dom/canvas/SourceSurfaceWebgl.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef MOZILLA_GFX_SOURCESURFACEWEBGL_H_
   8 #define MOZILLA_GFX_SOURCESURFACEWEBGL_H_
   9
  10 #include "mozilla/gfx/2D.h"
  11 #include "mozilla/WeakPtr.h"
  12
  13 namespace mozilla::gfx {
  14
  15 class DrawTargetWebgl;
  16 class SharedContextWebgl;
  17 class TextureHandle;
  18
  19 // SourceSurfaceWebgl holds WebGL resources that can be used to efficiently
  20 // copy snapshot data between multiple DrawTargetWebgls. It also takes care
  21 // of copy-on-write behavior when the owner target is modified or destructs.
  22 class SourceSurfaceWebgl : public DataSourceSurface {
  23  public:
  24   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(SourceSurfaceWebgl, override)
  25
  26   explicit SourceSurfaceWebgl(DrawTargetWebgl* aDT);
  27   virtual ~SourceSurfaceWebgl();
  28
  29   SurfaceType GetType() const override { return SurfaceType::WEBGL; }
  30   IntSize GetSize() const override { return mSize; }
  31   SurfaceFormat GetFormat() const override { return mFormat; }
  32
  33   uint8_t* GetData() override;
  34   int32_t Stride() override;
  35
  36   bool Map(MapType aType, MappedSurface* aMappedSurface) override;
  37   void Unmap() override;
  38
  39   bool HasReadData() const { return !!mData; }
  40
  41   already_AddRefed<SourceSurface> ExtractSubrect(const IntRect& aRect) override;
  42
  43  private:
  44   friend class DrawTargetWebgl;
  45   friend class SharedContextWebgl;
  46
  47   explicit SourceSurfaceWebgl(const RefPtr<SharedContextWebgl>& aSharedContext);
  48
  49   bool EnsureData();
  50
  51   void DrawTargetWillChange(bool aNeedHandle);
  52
  53   void GiveTexture(RefPtr<TextureHandle> aHandle);
  54
  55   void SetHandle(TextureHandle* aHandle);
  56
  57   void OnUnlinkTexture(SharedContextWebgl* aContext);
  58
  59   DrawTargetWebgl* GetTarget() const { return mDT.get(); }
  60
  61   SurfaceFormat mFormat = SurfaceFormat::UNKNOWN;
  62   IntSize mSize;
  63   // Any data that has been read back from the WebGL context for mapping.
  64   RefPtr<DataSourceSurface> mData;
  65   // The draw target that currently owns the texture for this surface.
  66   WeakPtr<DrawTargetWebgl> mDT;
  67   // The actual shared context that any WebGL resources belong to.
  68   WeakPtr<SharedContextWebgl> mSharedContext;
  69   // If this snapshot has been copied into a cached texture handle.
  70   RefPtr<TextureHandle> mHandle;
  71 };
  72
  73 }  // namespace mozilla::gfx
  74
  75 #endif /* MOZILLA_GFX_SOURCESURFACEWEBGL_H_ */