cc/output/output_surface.h

   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 #ifndef CC_OUTPUT_OUTPUT_SURFACE_H_
   6 #define CC_OUTPUT_OUTPUT_SURFACE_H_
   7
   8 #include <deque>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "cc/base/cc_export.h"
  15 #include "cc/output/context_provider.h"
  16 #include "cc/output/software_output_device.h"
  17 #include "cc/scheduler/frame_rate_controller.h"
  18 #include "cc/scheduler/rolling_time_delta_history.h"
  19
  20 namespace base { class SingleThreadTaskRunner; }
  21
  22 namespace ui { struct LatencyInfo; }
  23
  24 namespace gfx {
  25 class Rect;
  26 class Size;
  27 class Transform;
  28 }
  29
  30 namespace cc {
  31
  32 class CompositorFrame;
  33 class CompositorFrameAck;
  34 struct ManagedMemoryPolicy;
  35 class OutputSurfaceClient;
  36
  37 // Represents the output surface for a compositor. The compositor owns
  38 // and manages its destruction. Its lifetime is:
  39 //   1. Created on the main thread by the LayerTreeHost through its client.
  40 //   2. Passed to the compositor thread and bound to a client via BindToClient.
  41 //      From here on, it will only be used on the compositor thread.
  42 //   3. If the 3D context is lost, then the compositor will delete the output
  43 //      surface (on the compositor thread) and go back to step 1.
  44 class CC_EXPORT OutputSurface : public FrameRateControllerClient {
  45  public:
  46   enum {
  47     DEFAULT_MAX_FRAMES_PENDING = 2
  48   };
  49
  50   explicit OutputSurface(scoped_refptr<ContextProvider> context_provider);
  51
  52   explicit OutputSurface(scoped_ptr<SoftwareOutputDevice> software_device);
  53
  54   OutputSurface(scoped_refptr<ContextProvider> context_provider,
  55                 scoped_ptr<SoftwareOutputDevice> software_device);
  56
  57   virtual ~OutputSurface();
  58
  59   struct Capabilities {
  60     Capabilities()
  61         : delegated_rendering(false),
  62           max_frames_pending(0),
  63           deferred_gl_initialization(false),
  64           draw_and_swap_full_viewport_every_frame(false),
  65           adjust_deadline_for_parent(true),
  66           uses_default_gl_framebuffer(true) {}
  67     bool delegated_rendering;
  68     int max_frames_pending;
  69     bool deferred_gl_initialization;
  70     bool draw_and_swap_full_viewport_every_frame;
  71     // This doesn't handle the <webview> case, but once BeginImplFrame is
  72     // supported natively, we shouldn't need adjust_deadline_for_parent.
  73     bool adjust_deadline_for_parent;
  74     // Whether this output surface renders to the default OpenGL zero
  75     // framebuffer or to an offscreen framebuffer.
  76     bool uses_default_gl_framebuffer;
  77   };
  78
  79   const Capabilities& capabilities() const {
  80     return capabilities_;
  81   }
  82
  83   virtual bool HasExternalStencilTest() const;
  84
  85   // Obtain the 3d context or the software device associated with this output
  86   // surface. Either of these may return a null pointer, but not both.
  87   // In the event of a lost context, the entire output surface should be
  88   // recreated.
  89   scoped_refptr<ContextProvider> context_provider() const {
  90     return context_provider_.get();
  91   }
  92   SoftwareOutputDevice* software_device() const {
  93     return software_device_.get();
  94   }
  95
  96   // In the case where both the context3d and software_device are present
  97   // (namely Android WebView), this is called to determine whether the software
  98   // device should be used on the current frame.
  99   virtual bool ForcedDrawToSoftwareDevice() const;
 100
 101   // Called by the compositor on the compositor thread. This is a place where
 102   // thread-specific data for the output surface can be initialized, since from
 103   // this point on the output surface will only be used on the compositor
 104   // thread.
 105   virtual bool BindToClient(OutputSurfaceClient* client);
 106
 107   void InitializeBeginImplFrameEmulation(
 108       base::SingleThreadTaskRunner* task_runner,
 109       bool throttle_frame_production,
 110       base::TimeDelta interval);
 111
 112   void SetMaxFramesPending(int max_frames_pending);
 113
 114   virtual void EnsureBackbuffer();
 115   virtual void DiscardBackbuffer();
 116
 117   virtual void Reshape(gfx::Size size, float scale_factor);
 118   virtual gfx::Size SurfaceSize() const;
 119
 120   virtual void BindFramebuffer();
 121
 122   // The implementation may destroy or steal the contents of the CompositorFrame
 123   // passed in (though it will not take ownership of the CompositorFrame
 124   // itself).
 125   virtual void SwapBuffers(CompositorFrame* frame);
 126
 127   // Notifies frame-rate smoothness preference. If true, all non-critical
 128   // processing should be stopped, or lowered in priority.
 129   virtual void UpdateSmoothnessTakesPriority(bool prefer_smoothness) {}
 130
 131   // Requests a BeginImplFrame notification from the output surface. The
 132   // notification will be delivered by calling
 133   // OutputSurfaceClient::BeginImplFrame until the callback is disabled.
 134   virtual void SetNeedsBeginImplFrame(bool enable);
 135
 136   bool HasClient() { return !!client_; }
 137
 138   // Returns an estimate of the current GPU latency. When only a software
 139   // device is present, returns 0.
 140   base::TimeDelta GpuLatencyEstimate();
 141
 142  protected:
 143   // Synchronously initialize context3d and enter hardware mode.
 144   // This can only supported in threaded compositing mode.
 145   // |offscreen_context_provider| should match what is returned by
 146   // LayerTreeClient::OffscreenContextProvider().
 147   bool InitializeAndSetContext3d(
 148       scoped_refptr<ContextProvider> context_provider,
 149       scoped_refptr<ContextProvider> offscreen_context_provider);
 150   void ReleaseGL();
 151
 152   void PostSwapBuffersComplete();
 153
 154   struct OutputSurface::Capabilities capabilities_;
 155   scoped_refptr<ContextProvider> context_provider_;
 156   scoped_ptr<SoftwareOutputDevice> software_device_;
 157   gfx::Size surface_size_;
 158   float device_scale_factor_;
 159
 160   // The FrameRateController is deprecated.
 161   // Platforms should move to native BeginImplFrames instead.
 162   void OnVSyncParametersChanged(base::TimeTicks timebase,
 163                                 base::TimeDelta interval);
 164   virtual void FrameRateControllerTick(bool throttled,
 165                                        const BeginFrameArgs& args) OVERRIDE;
 166   scoped_ptr<FrameRateController> frame_rate_controller_;
 167   int max_frames_pending_;
 168   int pending_swap_buffers_;
 169   bool needs_begin_impl_frame_;
 170   bool client_ready_for_begin_impl_frame_;
 171
 172   // This stores a BeginImplFrame that we couldn't process immediately,
 173   // but might process retroactively in the near future.
 174   BeginFrameArgs skipped_begin_impl_frame_args_;
 175
 176   // Forwarded to OutputSurfaceClient but threaded through OutputSurface
 177   // first so OutputSurface has a chance to update the FrameRateController
 178   void SetNeedsRedrawRect(const gfx::Rect& damage_rect);
 179   void BeginImplFrame(const BeginFrameArgs& args);
 180   void DidSwapBuffers();
 181   void OnSwapBuffersComplete();
 182   void ReclaimResources(const CompositorFrameAck* ack);
 183   void DidLoseOutputSurface();
 184   void SetExternalStencilTest(bool enabled);
 185   void SetExternalDrawConstraints(const gfx::Transform& transform,
 186                                   const gfx::Rect& viewport,
 187                                   const gfx::Rect& clip,
 188                                   bool valid_for_tile_management);
 189
 190   // virtual for testing.
 191   virtual base::TimeTicks RetroactiveBeginImplFrameDeadline();
 192   virtual void PostCheckForRetroactiveBeginImplFrame();
 193   void CheckForRetroactiveBeginImplFrame();
 194
 195  private:
 196   OutputSurfaceClient* client_;
 197
 198   void SetUpContext3d();
 199   void ResetContext3d();
 200   void SetMemoryPolicy(const ManagedMemoryPolicy& policy);
 201   void UpdateAndMeasureGpuLatency();
 202
 203   // check_for_retroactive_begin_impl_frame_pending_ is used to avoid posting
 204   // redundant checks for a retroactive BeginImplFrame.
 205   bool check_for_retroactive_begin_impl_frame_pending_;
 206
 207   bool external_stencil_test_enabled_;
 208
 209   base::WeakPtrFactory<OutputSurface> weak_ptr_factory_;
 210
 211   std::deque<unsigned> available_gpu_latency_query_ids_;
 212   std::deque<unsigned> pending_gpu_latency_query_ids_;
 213   RollingTimeDeltaHistory gpu_latency_history_;
 214
 215   DISALLOW_COPY_AND_ASSIGN(OutputSurface);
 216 };
 217
 218 }  // namespace cc
 219
 220 #endif  // CC_OUTPUT_OUTPUT_SURFACE_H_