virtualx-engine/thirdparty/recastnavigation/Recast/Include/RecastAlloc.h

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//
// Copyright (c) 2009-2010 Mikko Mononen memon@inside.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 RECASTALLOC_H
#define RECASTALLOC_H
#include <stddef.h>
#include <stdint.h>
#include "RecastAssert.h"
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/// Provides hint values to the memory allocator on how long the
/// memory is expected to be used.
enum rcAllocHint
{
RC_ALLOC_PERM, ///< Memory will persist after a function call.
RC_ALLOC_TEMP ///< Memory used temporarily within a function.
};
/// A memory allocation function.
// @param[in] size The size, in bytes of memory, to allocate.
// @param[in] rcAllocHint A hint to the allocator on how long the memory is expected to be in use.
// @return A pointer to the beginning of the allocated memory block, or null if the allocation failed.
/// @see rcAllocSetCustom
typedef void* (rcAllocFunc)(size_t size, rcAllocHint hint);
/// A memory deallocation function.
/// @param[in] ptr A pointer to a memory block previously allocated using #rcAllocFunc.
/// @see rcAllocSetCustom
typedef void (rcFreeFunc)(void* ptr);
/// Sets the base custom allocation functions to be used by Recast.
/// @param[in] allocFunc The memory allocation function to be used by #rcAlloc
/// @param[in] freeFunc The memory de-allocation function to be used by #rcFree
void rcAllocSetCustom(rcAllocFunc *allocFunc, rcFreeFunc *freeFunc);
/// Allocates a memory block.
/// @param[in] size The size, in bytes of memory, to allocate.
/// @param[in] hint A hint to the allocator on how long the memory is expected to be in use.
/// @return A pointer to the beginning of the allocated memory block, or null if the allocation failed.
/// @see rcFree
void* rcAlloc(size_t size, rcAllocHint hint);
/// Deallocates a memory block.
/// @param[in] ptr A pointer to a memory block previously allocated using #rcAlloc.
/// @see rcAlloc
void rcFree(void* ptr);
/// An implementation of operator new usable for placement new. The default one is part of STL (which we don't use).
/// rcNewTag is a dummy type used to differentiate our operator from the STL one, in case users import both Recast
/// and STL.
struct rcNewTag {};
inline void* operator new(size_t, const rcNewTag&, void* p) { return p; }
inline void operator delete(void*, const rcNewTag&, void*) {}
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/// Signed to avoid warnnings when comparing to int loop indexes, and common error with comparing to zero.
/// MSVC2010 has a bug where ssize_t is unsigned (!!!).
typedef intptr_t rcSizeType;
#define RC_SIZE_MAX INTPTR_MAX
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/// Macros to hint to the compiler about the likeliest branch. Please add a benchmark that demonstrates a performance
/// improvement before introducing use cases.
#if defined(__GNUC__) || defined(__clang__)
#define rcLikely(x) __builtin_expect((x), true)
#define rcUnlikely(x) __builtin_expect((x), false)
#else
#define rcLikely(x) (x)
#define rcUnlikely(x) (x)
#endif
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/// Variable-sized storage type. Mimics the interface of std::vector<T> with some notable differences:
/// * Uses rcAlloc()/rcFree() to handle storage.
/// * No support for a custom allocator.
/// * Uses signed size instead of size_t to avoid warnings in for loops: "for (int i = 0; i < foo.size(); i++)"
/// * Omits methods of limited utility: insert/erase, (bad performance), at (we don't use exceptions), operator=.
/// * assign() and the pre-sizing constructor follow C++11 semantics -- they don't construct a temporary if no value is provided.
/// * push_back() and resize() support adding values from the current vector. Range-based constructors and assign(begin, end) do not.
/// * No specialization for bool.
template <typename T, rcAllocHint H>
class rcVectorBase {
rcSizeType m_size;
rcSizeType m_cap;
T* m_data;
// Constructs a T at the give address with either the copy constructor or the default.
static void construct(T* p, const T& v) { ::new(rcNewTag(), (void*)p) T(v); }
static void construct(T* p) { ::new(rcNewTag(), (void*)p) T; }
static void construct_range(T* begin, T* end);
static void construct_range(T* begin, T* end, const T& value);
static void copy_range(T* dst, const T* begin, const T* end);
void destroy_range(rcSizeType begin, rcSizeType end);
// Creates an array of the given size, copies all of this vector's data into it, and returns it.
