cc/output/software_renderer.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/output/software_renderer.h"
   6
   7 #include "base/debug/trace_event.h"
   8 #include "cc/base/math_util.h"
   9 #include "cc/output/compositor_frame.h"
  10 #include "cc/output/compositor_frame_ack.h"
  11 #include "cc/output/compositor_frame_metadata.h"
  12 #include "cc/output/copy_output_request.h"
  13 #include "cc/output/output_surface.h"
  14 #include "cc/output/software_output_device.h"
  15 #include "cc/quads/checkerboard_draw_quad.h"
  16 #include "cc/quads/debug_border_draw_quad.h"
  17 #include "cc/quads/picture_draw_quad.h"
  18 #include "cc/quads/render_pass_draw_quad.h"
  19 #include "cc/quads/solid_color_draw_quad.h"
  20 #include "cc/quads/texture_draw_quad.h"
  21 #include "cc/quads/tile_draw_quad.h"
  22 #include "skia/ext/opacity_draw_filter.h"
  23 #include "third_party/skia/include/core/SkCanvas.h"
  24 #include "third_party/skia/include/core/SkColor.h"
  25 #include "third_party/skia/include/core/SkMatrix.h"
  26 #include "third_party/skia/include/core/SkShader.h"
  27 #include "third_party/skia/include/effects/SkLayerRasterizer.h"
  28 #include "ui/gfx/rect_conversions.h"
  29 #include "ui/gfx/skia_util.h"
  30 #include "ui/gfx/transform.h"
  31
  32 namespace cc {
  33
  34 namespace {
  35
  36 static inline bool IsScalarNearlyInteger(SkScalar scalar) {
  37   return SkScalarNearlyZero(scalar - SkScalarRound(scalar));
  38 }
  39
  40 bool IsScaleAndIntegerTranslate(const SkMatrix& matrix) {
  41   return IsScalarNearlyInteger(matrix[SkMatrix::kMTransX]) &&
  42          IsScalarNearlyInteger(matrix[SkMatrix::kMTransY]) &&
  43          SkScalarNearlyZero(matrix[SkMatrix::kMSkewX]) &&
  44          SkScalarNearlyZero(matrix[SkMatrix::kMSkewY]) &&
  45          SkScalarNearlyZero(matrix[SkMatrix::kMPersp0]) &&
  46          SkScalarNearlyZero(matrix[SkMatrix::kMPersp1]) &&
  47          SkScalarNearlyZero(matrix[SkMatrix::kMPersp2] - 1.0f);
  48 }
  49
  50 }  // anonymous namespace
  51
  52 scoped_ptr<SoftwareRenderer> SoftwareRenderer::Create(
  53     RendererClient* client,
  54     OutputSurface* output_surface,
  55     ResourceProvider* resource_provider) {
  56   return make_scoped_ptr(
  57       new SoftwareRenderer(client, output_surface, resource_provider));
  58 }
  59
  60 SoftwareRenderer::SoftwareRenderer(RendererClient* client,
  61                                    OutputSurface* output_surface,
  62                                    ResourceProvider* resource_provider)
  63   : DirectRenderer(client, output_surface, resource_provider),
  64     visible_(true),
  65     is_scissor_enabled_(false),
  66     is_backbuffer_discarded_(false),
  67     output_device_(output_surface->software_device()),
  68     current_canvas_(NULL) {
  69   if (resource_provider_) {
  70     capabilities_.max_texture_size = resource_provider_->max_texture_size();
  71     capabilities_.best_texture_format =
  72         resource_provider_->best_texture_format();
  73   }
  74   capabilities_.using_set_visibility = true;
  75   // The updater can access bitmaps while the SoftwareRenderer is using them.
