rubidium@5838: /* $Id$ */
rubidium@5838: 
KUDr@6285: /** @file helpers.hpp */
KUDr@6285: 
rubidium@5838: #ifndef HELPERS_HPP
rubidium@5838: #define HELPERS_HPP
rubidium@5838: 
rubidium@5838: #include "macros.h"
rubidium@5838: 
rubidium@5838: /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value
rubidium@5838: *  from void* to the proper pointer type. Another alternative would be MallocT<> as follows */
KUDr@5860: template <typename T> FORCEINLINE T* MallocT(size_t num_elements)
rubidium@5838: {
KUDr@5860: 	T *t_ptr = (T*)malloc(num_elements * sizeof(T));
KUDr@5860: 	return t_ptr;
rubidium@5838: }
rubidium@5838: /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value
rubidium@5838: *  from void* to the proper pointer type. Another alternative would be MallocT<> as follows */
KUDr@5860: template <typename T> FORCEINLINE T* CallocT(size_t num_elements)
rubidium@5838: {
KUDr@5860: 	T *t_ptr = (T*)calloc(num_elements, sizeof(T));
KUDr@5860: 	return t_ptr;
rubidium@5838: }
rubidium@5838: /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value
rubidium@5838: *  from void* to the proper pointer type. Another alternative would be MallocT<> as follows */
KUDr@5860: template <typename T> FORCEINLINE T* ReallocT(T* t_ptr, size_t num_elements)
rubidium@5838: {
KUDr@5860: 	t_ptr = (T*)realloc(t_ptr, num_elements * sizeof(T));
KUDr@5860: 	return t_ptr;
rubidium@5838: }
rubidium@5838: 
rubidium@5838: 
tron@5984: /** type safe swap operation */
tron@5984: template<typename T> void Swap(T& a, T& b)
rubidium@5838: {
tron@5984: 	T t = a;
tron@5984: 	a = b;
tron@5984: 	b = t;
rubidium@5838: }
rubidium@5838: 
rubidium@5838: 
rubidium@5838: /** returns the absolute value of (scalar) variable. @note assumes variable to be signed */
rubidium@5838: template <typename T> static inline T myabs(T a) { return a < (T)0 ? -a : a; }
rubidium@5838: /** returns the (absolute) difference between two (scalar) variables */
rubidium@5838: template <typename T> static inline T delta(T a, T b) { return a < b ? b - a : a - b; }
rubidium@5838: 
rubidium@5838: /** Some enums need to have allowed incrementing (i.e. StationClassID) */
rubidium@5838: #define DECLARE_POSTFIX_INCREMENT(type) \
rubidium@5838: 	FORCEINLINE type operator ++(type& e, int) \
rubidium@5838: 	{ \
rubidium@5838: 		type e_org = e; \
rubidium@5838: 		e = (type)((int)e + 1); \
rubidium@5838: 		return e_org; \
rubidium@5838: 	} \
rubidium@5838: 	FORCEINLINE type operator --(type& e, int) \
rubidium@5838: 	{ \
rubidium@5838: 		type e_org = e; \
rubidium@5838: 		e = (type)((int)e - 1); \
rubidium@5838: 		return e_org; \
rubidium@5838: 	}
rubidium@5838: 
rubidium@5838: 
rubidium@5838: 
rubidium@5838: /** Operators to allow to work with enum as with type safe bit set in C++ */
rubidium@5838: # define DECLARE_ENUM_AS_BIT_SET(mask_t) \
rubidium@5838: 	FORCEINLINE mask_t operator | (mask_t m1, mask_t m2) {return (mask_t)((int)m1 | m2);} \
rubidium@5838: 	FORCEINLINE mask_t operator & (mask_t m1, mask_t m2) {return (mask_t)((int)m1 & m2);} \
rubidium@5838: 	FORCEINLINE mask_t operator ^ (mask_t m1, mask_t m2) {return (mask_t)((int)m1 ^ m2);} \
rubidium@5838: 	FORCEINLINE mask_t& operator |= (mask_t& m1, mask_t m2) {m1 = m1 | m2; return m1;} \
rubidium@5838: 	FORCEINLINE mask_t& operator &= (mask_t& m1, mask_t m2) {m1 = m1 & m2; return m1;} \
rubidium@5838: 	FORCEINLINE mask_t& operator ^= (mask_t& m1, mask_t m2) {m1 = m1 ^ m2; return m1;} \
rubidium@5838: 	FORCEINLINE mask_t operator ~(mask_t m) {return (mask_t)(~(int)m);}
rubidium@5838: 
rubidium@5838: 
rubidium@5838: /** Informative template class exposing basic enumeration properties used by several
rubidium@5838:  *  other templates below. Here we have only forward declaration. For each enum type
bjarni@6268:  *  we will create specialization derived from MakeEnumPropsT<>.