T* allocate_and_copy(rcSizeType size);
void resize_impl(rcSizeType size, const T* value);
// Requires: min_capacity > m_cap.
rcSizeType get_new_capacity(rcSizeType min_capacity);
public:
typedef rcSizeType size_type;
typedef T value_type;
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rcVectorBase() : m_size(0), m_cap(0), m_data(0) {}
rcVectorBase(const rcVectorBase<T, H>& other) : m_size(0), m_cap(0), m_data(0) { assign(other.begin(), other.end()); }
explicit rcVectorBase(rcSizeType count) : m_size(0), m_cap(0), m_data(0) { resize(count); }
rcVectorBase(rcSizeType count, const T& value) : m_size(0), m_cap(0), m_data(0) { resize(count, value); }
rcVectorBase(const T* begin, const T* end) : m_size(0), m_cap(0), m_data(0) { assign(begin, end); }
~rcVectorBase() { destroy_range(0, m_size); rcFree(m_data); }
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// Unlike in std::vector, we return a bool to indicate whether the alloc was successful.
bool reserve(rcSizeType size);
void assign(rcSizeType count, const T& value) { clear(); resize(count, value); }
void assign(const T* begin, const T* end);
void resize(rcSizeType size) { resize_impl(size, NULL); }
void resize(rcSizeType size, const T& value) { resize_impl(size, &value); }
// Not implemented as resize(0) because resize requires T to be default-constructible.
void clear() { destroy_range(0, m_size); m_size = 0; }
void push_back(const T& value);
void pop_back() { rcAssert(m_size > 0); back().~T(); m_size--; }
rcSizeType size() const { return m_size; }
rcSizeType capacity() const { return m_cap; }
bool empty() const { return size() == 0; }
const T& operator[](rcSizeType i) const { rcAssert(i >= 0 && i < m_size); return m_data[i]; }
T& operator[](rcSizeType i) { rcAssert(i >= 0 && i < m_size); return m_data[i]; }
const T& front() const { rcAssert(m_size); return m_data[0]; }
T& front() { rcAssert(m_size); return m_data[0]; }
const T& back() const { rcAssert(m_size); return m_data[m_size - 1]; }
T& back() { rcAssert(m_size); return m_data[m_size - 1]; }
const T* data() const { return m_data; }
T* data() { return m_data; }
T* begin() { return m_data; }
T* end() { return m_data + m_size; }
const T* begin() const { return m_data; }
const T* end() const { return m_data + m_size; }
void swap(rcVectorBase<T, H>& other);
// Explicitly deleted.
rcVectorBase& operator=(const rcVectorBase<T, H>& other);
};
template<typename T, rcAllocHint H>
bool rcVectorBase<T, H>::reserve(rcSizeType count) {
if (count <= m_cap) {
return true;
}
T* new_data = allocate_and_copy(count);
if (!new_data) {
return false;
}
destroy_range(0, m_size);
rcFree(m_data);
m_data = new_data;
m_cap = count;
return true;
}
template <typename T, rcAllocHint H>
T* rcVectorBase<T, H>::allocate_and_copy(rcSizeType size) {
rcAssert(RC_SIZE_MAX / static_cast<rcSizeType>(sizeof(T)) >= size);
T* new_data = static_cast<T*>(rcAlloc(sizeof(T) * size, H));
if (new_data) {
copy_range(new_data, m_data, m_data + m_size);
}
return new_data;
}
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::assign(const T* begin, const T* end) {
clear();
reserve(end - begin);
m_size = end - begin;
copy_range(m_data, begin, end);
}
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::push_back(const T& value) {
// rcLikely increases performance by ~50% on BM_rcVector_PushPreallocated,
// and by ~2-5% on BM_rcVector_Push.
if (rcLikely(m_size < m_cap)) {
construct(m_data + m_size++, value);
return;
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}
const rcSizeType new_cap = get_new_capacity(m_cap + 1);
T* data = allocate_and_copy(new_cap);
// construct between allocate and destroy+free in case value is
// in this vector.
