base.h

// SPDX-FileCopyrightText: 2023 Erin Catto
// SPDX-License-Identifier: MIT
 
#pragma once
 
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
 
// Compile-time options. Edit box2d/config.h, or define BOX2D_USER_CONFIG to
// point at your own copy.
#ifdef BOX2D_USER_CONFIG
#include BOX2D_USER_CONFIG
#endif
#include "config.h"

#define B2_NULL_INDEX ( -1 )
 
// clang-format off
// 
// Shared library macros
// Predefine BOX2D_EXPORT to reuse an existing export/import scheme, for example
// when compiling Box2D into another shared library.
#ifndef BOX2D_EXPORT
#if defined( _WIN32 ) && defined( box2d_EXPORTS )
    // build the Windows DLL
    #define BOX2D_EXPORT __declspec( dllexport )
#elif defined( _WIN32 ) && defined( BOX2D_DLL )
    // using the Windows DLL
    #define BOX2D_EXPORT __declspec( dllimport )
#elif defined( box2d_EXPORTS )
    // building or using the shared library
    #define BOX2D_EXPORT __attribute__( ( visibility( "default" ) ) )
#else
    // static library
    #define BOX2D_EXPORT
#endif
#endif
 
// C++ macros
#ifdef __cplusplus
    #define B2_API extern "C" BOX2D_EXPORT
    #define B2_INLINE inline
    #define B2_ALIGN_AS(N) alignas(N)
#if defined( _MSC_VER )
    #define B2_FORCE_INLINE __forceinline
#elif defined( __GNUC__ ) || defined( __clang__ )
    #define B2_FORCE_INLINE inline __attribute__((always_inline))
#else
    #define B2_FORCE_INLINE inline
#endif
 
    #define B2_LITERAL(T) T
    #define B2_ZERO_INIT {}
#else
    #define B2_API BOX2D_EXPORT
    #define B2_INLINE static inline
    #define B2_ALIGN_AS(N) _Alignas(N)
 
#if defined( _MSC_VER )
    #define B2_FORCE_INLINE static __forceinline
#elif defined( __GNUC__ ) || defined( __clang__ )
    #define B2_FORCE_INLINE static inline __attribute__((always_inline))
#else
    #define B2_FORCE_INLINE static inline
#endif
 
    // Used for C literals like (b2Vec2){1.0f, 2.0f} where C++ requires b2Vec2{1.0f, 2.0f}
    #define B2_LITERAL(T) (T)
    #define B2_ZERO_INIT {0}
#endif
// clang-format on
 
#if defined( BOX2D_VALIDATE ) && !defined( NDEBUG )
#define B2_ENABLE_VALIDATION 1
#else
#define B2_ENABLE_VALIDATION 0
#endif


typedef void* b2AllocCallbackFcn( size_t size, int alignment );

typedef void b2FreeCallbackFcn( void* mem, size_t size );

typedef int b2AssertCallbackFcn( const char* condition, const char* fileName, int lineNumber );

typedef void b2LogCallbackFcn( const char* message );

B2_API void b2SetAllocator( b2AllocCallbackFcn* allocFcn, b2FreeCallbackFcn* freeFcn );

B2_API size_t b2GetByteCount( void );

B2_API void b2SetAssertCallback( b2AssertCallbackFcn* assertFcn );

B2_API void b2SetLogCallback( b2LogCallbackFcn* logFcn );

typedef struct b2Version
{
    int major;

    int minor;

    int revision;
} b2Version;

#define B2_VERSION_MAJOR 3

#define B2_VERSION_MINOR 2

#define B2_VERSION_REVISION 0

B2_API b2Version b2GetVersion( void );

B2_API bool b2IsDoublePrecision( void );

B2_API bool b2IsAVX2Available( void );


 
// see https://github.com/scottt/debugbreak
#if defined( _MSC_VER )
#define B2_BREAKPOINT __debugbreak()
#elif defined( __GNUC__ ) || defined( __clang__ )
#define B2_BREAKPOINT __builtin_trap()
#else
// Unknown compiler
#include <assert.h>
#define B2_BREAKPOINT assert( 0 )
#endif
 
#if !defined( NDEBUG ) || defined( B2_ENABLE_ASSERT )
B2_API int b2InternalAssert( const char* condition, const char* fileName, int lineNumber );
#define B2_ASSERT( condition )                                                                     \
    ( (void)( ( !!( condition ) ) ||                                                               \
              ( b2InternalAssert( #condition, __FILE__, (int)( __LINE__ ) ), 0 ) ) )
#else
#define B2_ASSERT( ... ) ( (void)0 )
#endif
 
// Validation is used in debug builds
#if B2_ENABLE_VALIDATION
#define B2_VALIDATE( condition ) B2_ASSERT( condition )
#else
#define B2_VALIDATE( ... ) ( (void)0 )
#endif


B2_API uint64_t b2GetTicks( void );

B2_API float b2GetMilliseconds( uint64_t ticks );

B2_API float b2GetMillisecondsAndReset( uint64_t* ticks );

B2_API void b2Yield( void );

#define B2_HASH_INIT 5381

B2_API uint32_t b2Hash( uint32_t hash, const uint8_t* data, int count );