1 files changed, 362 insertions, 0 deletions
diff --git a/gfx/layers/client/ContentClient.h b/gfx/layers/client/ContentClient.h
new file mode 100644
index 0000000000..0763e41b3a
--- /dev/null
+++ b/gfx/layers/client/ContentClient.h
@@ -0,0 +1,362 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_CONTENTCLIENT_H
+#define MOZILLA_GFX_CONTENTCLIENT_H
+
+#include <stdint.h>         // for uint32_t
+#include "RotatedBuffer.h"  // for RotatedBuffer, etc
+#include "gfxTypes.h"
+#include "gfxPlatform.h"                        // for gfxPlatform
+#include "mozilla/Assertions.h"                 // for MOZ_CRASH
+#include "mozilla/Attributes.h"                 // for override
+#include "mozilla/RefPtr.h"                     // for RefPtr, already_AddRefed
+#include "mozilla/gfx/Point.h"                  // for IntSize
+#include "mozilla/layers/CompositableClient.h"  // for CompositableClient
+#include "mozilla/layers/CompositableForwarder.h"
+#include "mozilla/layers/CompositorTypes.h"  // for TextureInfo, etc
+#include "mozilla/layers/ISurfaceAllocator.h"
+#include "mozilla/layers/LayersSurfaces.h"  // for SurfaceDescriptor
+#include "mozilla/layers/LayersTypes.h"     // for TextureDumpMode
+#include "mozilla/layers/TextureClient.h"   // for TextureClient
+#include "mozilla/layers/PaintThread.h"     // for PaintTask
+#include "mozilla/Maybe.h"                  // for Maybe
+#include "mozilla/mozalloc.h"               // for operator delete
+#include "mozilla/UniquePtr.h"              // for UniquePtr
+#include "ReadbackProcessor.h"              // For ReadbackProcessor::Update
+#include "nsCOMPtr.h"                       // for already_AddRefed
+#include "nsPoint.h"                        // for nsIntPoint
+#include "nsRect.h"                         // for mozilla::gfx::IntRect
+#include "nsRegion.h"                       // for nsIntRegion
+#include "nsTArray.h"                       // for nsTArray
+
+namespace mozilla {
+namespace gfx {
+class DrawTarget;
+}  // namespace gfx
+
+namespace layers {
+
+class PaintedLayer;
+
+/**
+ * A compositable client for PaintedLayers. These are different to Image/Canvas
+ * clients due to sending a valid region across IPC and because we do a lot more
+ * optimisation work, encapsulated in RotatedBuffers.
+ *
+ * We use content clients for OMTC and non-OMTC, basic rendering so that
+ * BasicPaintedLayer has only one interface to deal with. We support single and
+ * double buffered flavours. For tiled layers, we do not use a ContentClient
+ * although we do have a ContentHost, and we do use texture clients and texture
+ * hosts.
+ *
+ * The interface presented by ContentClient is used by the BasicPaintedLayer
+ * methods - PaintThebes, which is the same for MT and OMTC, and PaintBuffer
+ * which is different (the OMTC one does a little more).
+ */
+class ContentClient : public CompositableClient {
+ public:
+  typedef gfxContentType ContentType;
+
+  /**
+   * Creates, configures, and returns a new content client. If necessary, a
+   * message will be sent to the compositor to create a corresponding content
+   * host.
+   */
+  static already_AddRefed<ContentClient> CreateContentClient(
+      CompositableForwarder* aFwd);
+
+  /**
+   * Controls the size of the backing buffer of this.
+   * - SizedToVisibleBounds: the backing buffer is exactly the same
+   *   size as the bounds of PaintedLayer's visible region
+   * - ContainsVisibleBounds: the backing buffer is large enough to
+   *   fit visible bounds.  May be larger.
