| /* |
| * 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 "SkBitmap.h" |
| #include "SkRefCnt.h" |
| #include "SkString.h" |
| #include "SkFlattenable.h" |
| #include "SkImageInfo.h" |
| #include "SkTDArray.h" |
| |
| //#define xed |
| |
| #ifdef SK_DEBUG |
| /** |
| * Defining SK_IGNORE_PIXELREF_SETPRELOCKED will force all pixelref |
| * subclasses to correctly handle lock/unlock pixels. For performance |
| * reasons, simple malloc-based subclasses call setPreLocked() to skip |
| * the overhead of implementing these calls. |
| * |
| * This build-flag disables that optimization, to add in debugging our |
| * call-sites, to ensure that they correctly balance their calls of |
| * lock and unlock. |
| */ |
| // #define SK_IGNORE_PIXELREF_SETPRELOCKED |
| #endif |
| |
| class SkColorTable; |
| class SkData; |
| struct SkIRect; |
| class SkMutex; |
| |
| class GrTexture; |
| |
| /** \class SkPixelRef |
| |
| This class is the smart container for pixel memory, and is used with |
| SkBitmap. A pixelref is installed into a bitmap, and then the bitmap can |
| access the actual pixel memory by calling lockPixels/unlockPixels. |
| |
| This class can be shared/accessed between multiple threads. |
| */ |
| class SK_API SkPixelRef : public SkFlattenable { |
| public: |
| SK_DECLARE_INST_COUNT(SkPixelRef) |
| |
| explicit SkPixelRef(const SkImageInfo&); |
| SkPixelRef(const SkImageInfo&, SkBaseMutex* mutex); |
| virtual ~SkPixelRef(); |
| |
| const SkImageInfo& info() const { |
| return fInfo; |
| } |
| |
| /** Return the pixel memory returned from lockPixels, or null if the |
| lockCount is 0. |
| */ |
| void* pixels() const { return fRec.fPixels; } |
| |
| /** Return the current colorTable (if any) if pixels are locked, or null. |
| */ |
| SkColorTable* colorTable() const { return fRec.fColorTable; } |
| |
| size_t rowBytes() const { return fRec.fRowBytes; } |
| |
| /** |
| * To access the actual pixels of a pixelref, it must be "locked". |
| * Calling lockPixels returns a LockRec struct (on success). |
| */ |
| struct LockRec { |
| void* fPixels; |
| SkColorTable* fColorTable; |
| size_t fRowBytes; |
| |
| void zero() { sk_bzero(this, sizeof(*this)); } |
| |
| bool isZero() const { |
| return NULL == fPixels && NULL == fColorTable && 0 == fRowBytes; |
| } |
| }; |
| |
| /** |
| * Returns true if the lockcount > 0 |
| */ |
| bool isLocked() const { return fLockCount > 0; } |
| |
| SkDEBUGCODE(int getLockCount() const { return fLockCount; }) |
| |
| /** |
| * Call to access the pixel memory. Return true on success. Balance this |
| * with a call to unlockPixels(). |
| */ |
| bool lockPixels(); |
| |
| /** |
| * Call to access the pixel memory. On success, return true and fill out |
| * the specified rec. On failure, return false and ignore the rec parameter. |
| * Balance this with a call to unlockPixels(). |
| */ |
| bool lockPixels(LockRec* rec); |
| |
| /** Call to balanace a previous call to lockPixels(). Returns the pixels |
| (or null) after the unlock. NOTE: lock calls can be nested, but the |
| matching number of unlock calls must be made in order to free the |
| memory (if the subclass implements caching/deferred-decoding.) |
| */ |
| void unlockPixels(); |
| |
| /** |
| * Some bitmaps can return a copy of their pixels for lockPixels(), but |
| * that copy, if modified, will not be pushed back. These bitmaps should |
| * not be used as targets for a raster device/canvas (since all pixels |
| * modifications will be lost when unlockPixels() is called.) |
| */ |
| bool lockPixelsAreWritable() const; |
| |
| /** 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(); |
| |
| /** |
| * Change the info's AlphaType. Note that this does not automatically |
| * invalidate the generation ID. If the pixel values themselves have |
| * changed, then you must explicitly call notifyPixelsChanged() as well. |