construct(data + m_size, value);
destroy_range(0, m_size);
m_size++;
m_cap = new_cap;
rcFree(m_data);
m_data = data;
}
template <typename T, rcAllocHint H>
rcSizeType rcVectorBase<T, H>::get_new_capacity(rcSizeType min_capacity) {
rcAssert(min_capacity <= RC_SIZE_MAX);
if (rcUnlikely(m_cap >= RC_SIZE_MAX / 2))
return RC_SIZE_MAX;
return 2 * m_cap > min_capacity ? 2 * m_cap : min_capacity;
}
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::resize_impl(rcSizeType size, const T* value) {
if (size < m_size) {
destroy_range(size, m_size);
m_size = size;
} else if (size > m_size) {
if (size <= m_cap) {
if (value) {
construct_range(m_data + m_size, m_data + size, *value);
} else {
construct_range(m_data + m_size, m_data + size);
}
m_size = size;
} else {
const rcSizeType new_cap = get_new_capacity(size);
T* new_data = allocate_and_copy(new_cap);
// We defer deconstructing/freeing old data until after constructing
// new elements in case "value" is there.
if (value) {
construct_range(new_data + m_size, new_data + size, *value);
} else {
construct_range(new_data + m_size, new_data + size);
}
destroy_range(0, m_size);
rcFree(m_data);
m_data = new_data;
m_cap = new_cap;
m_size = size;
}
}
}
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::swap(rcVectorBase<T, H>& other) {
// TODO: Reorganize headers so we can use rcSwap here.
rcSizeType tmp_cap = other.m_cap;
rcSizeType tmp_size = other.m_size;
T* tmp_data = other.m_data;
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other.m_cap = m_cap;
other.m_size = m_size;
other.m_data = m_data;
m_cap = tmp_cap;
m_size = tmp_size;
m_data = tmp_data;
}
// static
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::construct_range(T* begin, T* end) {
for (T* p = begin; p < end; p++) {
construct(p);
}
}
// static
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::construct_range(T* begin, T* end, const T& value) {
for (T* p = begin; p < end; p++) {
construct(p, value);
}
}
// static
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::copy_range(T* dst, const T* begin, const T* end) {
for (rcSizeType i = 0 ; i < end - begin; i++) {
construct(dst + i, begin[i]);
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}
}
template <typename T, rcAllocHint H>
void rcVectorBase<T, H>::destroy_range(rcSizeType begin, rcSizeType end) {
for (rcSizeType i = begin; i < end; i++) {
m_data[i].~T();
}
}
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template <typename T>
class rcTempVector : public rcVectorBase<T, RC_ALLOC_TEMP> {
typedef rcVectorBase<T, RC_ALLOC_TEMP> Base;
public:
rcTempVector() : Base() {}
explicit rcTempVector(rcSizeType size) : Base(size) {}
rcTempVector(rcSizeType size, const T& value) : Base(size, value) {}
rcTempVector(const rcTempVector<T>& other) : Base(other) {}
rcTempVector(const T* begin, const T* end) : Base(begin, end) {}
};
template <typename T>
class rcPermVector : public rcVectorBase<T, RC_ALLOC_PERM> {
typedef rcVectorBase<T, RC_ALLOC_PERM> Base;
public:
rcPermVector() : Base() {}
explicit rcPermVector(rcSizeType size) : Base(size) {}
rcPermVector(rcSizeType size, const T& value) : Base(size, value) {}
rcPermVector(const rcPermVector<T>& other) : Base(other) {}
rcPermVector(const T* begin, const T* end) : Base(begin, end) {}
};
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/// Legacy class. Prefer rcVector<int>.
class rcIntArray
{
rcTempVector<int> m_impl;
public:
rcIntArray() {}
rcIntArray(int n) : m_impl(n, 0) {}
void push(int item) { m_impl.push_back(item); }
void resize(int size) { m_impl.resize(size); }
void clear() { m_impl.clear(); }
int pop()
{
int v = m_impl.back();
m_impl.pop_back();
return v;
}
int size() const { return static_cast<int>(m_impl.size()); }
int& operator[](int index) { return m_impl[index]; }
int operator[](int index) const { return m_impl[index]; }
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};
/// A simple helper class used to delete an array when it goes out of scope.
/// @note This class is rarely if ever used by the end user.
template<class T> class rcScopedDelete
{
T* ptr;
public:
/// Constructs an instance with a null pointer.
inline rcScopedDelete() : ptr(0) {}
/// Constructs an instance with the specified pointer.
/// @param[in] p An pointer to an allocated array.
inline rcScopedDelete(T* p) : ptr(p) {}
inline ~rcScopedDelete() { rcFree(ptr); }
/// The root array pointer.
/// @return The root array pointer.
inline operator T*() { return ptr; }
private:
// Explicitly disabled copy constructor and copy assignment operator.
rcScopedDelete(const rcScopedDelete&);
rcScopedDelete& operator=(const rcScopedDelete&);
};
#endif