+   */
+  enum BufferSizePolicy { SizedToVisibleBounds, ContainsVisibleBounds };
+
+  ContentClient(CompositableForwarder* aForwarder,
+                BufferSizePolicy aBufferSizePolicy)
+      : CompositableClient(aForwarder), mBufferSizePolicy(aBufferSizePolicy) {}
+
+  virtual void PrintInfo(std::stringstream& aStream, const char* aPrefix);
+
+  virtual void Clear();
+
+  /**
+   * This is returned by BeginPaint. The caller should draw into mTarget.
+   * mRegionToDraw must be drawn. mRegionToInvalidate has been invalidated
+   * by ContentClient and must be redrawn on the screen.
+   * mRegionToInvalidate is set when the buffer has changed from
+   * opaque to transparent or vice versa, since the details of rendering can
+   * depend on the buffer type.
+   */
+  struct PaintState {
+    PaintState()
+        : mRegionToDraw(),
+          mRegionToInvalidate(),
+          mMode(SurfaceMode::SURFACE_NONE),
+          mClip(DrawRegionClip::NONE),
+          mContentType(gfxContentType::SENTINEL),
+          mAsyncPaint(false),
+          mAsyncTask(nullptr) {}
+
+    nsIntRegion mRegionToDraw;
+    nsIntRegion mRegionToInvalidate;
+    SurfaceMode mMode;
+    DrawRegionClip mClip;
+    gfxContentType mContentType;
+    bool mAsyncPaint;
+    UniquePtr<PaintTask> mAsyncTask;
+  };
+
+  enum {
+    PAINT_WILL_RESAMPLE = 0x01,
+    PAINT_NO_ROTATION = 0x02,
+    PAINT_CAN_DRAW_ROTATED = 0x04,
+    PAINT_ASYNC = 0x08,
+  };
+
+  /**
+   * Start a drawing operation. This returns a PaintState describing what
+   * needs to be drawn to bring the buffer up to date in the visible region.
+   * This queries aLayer to get the currently valid and visible regions.
+   * The returned mTarget may be null if mRegionToDraw is empty.
+   * Otherwise it must not be null.
+   * mRegionToInvalidate will contain mRegionToDraw.
+   * @param aFlags when PAINT_WILL_RESAMPLE is passed, this indicates that
+   * buffer will be resampled when rendering (i.e the effective transform
+   * combined with the scale for the resolution is not just an integer
+   * translation). This will disable buffer rotation (since we don't want
+   * to resample across the rotation boundary) and will ensure that we
+   * make the entire buffer contents valid (since we don't want to sample
+   * invalid pixels outside the visible region, if the visible region doesn't
+   * fill the buffer bounds).
+   * PAINT_CAN_DRAW_ROTATED can be passed if the caller supports drawing
+   * rotated content that crosses the physical buffer boundary. The caller
+   * will need to call BorrowDrawTargetForPainting multiple times to achieve
+   * this.
+   */
+  virtual PaintState BeginPaint(PaintedLayer* aLayer, uint32_t aFlags);
+  virtual void EndPaint(
+      PaintState& aPaintState,
+      nsTArray<ReadbackProcessor::Update>* aReadbackUpdates = nullptr);
+
+  /**
+   * Fetch a DrawTarget for rendering. The DrawTarget remains owned by
+   * this. See notes on BorrowDrawTargetForQuadrantUpdate.
+   * May return null. If the return value is non-null, it must be
+   * 'un-borrowed' using ReturnDrawTarget.
+   *
+   * If PAINT_CAN_DRAW_ROTATED was specified for BeginPaint, then the caller
+   * must call this function repeatedly (with an iterator) until it returns
+   * nullptr. The caller should draw the mDrawRegion of the iterator instead
+   * of mRegionToDraw in the PaintState.
+   *
+   * @param aPaintState Paint state data returned by a call to BeginPaint
+   * @param aIter Paint state iterator. Only required if PAINT_CAN_DRAW_ROTATED
+   * was specified to BeginPaint.
+   */
+  virtual gfx::DrawTarget* BorrowDrawTargetForPainting(
+      PaintState& aPaintState, RotatedBuffer::DrawIterator* aIter = nullptr);
+
+  void ReturnDrawTarget(gfx::DrawTarget*& aReturned);
+
+  enum {
+    BUFFER_COMPONENT_ALPHA = 0x02  // Dual buffers should be created for drawing
+                                   // with component alpha.
