect& layer_rect,
 131                               std::list<skia::LazyPixelRef*>& pixel_ref_list) {
 132   DCHECK(picture_);
 133   SkData* pixel_refs = SkPictureUtils::GatherPixelRefs(
 134       picture_.get(), SkRect::MakeXYWH(layer_rect.x(),
 135                                        layer_rect.y(),
 136                                        layer_rect.width(),
 137                                        layer_rect.height()));
 138   if (!pixel_refs)
 139     return;
 140
 141   void* data = const_cast<void*>(pixel_refs->data());
 142   if (!data) {
 143     pixel_refs->unref();
 144     return;
 145   }
 146
 147   SkPixelRef** refs = reinterpret_cast<SkPixelRef**>(data);
 148   for (unsigned int i = 0; i < pixel_refs->size() / sizeof(SkPixelRef*); ++i) {
 149     if (*refs && (*refs)->getURI() && !strncmp(
 150         (*refs)->getURI(), labelLazyDecoded, 4)) {
 151       pixel_ref_list.push_back(static_cast<skia::LazyPixelRef*>(*refs));
 152     }
 153     refs++;
 154   }
 155   pixel_refs->unref();
 156 }
 157
 158 }  // namespace cc