  76   capabilities_.allow_partial_texture_updates = true;
  77   capabilities_.using_partial_swap = true;
  78
  79   capabilities_.using_map_image = Settings().use_map_image;
  80   capabilities_.using_shared_memory_resources = true;
  81 }
  82
  83 SoftwareRenderer::~SoftwareRenderer() {}
  84
  85 const RendererCapabilities& SoftwareRenderer::Capabilities() const {
  86   return capabilities_;
  87 }
  88
  89 void SoftwareRenderer::BeginDrawingFrame(DrawingFrame* frame) {
  90   TRACE_EVENT0("cc", "SoftwareRenderer::BeginDrawingFrame");
  91   root_canvas_ = output_device_->BeginPaint(
  92       gfx::ToEnclosingRect(frame->root_damage_rect));
  93 }
  94
  95 void SoftwareRenderer::FinishDrawingFrame(DrawingFrame* frame) {
  96   TRACE_EVENT0("cc", "SoftwareRenderer::FinishDrawingFrame");
  97   current_framebuffer_lock_.reset();
  98   current_canvas_ = NULL;
  99   root_canvas_ = NULL;
 100
 101   current_frame_data_.reset(new SoftwareFrameData);
 102   output_device_->EndPaint(current_frame_data_.get());
 103 }
 104
 105 void SoftwareRenderer::SwapBuffers() {
 106   CompositorFrame compositor_frame;
 107   compositor_frame.metadata = client_->MakeCompositorFrameMetadata();
 108   compositor_frame.software_frame_data = current_frame_data_.Pass();
 109   output_surface_->SwapBuffers(&compositor_frame);
 110 }
 111
 112 void SoftwareRenderer::ReceiveSwapBuffersAck(const CompositorFrameAck& ack) {
 113   output_device_->ReclaimSoftwareFrame(ack.last_software_frame_id);
 114 }
 115
 116 bool SoftwareRenderer::FlippedFramebuffer() const {
 117   return false;
 118 }
 119
 120 void SoftwareRenderer::EnsureScissorTestEnabled() {
 121   is_scissor_enabled_ = true;
 122   SetClipRect(scissor_rect_);
 123 }
 124
 125 void SoftwareRenderer::EnsureScissorTestDisabled() {
 126   // There is no explicit notion of enabling/disabling scissoring in software
 127   // rendering, but the underlying effect we want is to clear any existing
 128   // clipRect on the current SkCanvas. This is done by setting clipRect to
 129   // the viewport's dimensions.
 130   is_scissor_enabled_ = false;
 131   SkBaseDevice* device = current_canvas_->getDevice();
 132   SetClipRect(gfx::Rect(device->width(), device->height()));
 133 }
 134
 135 void SoftwareRenderer::Finish() {}
 136
 137 void SoftwareRenderer::BindFramebufferToOutputSurface(DrawingFrame* frame) {
 138   DCHECK(!client_->ExternalStencilTestEnabled());
 139   current_framebuffer_lock_.reset();
 140   current_canvas_ = root_canvas_;
 141 }
 142
 143 bool SoftwareRenderer::BindFramebufferToTexture(
 144     DrawingFrame* frame,
 145     const ScopedResource* texture,
 146     gfx::Rect target_rect) {
 147   current_framebuffer_lock_.reset();
 148   current_framebuffer_lock_ = make_scoped_ptr(
 149       new ResourceProvider::ScopedWriteLockSoftware(
 150           resource_provider_, texture->id()));
 151   current_canvas_ = current_framebuffer_lock_->sk_canvas();
 152   InitializeViewport(frame,
 153                      target_rect,
 154                      gfx::Rect(target_rect.size()),
 155                      target_rect.size());
 156   return true;
 157 }
 158
 159 void SoftwareRenderer::SetScissorTestRect(gfx::Rect scissor_rect) {
 160   is_scissor_enabled_ = true;
 161   scissor_rect_ = scissor_rect;
 162   SetClipRect(scissor_rect);
 163 }
 164
 165 void SoftwareRenderer::SetClipRect(gfx::Rect rect) {
 166   // Skia applies the current matrix to clip rects so we reset it temporary.
 167   SkMatrix current_matrix = current_canvas_->getTotalMatrix();
 168   current_canvas_->resetMatrix();
 169   current_canvas_->clipRect(gfx::RectToSkRect(rect), SkRegion::kReplace_Op);
 170   current_canvas_->setMatrix(current_matrix);
 171 }
 172
 173 void SoftwareRenderer::ClearCanvas(SkColor color) {
 174   // SkCanvas::clear doesn't respect the current clipping region
 175   // so we SkCanvas::drawColor instead if scissoring is active.
 176   if (is_scissor_enabled_)
 177     current_canvas_->drawColor(color, SkXfermode::kSrc_Mode);
 178   else
 179     current_canvas_->clear(color);
 180 }
 181
 182 void SoftwareRenderer::ClearFramebuffer(DrawingFrame* frame) {
 183   if (frame->current_render_pass->has_transparent_background) {
 184     ClearCanvas(SkColorSetARGB(0, 0, 0, 0));
 185   } else {
 186 #ifndef NDEBUG
 187     // On DEBUG builds, opaque render passes are cleared to blue
 188     // to easily see regions that were not drawn on the screen.
