86 lines
1.9 KiB
C++
86 lines
1.9 KiB
C++
/*
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* Copyright (c) 2010 Erin Catto http://www.box2d.org
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*/
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#ifndef B2_GROWABLE_STACK_H
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#define B2_GROWABLE_STACK_H
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#include "Box2D/Common/b2Settings.h"
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#include <string.h>
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/// This is a growable LIFO stack with an initial capacity of N.
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/// If the stack size exceeds the initial capacity, the heap is used
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/// to increase the size of the stack.
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template <typename T, int32 N>
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class b2GrowableStack
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{
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public:
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b2GrowableStack()
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{
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m_stack = m_array;
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m_count = 0;
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m_capacity = N;
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}
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~b2GrowableStack()
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{
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if (m_stack != m_array)
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{
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b2Free(m_stack);
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m_stack = nullptr;
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}
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}
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void Push(const T& element)
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{
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if (m_count == m_capacity)
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{
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T* old = m_stack;
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m_capacity *= 2;
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m_stack = (T*)b2Alloc(m_capacity * sizeof(T));
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memcpy(m_stack, old, m_count * sizeof(T));
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if (old != m_array)
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{
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b2Free(old);
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}
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}
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m_stack[m_count] = element;
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++m_count;
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}
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T Pop()
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{
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b2Assert(m_count > 0);
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--m_count;
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return m_stack[m_count];
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}
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int32 GetCount()
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{
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return m_count;
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}
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private:
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T* m_stack;
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T m_array[N];
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int32 m_count;
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int32 m_capacity;
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};
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#endif
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