michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef SkBitSet_DEFINED
michael@0: #define SkBitSet_DEFINED
michael@0: 
michael@0: #include "SkTypes.h"
michael@0: #include "SkTDArray.h"
michael@0: 
michael@0: class SkBitSet {
michael@0: public:
michael@0:     /** NumberOfBits must be greater than zero.
michael@0:      */
michael@0:     explicit SkBitSet(int numberOfBits);
michael@0:     explicit SkBitSet(const SkBitSet& source);
michael@0: 
michael@0:     SkBitSet& operator=(const SkBitSet& rhs);
michael@0:     bool operator==(const SkBitSet& rhs);
michael@0:     bool operator!=(const SkBitSet& rhs);
michael@0: 
michael@0:     /** Clear all data.
michael@0:      */
michael@0:     void clearAll();
michael@0: 
michael@0:     /** Set the value of the index-th bit.
michael@0:      */
michael@0:     void setBit(int index, bool value);
michael@0: 
michael@0:     /** Test if bit index is set.
michael@0:      */
michael@0:     bool isBitSet(int index) const;
michael@0: 
michael@0:     /** Or bits from source.  false is returned if this doesn't have the same
michael@0:      *  bit count as source.
michael@0:      */
michael@0:     bool orBits(const SkBitSet& source);
michael@0: 
michael@0:     /** Export indices of set bits to T array.
michael@0:      */
michael@0:     template<typename T>
michael@0:     void exportTo(SkTDArray<T>* array) const {
michael@0:         SkASSERT(array);
michael@0:         uint32_t* data = reinterpret_cast<uint32_t*>(fBitData.get());
michael@0:         for (unsigned int i = 0; i < fDwordCount; ++i) {
michael@0:             uint32_t value = data[i];
michael@0:             if (value) {  // There are set bits
michael@0:                 unsigned int index = i * 32;
michael@0:                 for (unsigned int j = 0; j < 32; ++j) {
michael@0:                     if (0x1 & (value >> j)) {
michael@0:                         array->push(index + j);
michael@0:                     }
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     SkAutoFree fBitData;
michael@0:     // Dword (32-bit) count of the bitset.
michael@0:     size_t fDwordCount;
michael@0:     size_t fBitCount;
michael@0: 
michael@0:     uint32_t* internalGet(int index) const {
michael@0:         SkASSERT((size_t)index < fBitCount);
michael@0:         size_t internalIndex = index / 32;
michael@0:         SkASSERT(internalIndex < fDwordCount);
michael@0:         return reinterpret_cast<uint32_t*>(fBitData.get()) + internalIndex;
michael@0:     }
michael@0: };
michael@0: 
michael@0: 
michael@0: #endif