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