| */ |
| void changeAlphaType(SkAlphaType at); |
| |
| /** 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 fIsImmutable; } |
| |
| /** 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(); |
| |
| /** Return the optional URI string associated with this pixelref. May be |
| null. |
| */ |
| const char* getURI() const { return fURI.size() ? fURI.c_str() : NULL; } |
| |
| /** Copy a URI string to this pixelref, or clear the URI if the uri is null |
| */ |
| void setURI(const char uri[]) { |
| fURI.set(uri); |
| } |
| |
| /** Copy a URI string to this pixelref |
| */ |
| void setURI(const char uri[], size_t len) { |
| fURI.set(uri, len); |
| } |
| |
| /** Assign a URI string to this pixelref. |
| */ |
| void setURI(const SkString& uri) { fURI = uri; } |
| |
| /** |
| * If the pixelRef has an encoded (i.e. compressed) representation, |
| * return a ref to its data. If the pixelRef |
| * is uncompressed or otherwise does not have this form, return NULL. |
| * |
| * If non-null is returned, the caller is responsible for calling unref() |
| * on the data when it is finished. |
| */ |
| SkData* refEncodedData() { |
| return this->onRefEncodedData(); |
| } |
| |
| /** |
| * Experimental -- tells the caller if it is worth it to call decodeInto(). |
| * Just an optimization at this point, to avoid checking the cache first. |
| * We may remove/change this call in the future. |
| */ |
| bool implementsDecodeInto() { |
| return this->onImplementsDecodeInto(); |
| } |
| |
| /** |
| * Return a decoded instance of this pixelRef in bitmap. If this cannot be |
| * done, return false and the bitmap parameter is ignored/unchanged. |
| * |
| * pow2 is the requeste power-of-two downscale that the caller needs. This |
| * can be ignored, and the "original" size can be returned, but if the |
| * underlying codec can efficiently return a smaller size, that should be |
| * done. Some examples: |
| * |
| * To request the "base" version (original scale), pass 0 for pow2 |
| * To request 1/2 scale version (1/2 width, 1/2 height), pass 1 for pow2 |
| * To request 1/4 scale version (1/4 width, 1/4 height), pass 2 for pow2 |
| * ... |
| * |
| * If this returns true, then bitmap must be "locked" such that |
| * bitmap->getPixels() will return the correct address. |
| */ |
| bool decodeInto(int pow2, SkBitmap* bitmap) { |
| SkASSERT(pow2 >= 0); |
| return this->onDecodeInto(pow2, bitmap); |
| } |
| |
| /** Are we really wrapping a texture instead of a bitmap? |
| */ |
| virtual GrTexture* getTexture() { return NULL; } |
| |
| bool readPixels(SkBitmap* dst, const SkIRect* subset = NULL); |
| |
| /** |
| * Makes a deep copy of this PixelRef, respecting the requested config. |
| * @param colorType Desired colortype. |
| * @param subset Subset of this PixelRef to copy. Must be fully contained within the bounds of |
| * of this PixelRef. |
| * @return A new SkPixelRef, or NULL if either there is an error (e.g. the destination could |
| * not be created with the given config), or this PixelRef does not support deep |
| * copies. |
| */ |
| virtual SkPixelRef* deepCopy(SkColorType colortype, const SkIRect* subset) { |
| return NULL; |
| } |
| |
| #ifdef SK_BUILD_FOR_ANDROID |
| /** |
| * Acquire a "global" ref on this object. |
| * The default implementation just calls ref(), but subclasses can override |
| * this method to implement additional behavior. |
| */ |
| virtual void globalRef(void* data=NULL); |
| |
| /** |
| * Release a "global" ref on this object. |
| * The default implementation just calls unref(), but subclasses can override |
| * this method to implement additional behavior. |
| */ |
| virtual void globalUnref(); |
| #endif |
| |
| SK_DEFINE_FLATTENABLE_TYPE(SkPixelRef) |
| |
| // 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); |
| |
| protected: |
| /** |
| * On success, returns true and fills out the LockRec for the pixels. On |
| * failure returns false and ignores the LockRec parameter. |
| * |
| * The caller will have already acquired a mutex for thread safety, so this |
| * method need not do that. |
| */ |
| virtual bool onNewLockPixels(LockRec*) = 0; |
| |
| /** |
| * Balancing the previous successful call to onNewLockPixels. The locked |
| * pixel address will no longer be referenced, so the subclass is free to |
| * move or discard that memory. |
| * |
| * The caller will have already acquired a mutex for thread safety, so this |
| * method need not do that. |
| */ |
| virtual void onUnlockPixels() = 0; |
| |
| /** Default impl returns true */ |
| virtual bool onLockPixelsAreWritable() const; |
| |
| // returns false; |
| virtual bool onImplementsDecodeInto(); |
| // returns false; |
| virtual bool onDecodeInto(int pow2, SkBitmap* bitmap); |
| |
| /** |
| * For pixelrefs that don't have access to their raw pixels, they may be |
| * able to make a copy of them (e.g. if the pixels are on the GPU). |
| * |
| * The base class implementation returns false; |
| */ |
| virtual bool onReadPixels(SkBitmap* dst, const SkIRect* subsetOrNull); |
| |
| // default impl returns NULL. |
| virtual SkData* onRefEncodedData(); |
| |
| /** |
| * Returns the size (in bytes) of the internally allocated memory. |
| * This should be implemented in all serializable SkPixelRef derived classes. |
| * SkBitmap::fPixelRefOffset + SkBitmap::getSafeSize() should never overflow this value, |
| * otherwise the rendering code may attempt to read memory out of bounds. |
| * |
| * @return default impl returns 0. |
| */ |
| virtual size_t getAllocatedSizeInBytes() const; |
| |
| /** Return the mutex associated with this pixelref. This value is assigned |
| in the constructor, and cannot change during the lifetime of the object. |
| */ |
| SkBaseMutex* mutex() const { return fMutex; } |
| |
| // serialization |
| SkPixelRef(SkReadBuffer&, SkBaseMutex*); |
| virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE; |
| |
| // only call from constructor. Flags this to always be locked, removing |
| // the need to grab the mutex and call onLockPixels/onUnlockPixels. |
| // Performance tweak to avoid those calls (esp. in multi-thread use case). |
| void setPreLocked(void*, size_t rowBytes, SkColorTable*); |
| |
| private: |
| SkBaseMutex* fMutex; // must remain in scope for the life of this object |
| |
| // mostly const. fInfo.fAlpahType can be changed at runtime. |
| const SkImageInfo fInfo; |
| |
| // LockRec is only valid if we're in a locked state (isLocked()) |
| LockRec fRec; |
| int fLockCount; |
| |
| mutable uint32_t fGenerationID; |
| mutable bool fUniqueGenerationID; |
| |
| SkTDArray<GenIDChangeListener*> fGenIDChangeListeners; // pointers are owned |
| |
| SkString fURI; |
| |
| // can go from false to true, but never from true to false |
| bool fIsImmutable; |
| // only ever set in constructor, const after that |
| bool fPreLocked; |
| |
| void needsNewGenID(); |
| void callGenIDChangeListeners(); |
| |
| void setMutex(SkBaseMutex* mutex); |
| |
| // When copying a bitmap to another with the same shape and config, we can safely |
| // clone the pixelref generation ID too, which makes them equivalent under caching. |
| friend class SkBitmap; // only for cloneGenID |
| void cloneGenID(const SkPixelRef&); |
| |
| typedef SkFlattenable INHERITED; |
| }; |
| |
| class SkPixelRefFactory : public SkRefCnt { |
| public: |
| /** |
| * Allocate a new pixelref matching the specified ImageInfo, allocating |
| * the memory for the pixels. If the ImageInfo requires a ColorTable, |
| * the pixelref will ref() the colortable. |
| * On failure return NULL. |
| */ |
| virtual SkPixelRef* create(const SkImageInfo&, SkColorTable*) = 0; |
| }; |
| |
| #endif |