| /* |
| * Copyright 2008 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkPixelRef_DEFINED |
| #define SkPixelRef_DEFINED |
| |
| #include "../private/SkAtomics.h" |
| #include "../private/SkMutex.h" |
| #include "../private/SkTDArray.h" |
| #include "SkBitmap.h" |
| #include "SkFilterQuality.h" |
| #include "SkImageInfo.h" |
| #include "SkPixmap.h" |
| #include "SkRefCnt.h" |
| #include "SkSize.h" |
| #include "SkString.h" |
| |
| struct SkIRect; |
| |
| class GrTexture; |
| class SkDiscardableMemory; |
| |
| /** \class SkPixelRef |
| |
| This class is the smart container for pixel memory, and is used with SkBitmap. |
| This class can be shared/accessed between multiple threads. |
| */ |
| class SK_API SkPixelRef : public SkRefCnt { |
| public: |
| SkPixelRef(int width, int height, void* addr, size_t rowBytes); |
| ~SkPixelRef() override; |
| |
| int width() const { return fWidth; } |
| int height() const { return fHeight; } |
| void* pixels() const { return fPixels; } |
| size_t rowBytes() const { return fRowBytes; } |
| |
| /** Returns a non-zero, unique value corresponding to the pixels in this |
| pixelref. Each time the pixels are changed (and notifyPixelsChanged is |
| called), a different generation ID will be returned. |
| */ |
| uint32_t getGenerationID() const; |
| |
| #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK |
| /** Returns a non-zero, unique value corresponding to this SkPixelRef. |
| Unlike the generation ID, this ID remains the same even when the pixels |
| are changed. IDs are not reused (until uint32_t wraps), so it is safe |
| to consider this ID unique even after this SkPixelRef is deleted. |
| |
| Can be used as a key which uniquely identifies this SkPixelRef |
| regardless of changes to its pixels or deletion of this object. |
| */ |
| uint32_t getStableID() const { return fStableID; } |
| #endif |
| |
| /** |
| * Call this if you have changed the contents of the pixels. This will in- |
| * turn cause a different generation ID value to be returned from |
| * getGenerationID(). |
| */ |
| void notifyPixelsChanged(); |
| |
| /** Returns true if this pixelref is marked as immutable, meaning that the |
| contents of its pixels will not change for the lifetime of the pixelref. |
| */ |
| bool isImmutable() const { return fMutability != kMutable; } |
| |
| /** Marks this pixelref is immutable, meaning that the contents of its |
| pixels will not change for the lifetime of the pixelref. This state can |
| be set on a pixelref, but it cannot be cleared once it is set. |
| */ |
| void setImmutable(); |
| |
| // Register a listener that may be called the next time our generation ID changes. |
| // |
| // We'll only call the listener if we're confident that we are the only SkPixelRef with this |
| // generation ID. If our generation ID changes and we decide not to call the listener, we'll |
| // never call it: you must add a new listener for each generation ID change. We also won't call |
| // the listener when we're certain no one knows what our generation ID is. |
| // |
| // This can be used to invalidate caches keyed by SkPixelRef generation ID. |
| struct GenIDChangeListener { |
| virtual ~GenIDChangeListener() {} |
| virtual void onChange() = 0; |
| }; |
| |
| // Takes ownership of listener. |
| void addGenIDChangeListener(GenIDChangeListener* listener); |
| |
| // Call when this pixelref is part of the key to a resourcecache entry. This allows the cache |
| // to know automatically those entries can be purged when this pixelref is changed or deleted. |
| void notifyAddedToCache() { |
| fAddedToCache.store(true); |
| } |
| |
| virtual SkDiscardableMemory* diagnostic_only_getDiscardable() const { return nullptr; } |
| |
| protected: |
| // default impl does nothing. |
| virtual void onNotifyPixelsChanged(); |
| |
| void android_only_reset(int width, int height, size_t rowBytes); |
| |
| private: |
| int fWidth; |
| int fHeight; |
| void* fPixels; |
| size_t fRowBytes; |
| |
| // Bottom bit indicates the Gen ID is unique. |
| bool genIDIsUnique() const { return SkToBool(fTaggedGenID.load() & 1); } |
| mutable SkAtomic<uint32_t> fTaggedGenID; |
| |
| #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK |
| const uint32_t fStableID; |
| #endif |
| |
| SkTDArray<GenIDChangeListener*> fGenIDChangeListeners; // pointers are owned |
| |
| // Set true by caches when they cache content that's derived from the current pixels. |
| SkAtomic<bool> fAddedToCache; |
| |
| enum { |
| kMutable, // PixelRefs begin mutable. |
| kTemporarilyImmutable, // Considered immutable, but can revert to mutable. |
| kImmutable, // Once set to this state, it never leaves. |
| } fMutability : 8; // easily fits inside a byte |
| |
| void needsNewGenID(); |
| void callGenIDChangeListeners(); |
| |
| void setTemporarilyImmutable(); |
| void restoreMutability(); |
| friend class SkSurface_Raster; // For the two methods above. |
| |
| friend class SkImage_Raster; |
| friend class SkSpecialImage_Raster; |
| |
| void setImmutableWithID(uint32_t genID); |
| friend class SkImage_Gpu; |
| friend class SkImage_Lazy; |
| friend class SkSpecialImage_Gpu; |
| friend void SkBitmapCache_setImmutableWithID(SkPixelRef*, uint32_t); |
| |
| typedef SkRefCnt INHERITED; |
| }; |
| |
| #endif |