+  };
+
+ protected:
+  struct BufferDecision {
+    nsIntRegion mNeededRegion;
+    nsIntRegion mValidRegion;
+    gfx::IntRect mBufferRect;
+    SurfaceMode mBufferMode;
+    gfxContentType mBufferContentType;
+    bool mCanReuseBuffer;
+    bool mCanKeepBufferContents;
+  };
+
+  /**
+   * Decide whether we can keep our current buffer and its contents,
+   * and return a struct containing the regions to paint, invalidate,
+   * the new buffer rect, surface mode, and content type.
+   */
+  BufferDecision CalculateBufferForPaint(PaintedLayer* aLayer, uint32_t aFlags);
+
+  static bool ValidBufferSize(BufferSizePolicy aPolicy,
+                              const gfx::IntSize& aBufferSize,
+                              const gfx::IntSize& aVisibleBoundsSize);
+
+  /**
+   * Any actions that should be performed at the last moment before we begin
+   * rendering the next frame. I.e., after we calculate what we will draw,
+   * but before we rotate the buffer and possibly create new buffers.
+   * aRegionToDraw is the region which is guaranteed to be overwritten when
+   * drawing the next frame.
+   */
+  virtual void FinalizeFrame(PaintState& aPaintState) {}
+
+  virtual RefPtr<RotatedBuffer> GetFrontBuffer() const { return mBuffer; }
+
+  /**
+   * Create a new rotated buffer for the specified content type, buffer rect,
+   * and buffer flags.
+   */
+  virtual RefPtr<RotatedBuffer> CreateBuffer(gfxContentType aType,
+                                             const gfx::IntRect& aRect,
+                                             uint32_t aFlags) = 0;
+
+  RefPtr<RotatedBuffer> mBuffer;
+  BufferSizePolicy mBufferSizePolicy;
+};
+
+// Thin wrapper around DrawTargetRotatedBuffer, for on-mtc
+class ContentClientBasic final : public ContentClient {
+ public:
+  explicit ContentClientBasic(gfx::BackendType aBackend);
+
+  void DrawTo(PaintedLayer* aLayer, gfx::DrawTarget* aTarget, float aOpacity,
+              gfx::CompositionOp aOp, gfx::SourceSurface* aMask,
+              const gfx::Matrix* aMaskTransform);
+
+  TextureInfo GetTextureInfo() const override {
+    MOZ_CRASH("GFX: Should not be called on non-remote ContentClient");
+  }
+
+ protected:
+  RefPtr<RotatedBuffer> CreateBuffer(gfxContentType aType,
+                                     const gfx::IntRect& aRect,
+                                     uint32_t aFlags) override;
+
+ private:
+  gfx::BackendType mBackend;
+};
+
+/**
+ * A ContentClient backed by a RemoteRotatedBuffer.
+ *
+ * When using a ContentClientRemoteBuffer, SurfaceDescriptors are created on
+ * the rendering side and destroyed on the compositing side. They are only
+ * passed from one side to the other when the TextureClient/Hosts are created.
+ * *Ownership* of the SurfaceDescriptor moves from the rendering side to the
+ * compositing side with the create message (send from CreateBuffer) which
+ * tells the compositor that TextureClients have been created and that the
+ * compositor should assign the corresponding TextureHosts to our corresponding
+ * ContentHost.
+ *
+ * If the size or type of our buffer(s) change(s), then we simply destroy and
+ * create them.
