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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkBitSet_DEFINED
#define SkBitSet_DEFINED
#include "SkTypes.h"
#include "SkTDArray.h"
class SkBitSet {
public:
/** NumberOfBits must be greater than zero.
*/
explicit SkBitSet(int numberOfBits);
explicit SkBitSet(const SkBitSet& source);
SkBitSet& operator=(const SkBitSet& rhs);
bool operator==(const SkBitSet& rhs);
bool operator!=(const SkBitSet& rhs);
/** Clear all data.
*/
void clearAll();
/** Set the value of the index-th bit.
*/
void setBit(int index, bool value) {
uint32_t mask = 1 << (index & 31);
uint32_t* chunk = this->internalGet(index);
if (value) {
*chunk |= mask;
} else {
*chunk &= ~mask;
}
}
/** Test if bit index is set.
*/
bool isBitSet(int index) const {
uint32_t mask = 1 << (index & 31);
return SkToBool(*this->internalGet(index) & mask);
}
/** Or bits from source. false is returned if this doesn't have the same
* bit count as source.
*/
bool orBits(const SkBitSet& source);
/** Export indices of set bits to T array.
*/
template<typename T>
void exportTo(SkTDArray<T>* array) const {
SkASSERT(array);
uint32_t* data = reinterpret_cast<uint32_t*>(fBitData.get());
for (unsigned int i = 0; i < fDwordCount; ++i) {
uint32_t value = data[i];
if (value) { // There are set bits
unsigned int index = i * 32;
for (unsigned int j = 0; j < 32; ++j) {
if (0x1 & (value >> j)) {
array->push(index + j);
}
}
}
}
}
private:
SkAutoFree fBitData;
// Dword (32-bit) count of the bitset.
size_t fDwordCount;
size_t fBitCount;
uint32_t* internalGet(int index) const {
SkASSERT((size_t)index < fBitCount);
size_t internalIndex = index / 32;
SkASSERT(internalIndex < fDwordCount);
return reinterpret_cast<uint32_t*>(fBitData.get()) + internalIndex;
}
};
#endif
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