 189     ClearCanvas(SkColorSetARGB(255, 0, 0, 255));
 190 #endif
 191   }
 192 }
 193
 194 void SoftwareRenderer::SetDrawViewport(gfx::Rect window_space_viewport) {}
 195
 196 bool SoftwareRenderer::IsSoftwareResource(
 197     ResourceProvider::ResourceId resource_id) const {
 198   switch (resource_provider_->GetResourceType(resource_id)) {
 199     case ResourceProvider::GLTexture:
 200       return false;
 201     case ResourceProvider::Bitmap:
 202       return true;
 203     case ResourceProvider::InvalidType:
 204       break;
 205   }
 206
 207   LOG(FATAL) << "Invalid resource type.";
 208   return false;
 209 }
 210
 211 void SoftwareRenderer::DoDrawQuad(DrawingFrame* frame, const DrawQuad* quad) {
 212   TRACE_EVENT0("cc", "SoftwareRenderer::DoDrawQuad");
 213   gfx::Transform quad_rect_matrix;
 214   QuadRectTransform(&quad_rect_matrix, quad->quadTransform(), quad->rect);
 215   gfx::Transform contents_device_transform =
 216       frame->window_matrix * frame->projection_matrix * quad_rect_matrix;
 217   contents_device_transform.FlattenTo2d();
 218   SkMatrix sk_device_matrix;
 219   gfx::TransformToFlattenedSkMatrix(contents_device_transform,
 220                                     &sk_device_matrix);
 221   current_canvas_->setMatrix(sk_device_matrix);
 222
 223   current_paint_.reset();
 224   if (!IsScaleAndIntegerTranslate(sk_device_matrix)) {
 225     // TODO(danakj): Until we can enable AA only on exterior edges of the
 226     // layer, disable AA if any interior edges are present. crbug.com/248175
 227     bool all_four_edges_are_exterior = quad->IsTopEdge() &&
 228                                        quad->IsLeftEdge() &&
 229                                        quad->IsBottomEdge() &&
 230                                        quad->IsRightEdge();
 231     if (Settings().allow_antialiasing &&
 232         all_four_edges_are_exterior)
 233       current_paint_.setAntiAlias(true);
 234     current_paint_.setFilterBitmap(true);
 235   }
 236
 237   if (quad->ShouldDrawWithBlending()) {
 238     current_paint_.setAlpha(quad->opacity() * 255);
 239     current_paint_.setXfermodeMode(SkXfermode::kSrcOver_Mode);
 240   } else {
 241     current_paint_.setXfermodeMode(SkXfermode::kSrc_Mode);
 242   }
 243
 244   switch (quad->material) {
 245     case DrawQuad::CHECKERBOARD:
 246       DrawCheckerboardQuad(frame, CheckerboardDrawQuad::MaterialCast(quad));
 247       break;
 248     case DrawQuad::DEBUG_BORDER:
 249       DrawDebugBorderQuad(frame, DebugBorderDrawQuad::MaterialCast(quad));
 250       break;
 251     case DrawQuad::PICTURE_CONTENT:
 252       DrawPictureQuad(frame, PictureDrawQuad::MaterialCast(quad));
 253       break;
 254     case DrawQuad::RENDER_PASS:
 255       DrawRenderPassQuad(frame, RenderPassDrawQuad::MaterialCast(quad));
 256       break;
 257     case DrawQuad::SOLID_COLOR:
 258       DrawSolidColorQuad(frame, SolidColorDrawQuad::MaterialCast(quad));
 259       break;
 260     case DrawQuad::TEXTURE_CONTENT:
 261       DrawTextureQuad(frame, TextureDrawQuad::MaterialCast(quad));
 262       break;
 263     case DrawQuad::TILED_CONTENT:
 264       DrawTileQuad(frame, TileDrawQuad::MaterialCast(quad));
 265       break;
 266     case DrawQuad::INVALID:
 267     case DrawQuad::IO_SURFACE_CONTENT:
 268     case DrawQuad::YUV_VIDEO_CONTENT:
 269     case DrawQuad::STREAM_VIDEO_CONTENT:
 270       DrawUnsupportedQuad(frame, quad);
 271       NOTREACHED();
 272       break;
 273   }
 274
 275   current_canvas_->resetMatrix();
 276 }
 277
 278 void SoftwareRenderer::DrawCheckerboardQuad(const DrawingFrame* frame,
 279                                             const CheckerboardDrawQuad* quad) {
 280   gfx::RectF visible_quad_vertex_rect = MathUtil::ScaleRectProportional(
 281       QuadVertexRect(), quad->rect, quad->visible_rect);
 282   current_paint_.setColor(quad->color);
 283   current_paint_.setAlpha(quad->opacity() * SkColorGetA(quad->color));
 284   current_canvas_->drawRect(gfx::RectFToSkRect(visible_quad_vertex_rect),
 285                             current_paint_);
 286 }
 287
 288 void SoftwareRenderer::DrawDebugBorderQuad(const DrawingFrame* frame,
 289                                            const DebugBorderDrawQuad* quad) {
 290   // We need to apply the matrix manually to have pixel-sized stroke width.
 291   SkPoint vertices[4];
 292   gfx::RectFToSkRect(QuadVertexRect()).toQuad(vertices);
 293   SkPoint transformed_vertices[4];
 294   current_canvas_->getTotalMatrix().mapPoints(transformed_vertices,
 295                                               vertices,
 296                                               4);
 297   current_canvas_->resetMatrix();
 298
 299   current_paint_.setColor(quad->color);
 300   current_paint_.setAlpha(quad->opacity() * SkColorGetA(quad->color));
 301   current_paint_.setStyle(SkPaint::kStroke_Style);
 302   current_paint_.setStrokeWidth(quad->width);
 303   current_canvas_->drawPoints(SkCanvas::kPolygon_PointMode,
 304                               4, transformed_vertices, current_paint_);
 305 }
 306
 307 void SoftwareRenderer::DrawPictureQuad(const DrawingFrame* frame,
 308                                        const PictureDrawQuad* quad) {
 309   SkMatrix content_matrix;
 310   content_matrix.setRectToRect(
 311       gfx::RectFToSkRect(quad->tex_coord_rect),
 312       gfx::RectFToSkRect(QuadVertexRect()),
 313       SkMatrix::kFill_ScaleToFit);
 314   current_canvas_->concat(content_matrix);
 315
 316   // TODO(aelias): This isn't correct in all cases. We should detect these
 317   // cases and fall back to a persistent bitmap backing
 318   // (http://crbug.com/280374).
 319   DCHECK(!current_canvas_->getDrawFilter());
 320   current_canvas_->setDrawFilter(new skia::OpacityDrawFilter(quad->opacity(),
 321                                                              true));
 322
 323   TRACE_EVENT0("cc",
 324                "SoftwareRenderer::DrawPictureQuad");
 325   quad->picture_pile->RasterDirect(
 326       current_canvas_, quad->content_rect, quad->contents_scale, NULL);
 327
 328   current_canvas_->setDrawFilter(NULL);
 329 }
 330
 331 void SoftwareRenderer::DrawSolidColorQuad(const DrawingFrame* frame,
 332                                           const SolidColorDrawQuad* quad) {
 333   gfx::RectF visible_quad_vertex_rect = MathUtil::ScaleRectProportional(
 334       QuadVertexRect(), quad->rect, quad->visible_rect);
 335   current_paint_.setColor(quad->color);
 336   current_paint_.setAlpha(quad->opacity() * SkColorGetA(quad->color));
 337   current_canvas_->drawRect(gfx::RectFToSkRect(visible_quad_vertex_rect),
 338                             current_paint_);
 339 }
 340
 341 void SoftwareRenderer::DrawTextureQuad(const DrawingFrame* frame,
 342                                        const TextureDrawQuad* quad) {
 343   if (!IsSoftwareResource(quad->resource_id)) {
 344     DrawUnsupportedQuad(frame, quad);
 345     return;
 346   }
 347
 348   // TODO(skaslev): Add support for non-premultiplied alpha.