+ */
+class ContentClientRemoteBuffer : public ContentClient {
+ public:
+  explicit ContentClientRemoteBuffer(CompositableForwarder* aForwarder)
+      : ContentClient(aForwarder, ContainsVisibleBounds), mIsNewBuffer(false) {}
+
+  void Dump(std::stringstream& aStream, const char* aPrefix = "",
+            bool aDumpHtml = false,
+            TextureDumpMode aCompress = TextureDumpMode::Compress) override;
+
+  void EndPaint(
+      PaintState& aPaintState,
+      nsTArray<ReadbackProcessor::Update>* aReadbackUpdates = nullptr) override;
+
+  void Updated(const nsIntRegion& aRegionToDraw,
+               const nsIntRegion& aVisibleRegion);
+
+  TextureFlags ExtraTextureFlags() const {
+    return TextureFlags::IMMEDIATE_UPLOAD;
+  }
+
+ protected:
+  /**
+   * Called when we have been updated and should swap references to our
+   * buffers.
+   */
+  virtual void SwapBuffers(const nsIntRegion& aFrontUpdatedRegion) {}
+
+  virtual nsIntRegion GetUpdatedRegion(const nsIntRegion& aRegionToDraw,
+                                       const nsIntRegion& aVisibleRegion);
+
+  RefPtr<RotatedBuffer> CreateBuffer(gfxContentType aType,
+                                     const gfx::IntRect& aRect,
+                                     uint32_t aFlags) override;
+
+  RefPtr<RotatedBuffer> CreateBufferInternal(const gfx::IntRect& aRect,
+                                             gfx::SurfaceFormat aFormat,
+                                             TextureFlags aFlags);
+
+  RemoteRotatedBuffer* GetRemoteBuffer() const {
+    return static_cast<RemoteRotatedBuffer*>(mBuffer.get());
+  }
+
+  bool mIsNewBuffer;
+};
+
+/**
+ * A double buffered ContentClientRemoteBuffer. mBuffer is the back buffer,
+ * which we draw into. mFrontBuffer is the front buffer which we may read from,
+ * but not write to, when the compositor does not have the 'soft' lock.
+ *
+ * The ContentHost keeps a reference to both corresponding texture hosts, in
+ * response to our UpdateTextureRegion message, the compositor swaps its
+ * references.
+ */
+class ContentClientDoubleBuffered : public ContentClientRemoteBuffer {
+ public:
+  explicit ContentClientDoubleBuffered(CompositableForwarder* aFwd)
+      : ContentClientRemoteBuffer(aFwd), mFrontAndBackBufferDiffer(false) {}
+
+  void Dump(std::stringstream& aStream, const char* aPrefix = "",
+            bool aDumpHtml = false,
+            TextureDumpMode aCompress = TextureDumpMode::Compress) override;
+
+  void Clear() override;
+
+  void SwapBuffers(const nsIntRegion& aFrontUpdatedRegion) override;
+
+  PaintState BeginPaint(PaintedLayer* aLayer, uint32_t aFlags) override;
+
+  void FinalizeFrame(PaintState& aPaintState) override;
+
+  RefPtr<RotatedBuffer> GetFrontBuffer() const override { return mFrontBuffer; }
+
+  TextureInfo GetTextureInfo() const override {
+    return TextureInfo(CompositableType::CONTENT_DOUBLE, mTextureFlags);
+  }
+
+ private:
+  void EnsureBackBufferIfFrontBuffer();
+
+  RefPtr<RemoteRotatedBuffer> mFrontBuffer;
+  nsIntRegion mFrontUpdatedRegion;
+  bool mFrontAndBackBufferDiffer;
+};
+
+/**
+ * A single buffered ContentClientRemoteBuffer. We have a single
+ * TextureClient/Host which we update and then send a message to the
+ * compositor that we are done updating. It is not safe for the compositor
+ * to use the corresponding TextureHost's memory directly, it must upload
+ * it to video memory of some kind. We are free to modify the TextureClient
+ * once we receive reply from the compositor.
+ */
+class ContentClientSingleBuffered : public ContentClientRemoteBuffer {
+ public:
+  explicit ContentClientSingleBuffered(CompositableForwarder* aFwd)
+      : ContentClientRemoteBuffer(aFwd) {}
+
+  TextureInfo GetTextureInfo() const override {
+    return TextureInfo(CompositableType::CONTENT_SINGLE,
+                       mTextureFlags | ExtraTextureFlags());
+  }
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif