Bullet Collision Detection & Physics Library
btStackAlloc.h
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1/*
2Copyright (c) 2003-2006 Gino van den Bergen / Erwin Coumans http://continuousphysics.com/Bullet/
3
4This software is provided 'as-is', without any express or implied warranty.
5In no event will the authors be held liable for any damages arising from the use of this software.
6Permission is granted to anyone to use this software for any purpose,
7including commercial applications, and to alter it and redistribute it freely,
8subject to the following restrictions:
9
101. 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.
112. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
123. This notice may not be removed or altered from any source distribution.
13*/
14
15/*
16StackAlloc extracted from GJK-EPA collision solver by Nathanael Presson
17Nov.2006
18*/
19
20#ifndef BT_STACK_ALLOC
21#define BT_STACK_ALLOC
22
23#include "btScalar.h" //for btAssert
24#include "btAlignedAllocator.h"
25
27struct btBlock
28{
30 unsigned char* address;
31};
32
35{
36public:
37
38 btStackAlloc(unsigned int size) { ctor();create(size); }
40
41 inline void create(unsigned int size)
42 {
43 destroy();
44 data = (unsigned char*) btAlignedAlloc(size,16);
46 }
47 inline void destroy()
48 {
50 //Raise(L"StackAlloc is still in use");
51
52 if(usedsize==0)
53 {
54 if(!ischild && data)
56
57 data = 0;
58 usedsize = 0;
59 }
60
61 }
62
64 {
65 return static_cast<int>(totalsize - usedsize);
66 }
67
68 unsigned char* allocate(unsigned int size)
69 {
70 const unsigned int nus(usedsize+size);
71 if(nus<totalsize)
72 {
73 usedsize=nus;
74 return(data+(usedsize-size));
75 }
76 btAssert(0);
77 //&& (L"Not enough memory"));
78
79 return(0);
80 }
82 {
83 btBlock* pb = (btBlock*)allocate(sizeof(btBlock));
84 pb->previous = current;
85 pb->address = data+usedsize;
86 current = pb;
87 return(pb);
88 }
90 {
91 btAssert(block==current);
92 //Raise(L"Unmatched blocks");
93 if(block==current)
94 {
95 current = block->previous;
96 usedsize = (unsigned int)((block->address-data)-sizeof(btBlock));
97 }
98 }
99
100private:
101 void ctor()
102 {
103 data = 0;
104 totalsize = 0;
105 usedsize = 0;
106 current = 0;
107 ischild = false;
108 }
109 unsigned char* data;
110 unsigned int totalsize;
111 unsigned int usedsize;
114};
115
116#endif //BT_STACK_ALLOC
#define btAlignedFree(ptr)
#define btAlignedAlloc(size, alignment)
static DBVT_INLINE btScalar size(const btDbvtVolume &a)
Definition: btDbvt.cpp:52
#define SIMD_FORCE_INLINE
Definition: btScalar.h:81
#define btAssert(x)
Definition: btScalar.h:131
The StackAlloc class provides some fast stack-based memory allocator (LIFO last-in first-out)
Definition: btStackAlloc.h:35
btBlock * current
Definition: btStackAlloc.h:112
void destroy()
Definition: btStackAlloc.h:47
unsigned char * data
Definition: btStackAlloc.h:109
void create(unsigned int size)
Definition: btStackAlloc.h:41
btStackAlloc(unsigned int size)
Definition: btStackAlloc.h:38
unsigned char * allocate(unsigned int size)
Definition: btStackAlloc.h:68
int getAvailableMemory() const
Definition: btStackAlloc.h:63
btBlock * beginBlock()
Definition: btStackAlloc.h:81
void endBlock(btBlock *block)
Definition: btStackAlloc.h:89
unsigned int usedsize
Definition: btStackAlloc.h:111
unsigned int totalsize
Definition: btStackAlloc.h:110
The btBlock class is an internal structure for the btStackAlloc memory allocator.
Definition: btStackAlloc.h:28
unsigned char * address
Definition: btStackAlloc.h:30
btBlock * previous
Definition: btStackAlloc.h:29