 349   ResourceProvider::ScopedReadLockSoftware lock(resource_provider_,
 350                                                 quad->resource_id);
 351   const SkBitmap* bitmap = lock.sk_bitmap();
 352   gfx::RectF uv_rect = gfx::ScaleRect(gfx::BoundingRect(quad->uv_top_left,
 353                                                         quad->uv_bottom_right),
 354                                       bitmap->width(),
 355                                       bitmap->height());
 356   gfx::RectF visible_uv_rect =
 357       MathUtil::ScaleRectProportional(uv_rect, quad->rect, quad->visible_rect);
 358   SkRect sk_uv_rect = gfx::RectFToSkRect(visible_uv_rect);
 359   gfx::RectF visible_quad_vertex_rect = MathUtil::ScaleRectProportional(
 360       QuadVertexRect(), quad->rect, quad->visible_rect);
 361   SkRect quad_rect = gfx::RectFToSkRect(visible_quad_vertex_rect);
 362
 363   if (quad->flipped)
 364     current_canvas_->scale(1, -1);
 365
 366   bool blend_background = quad->background_color != SK_ColorTRANSPARENT &&
 367                           !bitmap->isOpaque();
 368   bool needs_layer = blend_background && (current_paint_.getAlpha() != 0xFF);
 369   if (needs_layer) {
 370     current_canvas_->saveLayerAlpha(&quad_rect, current_paint_.getAlpha());
 371     current_paint_.setAlpha(0xFF);
 372   }
 373   if (blend_background) {
 374     SkPaint background_paint;
 375     background_paint.setColor(quad->background_color);
 376     current_canvas_->drawRect(quad_rect, background_paint);
 377   }
 378
 379   current_canvas_->drawBitmapRectToRect(*bitmap,
 380                                         &sk_uv_rect,
 381                                         quad_rect,
 382                                         &current_paint_);
 383
 384   if (needs_layer)
 385     current_canvas_->restore();
 386 }
 387
 388 void SoftwareRenderer::DrawTileQuad(const DrawingFrame* frame,
 389                                     const TileDrawQuad* quad) {
 390   DCHECK(!output_surface_->ForcedDrawToSoftwareDevice());
 391   DCHECK(IsSoftwareResource(quad->resource_id));
 392   ResourceProvider::ScopedReadLockSoftware lock(resource_provider_,
 393                                                 quad->resource_id);
 394   gfx::RectF visible_tex_coord_rect = MathUtil::ScaleRectProportional(
 395       quad->tex_coord_rect, quad->rect, quad->visible_rect);
 396   gfx::RectF visible_quad_vertex_rect = MathUtil::ScaleRectProportional(
 397       QuadVertexRect(), quad->rect, quad->visible_rect);
 398
 399   SkRect uv_rect = gfx::RectFToSkRect(visible_tex_coord_rect);
 400   current_paint_.setFilterBitmap(true);
 401   current_canvas_->drawBitmapRectToRect(
 402       *lock.sk_bitmap(),
 403       &uv_rect,
 404       gfx::RectFToSkRect(visible_quad_vertex_rect),
 405       &current_paint_);
 406 }
 407
 408 void SoftwareRenderer::DrawRenderPassQuad(const DrawingFrame* frame,
 409                                           const RenderPassDrawQuad* quad) {
 410   CachedResource* content_texture =
 411       render_pass_textures_.get(quad->render_pass_id);
 412   if (!content_texture || !content_texture->id())
 413     return;
 414
 415   DCHECK(IsSoftwareResource(content_texture->id()));
 416   ResourceProvider::ScopedReadLockSoftware lock(resource_provider_,
 417                                                 content_texture->id());
 418
 419   SkRect dest_rect = gfx::RectFToSkRect(QuadVertexRect());
 420   SkRect dest_visible_rect = gfx::RectFToSkRect(MathUtil::ScaleRectProportional(
 421       QuadVertexRect(), quad->rect, quad->visible_rect));
 422   SkRect content_rect = SkRect::MakeWH(quad->rect.width(), quad->rect.height());
 423
 424   SkMatrix content_mat;
 425   content_mat.setRectToRect(content_rect, dest_rect,
 426                             SkMatrix::kFill_ScaleToFit);
 427
 428   const SkBitmap* content = lock.sk_bitmap();
 429   skia::RefPtr<SkShader> shader = skia::AdoptRef(
 430       SkShader::CreateBitmapShader(*content,
 431                                    SkShader::kClamp_TileMode,
 432                                    SkShader::kClamp_TileMode));
 433   shader->setLocalMatrix(content_mat);
 434   current_paint_.setShader(shader.get());
 435
 436   SkImageFilter* filter = quad->filter.get();
 437   if (filter)
 438     current_paint_.setImageFilter(filter);
 439
 440   if (quad->mask_resource_id) {
 441     ResourceProvider::ScopedReadLockSoftware mask_lock(resource_provider_,
 442                                                        quad->mask_resource_id);
 443
 444     const SkBitmap* mask = mask_lock.sk_bitmap();
 445
 446     SkRect mask_rect = SkRect::MakeXYWH(
 447         quad->mask_uv_rect.x() * mask->width(),
 448         quad->mask_uv_rect.y() * mask->height(),
 449         quad->mask_uv_rect.width() * mask->width(),
 450         quad->mask_uv_rect.height() * mask->height());
 451
 452     SkMatrix mask_mat;
 453     mask_mat.setRectToRect(mask_rect, dest_rect, SkMatrix::kFill_ScaleToFit);
 454
 455     skia::RefPtr<SkShader> mask_shader = skia::AdoptRef(
 456         SkShader::CreateBitmapShader(*mask,
 457                                      SkShader::kClamp_TileMode,
 458                                      SkShader::kClamp_TileMode));
 459     mask_shader->setLocalMatrix(mask_mat);
 460
 461     SkPaint mask_paint;
 462     mask_paint.setShader(mask_shader.get());
 463
 464     skia::RefPtr<SkLayerRasterizer> mask_rasterizer =
 465         skia::AdoptRef(new SkLayerRasterizer);
 466     mask_rasterizer->addLayer(mask_paint);
 467
 468     current_paint_.setRasterizer(mask_rasterizer.get());
 469     current_canvas_->drawRect(dest_visible_rect, current_paint_);
 470   } else {
 471     // TODO(skaslev): Apply background filters and blend with content
 472     current_canvas_->drawRect(dest_visible_rect, current_paint_);
 473   }
 474 }
 475
 476 void SoftwareRenderer::DrawUnsupportedQuad(const DrawingFrame* frame,
 477                                            const DrawQuad* quad) {
 478 #ifdef NDEBUG
 479   current_paint_.setColor(SK_ColorWHITE);
 480 #else
 481   current_paint_.setColor(SK_ColorMAGENTA);
 482 #endif
 483   current_paint_.setAlpha(quad->opacity() * 255);
 484   current_canvas_->drawRect(gfx::RectFToSkRect(QuadVertexRect()),
 485                             current_paint_);
 486 }
 487
 488 void SoftwareRenderer::CopyCurrentRenderPassToBitmap(
 489     DrawingFrame* frame,
 490     scoped_ptr<CopyOutputRequest> request) {
 491   gfx::Rect copy_rect = frame->current_render_pass->output_rect;
 492   if (request->has_area()) {
 493     // Intersect with the request's area, positioned with its origin at the
 494     // origin of the full copy_rect.
 495     copy_rect.Intersect(request->area() - copy_rect.OffsetFromOrigin());
 496   }
 497   gfx::Rect window_copy_rect = MoveFromDrawToWindowSpace(copy_rect);
 498
 499   scoped_ptr<SkBitmap> bitmap(new SkBitmap);
 500   bitmap->setConfig(SkBitmap::kARGB_8888_Config,
 501                     window_copy_rect.width(),
 502                     window_copy_rect.height());
 503   current_canvas_->readPixels(
 504       bitmap.get(), window_copy_rect.x(), window_copy_rect.y());
 505
 506   request->SendBitmapResult(bitmap.Pass());
 507 }
 508
 509 void SoftwareRenderer::DiscardBackbuffer() {
 510   if (is_backbuffer_discarded_)
 511     return;
 512
 513   output_surface_->DiscardBackbuffer();
 514
 515   is_backbuffer_discarded_ = true;
 516
 517   // Damage tracker needs a full reset every time framebuffer is discarded.
 518   client_->SetFullRootLayerDamage();
 519 }
 520
 521 void SoftwareRenderer::EnsureBackbuffer() {
 522   if (!is_backbuffer_discarded_)
 523     return;
 524
 525   output_surface_->EnsureBackbuffer();
 526   is_backbuffer_discarded_ = false;
 527 }
 528
 529 void SoftwareRenderer::GetFramebufferPixels(void* pixels, gfx::Rect rect) {
 530   TRACE_EVENT0("cc", "SoftwareRenderer::GetFramebufferPixels");
 531   SkBitmap subset_bitmap;
 532   rect += current_viewport_rect_.OffsetFromOrigin();
 533   output_device_->CopyToBitmap(rect, &subset_bitmap);
 534   subset_bitmap.copyPixelsTo(pixels,
 535                              4 * rect.width() * rect.height(),
 536                              4 * rect.width());
 537 }
 538
 539 void SoftwareRenderer::SetVisible(bool visible) {
 540   if (visible_ == visible)
 541     return;
 542   visible_ = visible;
 543
 544   if (visible_)
 545     EnsureBackbuffer();
 546   else
 547     DiscardBackbuffer();
 548 }
 549
 550 void SoftwareRenderer::SetDiscardBackBufferWhenNotVisible(bool discard) {
 551   // The software renderer always discards the backbuffer when not visible.
 552 }
 553
 554 }  // namespace cc