| /* |
| * 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 "include/core/SkBitmap.h" |
| #include "include/core/SkImageInfo.h" |
| #include "include/core/SkPixmap.h" |
| #include "include/core/SkRefCnt.h" |
| #include "include/core/SkSize.h" |
| #include "include/private/SkIDChangeListener.h" |
| #include "include/private/SkTDArray.h" |
| #include "include/private/base/SkMutex.h" |
| |
| #include <atomic> |
| |
| 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; |
| |
| SkISize dimensions() const { return {fWidth, fHeight}; } |
| 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; |
| |
| /** |
| * 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. |
| // Takes ownership of listener. Threadsafe. |
| void addGenIDChangeListener(sk_sp<SkIDChangeListener> 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: |
| 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 std::atomic<uint32_t> fTaggedGenID; |
| |
| SkIDChangeListener::List fGenIDChangeListeners; |
| |
| // Set true by caches when they cache content that's derived from the current pixels. |
| std::atomic<bool> fAddedToCache; |
| |
| enum Mutability { |
| 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 temporary immutable methods above. |
| |
| void setImmutableWithID(uint32_t genID); |
| friend void SkBitmapCache_setImmutableWithID(SkPixelRef*, uint32_t); |
| |
| using INHERITED = SkRefCnt; |
| }; |
| |
| #endif |