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Diffstat (limited to 'dep/g3dlite/G3D/SmallArray.h')
-rw-r--r-- | dep/g3dlite/G3D/SmallArray.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/dep/g3dlite/G3D/SmallArray.h b/dep/g3dlite/G3D/SmallArray.h new file mode 100644 index 00000000000..41f9959e264 --- /dev/null +++ b/dep/g3dlite/G3D/SmallArray.h @@ -0,0 +1,155 @@ +/** + @file SmallArray.h + + @created 2009-04-26 + @edited 2009-04-26 + + Copyright 2000-2009, Morgan McGuire, http://graphics.cs.williams.edu + All rights reserved. + */ +#ifndef G3D_SmallArray_h +#define G3D_SmallArray_h + +#include "G3D/platform.h" +#include "G3D/Array.h" + +namespace G3D { + +/** Embeds \a N elements to reduce allocation time and increase + memory coherence when working with arrays of arrays. + Offers a limited subset of the functionality of G3D::Array.*/ +template<class T, int N> +class SmallArray { +private: + int m_size; + + /** First N elements */ + T m_embedded[N]; + + /** Remaining elements */ + Array<T> m_rest; + +public: + + SmallArray() : m_size(0) {} + + inline int size() const { + return m_size; + } + + void resize(int n, bool shrinkIfNecessary = true) { + m_rest.resize(std::max(0, n - N), shrinkIfNecessary); + m_size = n; + } + + void clear(bool shrinkIfNecessary = true) { + resize(0, shrinkIfNecessary); + } + + inline T& operator[](int i) { + debugAssert(i < m_size && i >= 0); + if (i < N) { + return m_embedded[i]; + } else { + return m_rest[i - N]; + } + } + + inline const T& operator[](int i) const { + debugAssert(i < m_size && i >= 0); + if (i < N) { + return m_embedded[i]; + } else { + return m_rest[i - N]; + } + } + + inline void push(const T& v) { + ++m_size; + if (m_size <= N) { + m_embedded[m_size - 1] = v; + } else { + m_rest.append(v); + } + } + + inline void append(const T& v) { + push(v); + } + + void fastRemove(int i) { + debugAssert(i < m_size && i >= 0); + if (i < N) { + if (m_size <= N) { + // Exclusively embedded + m_embedded[i] = m_embedded[m_size - 1]; + } else { + // Move one down from the rest array + m_embedded[i] = m_rest.pop(); + } + } else { + // Removing from the rest array + m_rest.fastRemove(i - N); + } + --m_size; + } + + T pop() { + debugAssert(m_size > 0); + if (m_size <= N) { + // Popping from embedded, don't need a temporary + --m_size; + return m_embedded[m_size]; + } else { + // Popping from rest + --m_size; + return m_rest.pop(); + } + } + + inline void popDiscard() { + debugAssert(m_size > 0); + if (m_size > N) { + m_rest.popDiscard(); + } + --m_size; + } + + inline T& next() { + ++m_size; + if (m_size <= N) { + return m_embedded[m_size - 1]; + } else { + return m_rest.next(); + } + } + + bool contains(const T& value) const { + for (int i = std::min(m_size, N) - 1; i >= 0; --i) { + if (m_embedded[i] == value) { + return true; + } + } + return m_rest.contains(value); + } + + template<int MIN_ELEMENTS, int MIN_BYTES> + SmallArray<T, N>& operator=(const Array<T, MIN_ELEMENTS, MIN_BYTES>& src) { + resize(src.size()); + for (int i = 0; i < src.size(); ++i) { + (*this)[i] = src[i]; + } + return *this; + } + + inline const T& last() const { + return (*this)[size() - 1]; + } + + inline T& last() { + return (*this)[size() - 1]; + } +}; + +} +#endif |