base_funcs.hh

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/*
 * LEGAL:   COPYRIGHT (C) 2004 JIM E. BROOKS
 *          THIS SOURCE CODE IS RELEASED UNDER THE TERMS
 *          OF THE GNU GENERAL PUBLIC LICENSE VERSION 2 (GPL 2).
 *****************************************************************************/

#ifndef DOXYGEN  // doxygen can't parse this correctly
#ifndef BASE_FUNCS_HH
#define BASE_FUNCS_HH 1

namespace base {


// Min()/Max() is strongly recommended and faster if either arg is a computation,
// but requires both args to be the same type.
// Macro MIN()/MAX() lets the compiler automatically convert args of different types,
// but be warned: has the well-known side-effect of compiling each arg twice!
template<typename T> inline T Min( T a, T b ) { return (a < b) ? a : b; }
template<typename T> inline T Max( T a, T b ) { return (a > b) ? a : b; }
#ifndef MIN
#define MIN(A,B) ( ((A) < (B)) ? (A) : (B) )
#endif
#ifndef MAX
#define MAX(A,B) ( ((A) > (B)) ? (A) : (B) )
#endif

// Uses overloaded abs() from <cmath>.
#define ABS(X) abs((X))

// DEPRECATED
#ifndef STREQ
#define STREQ(A,B) ( strcmp((A),(B)) == 0 )
#endif
#ifndef STRNE
#define STRNE(A,B) ( strcmp((A),(B)) != 0 )
#endif
#ifndef STREMPTY
#define STREMPTY(S) ( ((S) == NULL) || ((S)[0] == '\0') )
#endif
#ifndef MEMEQ
#define MEMEQ(S1,S2,LEN) ( memcmp((S1),(S2),(LEN)) == 0 )
#endif
#ifndef MENNE
#define MEMNE(S1,S2,LEN) ( memcmp((S1),(S2),(LEN)) != 0 )
#endif
#define ELEMS(ARRAY) (uint( sizeof((ARRAY)) / sizeof((ARRAY)[0]) ))  // DEPRECATED

// Read/write 32-bits by pointer portably.
#define READ_UINT32( PTR )       ( (*reinterpret_cast<uint32*>((PTR))) )
#define WRITE_UINT32( PTR, VAL ) ( (*reinterpret_cast<uint32*>((PTR))) = (VAL) )
#define COPY_UINT32( DEST, SRC ) ( (*reinterpret_cast<uint32*>((DEST))) = (*reinterpret_cast<const uint32*>((SRC))) )

#define DELETE_NULL( OBJ ) delete (OBJ), (OBJ) = NULL

#define RETURN_LT_TRUE_GT_FALSE( X, Y )         \
{                                               \
    if ( (X) < (Y) ) return true;               \
    if ( (Y) < (X) ) return false;              \
}

// Put this in destructors of globals which may call other globals
// to avoid pitfall of undefined order of destruction.
#define RETURN_IF_EXITING  if ( base::global.mExiting ) return;

// In case some cleanup function should be called instead.
void EXIT( int exitCode );

#define CLEAR_BIT_FIELDS( BIT_FIELD_PTR ) ( *(reinterpret_cast<unsigned int*>( (BIT_FIELD_PTR) )) = 0 )

// Arcane indirect trick to give a variable a unique name.
// Subtlety: If written on the same line, UNIQUE_NAME() expands the same name.
// That's a feature not a bug.  BEGIN_ONCE depends on it.
#define UNIQUE_NAME__(NAME,LINE) NAME##LINE
#define UNIQUE_NAME_(NAME,LINE)  UNIQUE_NAME__(NAME,LINE)
#define UNIQUE_NAME(NAME)        UNIQUE_NAME_(NAME,__LINE__)

// BEGIN_ONCE {  <-- write brace  // thread-safe
// ...
// } END_ONCE
// Subtlety: This must be one-line because of UNIQUE_NAME().
// Needs to be locked since BEGIN_ONCE is often placed in threadable code.
#define BEGIN_ONCE                          \
 {                                          \
    PERSISTENT FastLock sLockOnce_;         \
    FastLock::Auto autolock(&sLockOnce_);   \
    PERSISTENT int UNIQUE_NAME(once);       \
    ++UNIQUE_NAME(once);                    \
    if ( UNIQUE_NAME(once) == 1 )

#define END_ONCE \
 }

#if __GNUC__ >= 3
#define likely(x)   __builtin_expect((x),1)
#define unlikely(x) __builtin_expect((x),0)
#else
#define likely(x) (x)
#define unlikely(x) (x)
#endif
#define EX(x) likely((x))   
#define UX(x) unlikely((x)) 

#if GCC_VERSION >= 30100  // if gcc-3.1 or later
#define UNUSED    __attribute__ ((unused))
#define DEBUG_VAR __attribute__ ((unused))
#define NOINLINE  __attribute__ ((noinline))
#else
#define UNUSED
#define DEBUG_VAR
#define NOINLINE
#endif

#if DEBUG
#define  CODE
#else
#define 
#endif

// Pedantic excruciatingly slow debug code.
#if DEBUG == 2
#define  CODE
#else
#define 
#endif

// To mark where code needs implementing.
#define UNIMPLEMENTED() ASSERT(0)

// C++ stream field formatting.
#define OMANIP_FIELD(CHARS) std::setw(CHARS) << std::right

// Prevent copying an object.  Put these in the private section of a class.
// The copy methods are prototypes without definitions, so usage causes a linker error.
#define                     \
private:                                            \
    CLASS( const CLASS& );                          \
    CLASS& operator=( const CLASS& );

// To mark classes that are copyable.
#define           // means class is copyable by user-defined copying methods
#define   // means class is copyable by compiler-generated copying methods
#define      // synonym

// To mark class that shouldn't be instantiated
#define PREVENT_INSTANTIATING( CLASS )  // NOP
#define PREVENT_INSTANCE( CLASS )  // NOP


INLINE void
CLEAR( void* p, uint n )
{
    memset( p, 0, n );
}

INLINE int         NEG( int         x ) { return (x < 0) ? x : -x; }
INLINE long int    NEG( long int    x ) { return (x < 0) ? x : -x; }
INLINE float       NEG( float       x ) { return (x < 0) ? x : -x; }
INLINE double      NEG( double      x ) { return (x < 0) ? x : -x; }
INLINE long double NEG( long double x ) { return (x < 0) ? x : -x; }

INLINE bool
IfPow2( int n )
{
    // Trick: result is 0 if n is a power of 2.
    return (n & (n-1)) == 0;
}

INLINE bool IfEven( int n ) { return (n & 1) == 0; }
INLINE bool IfOdd( int n )  { return (n & 1) == 1; }

// +1 or -1 if true or false
INLINE int
PLUS_MINUS_1( bool plus )
{
    return plus ? 1 : -1;
}


template<typename T>
inline void
Swap( T& a, T& b )
{
    T a2 = a;
    a = b;
    b = a2;
}

} // namespace base

#endif // BASE_FUNCS_HH
#endif // DOXYGEN

Palomino 3D Engine documents generated by doxygen 1.5.3 on Fri Nov 23 11:26:06 2007