bjarni@6268:  *  i.e.:
bjarni@6268:  *    template <> struct EnumPropsT<Track> : MakeEnumPropsT<Track, byte, TRACK_BEGIN, TRACK_END, INVALID_TRACK> {};
bjarni@6268:  *  followed by:
bjarni@6268:  *    typedef TinyEnumT<Track> TrackByte;
bjarni@6268:  */
rubidium@5838: template <typename Tenum_t> struct EnumPropsT;
rubidium@5838: 
rubidium@5838: /** Helper template class that makes basic properties of given enumeration type visible
rubidium@5838:  *  from outsize. It is used as base class of several EnumPropsT specializations each
bjarni@6268:  *  dedicated to one of commonly used enumeration types.
bjarni@6268:  *  @param Tenum_t enumeration type that you want to describe
bjarni@6268:  *  @param Tstorage_t what storage type would be sufficient (i.e. byte)
bjarni@6268:  *  @param Tbegin first valid value from the contiguous range (i.e. TRACK_BEGIN)
bjarni@6268:  *  @param Tend one past the last valid value from the contiguous range (i.e. TRACK_END)
bjarni@6268:  *  @param Tinvalid value used as invalid value marker (i.e. INVALID_TRACK)
bjarni@6268:  */
rubidium@5838: template <typename Tenum_t, typename Tstorage_t, Tenum_t Tbegin, Tenum_t Tend, Tenum_t Tinvalid>
rubidium@5838: struct MakeEnumPropsT {
rubidium@5838: 	typedef Tenum_t type;                     ///< enum type (i.e. Trackdir)
rubidium@5838: 	typedef Tstorage_t storage;               ///< storage type (i.e. byte)
rubidium@5838: 	static const Tenum_t begin = Tbegin;      ///< lowest valid value (i.e. TRACKDIR_BEGIN)
rubidium@5838: 	static const Tenum_t end = Tend;          ///< one after the last valid value (i.e. TRACKDIR_END)
rubidium@5838: 	static const Tenum_t invalid = Tinvalid;  ///< what value is used as invalid value (i.e. INVALID_TRACKDIR)
rubidium@5838: };
rubidium@5838: 
rubidium@5838: 
rubidium@5838: 
rubidium@5838: /** In some cases we use byte or uint16 to store values that are defined as enum. It is
rubidium@5838: 	*  necessary in order to control the sizeof() such values. Some compilers make enum
rubidium@5838: 	*  the same size as int (4 or 8 bytes instead of 1 or 2). As a consequence the strict
rubidium@5838: 	*  compiler type-checking causes errors like:
rubidium@5838: 	*     'HasPowerOnRail' : cannot convert parameter 1 from 'byte' to 'RailType' when
rubidium@5838: 	*  u->u.rail.railtype is passed as argument or type RailType. In such cases it is better
rubidium@5838: 	*  to teach the compiler that u->u.rail.railtype is to be treated as RailType. */
rubidium@5838: template <typename Tenum_t> struct TinyEnumT;
rubidium@5838: 
rubidium@5838: /** The general declaration of TinyEnumT<> (above) */
rubidium@5838: template <typename Tenum_t> struct TinyEnumT
rubidium@5838: {
rubidium@5838: 	typedef Tenum_t enum_type;                      ///< expose our enumeration type (i.e. Trackdir) to outside
rubidium@5838: 	typedef EnumPropsT<Tenum_t> Props;              ///< make easier access to our enumeration propeties
rubidium@5838: 	typedef typename Props::storage storage_type;   ///< small storage type
rubidium@5838: 	static const enum_type begin = Props::begin;    ///< enum beginning (i.e. TRACKDIR_BEGIN)
rubidium@5838: 	static const enum_type end = Props::end;        ///< enum end (i.e. TRACKDIR_END)
rubidium@5838: 	static const enum_type invalid = Props::invalid;///< invalid value (i.e. INVALID_TRACKDIR)
rubidium@5838: 
rubidium@5838: 	storage_type m_val;  ///< here we hold the actual value in small (i.e. byte) form
rubidium@5838: 
rubidium@5838: 	/** Cast operator - invoked then the value is assigned to the Tenum_t type */
rubidium@5838: 	FORCEINLINE operator enum_type () const
rubidium@5838: 	{
rubidium@5838: 		return (enum_type)m_val;
rubidium@5838: 	}
rubidium@5838: 
rubidium@5838: 	/** Assignment operator (from Tenum_t type) */
rubidium@5838: 	FORCEINLINE TinyEnumT& operator = (enum_type e)
rubidium@5838: 	{
rubidium@5838: 		m_val = (storage_type)e; return *this;
rubidium@5838: 	}
rubidium@5838: 
rubidium@5838: 	/** postfix ++ operator on tiny type */
rubidium@5838: 	FORCEINLINE TinyEnumT& operator ++ (int)
rubidium@5838: 	{
rubidium@5838: 		if (++m_val >= end) m_val -= (storage_type)(end - begin);
rubidium@5838: 		return *this;
rubidium@5838: 	}
rubidium@5838: };
rubidium@5838: 
bjarni@6268: template <typename T> void ClrBitT(T &t, int bit_index)
rubidium@5838: {
bjarni@6268: 	t = (T)(t & ~((T)1 << bit_index));
rubidium@5838: }
rubidium@5838: 
bjarni@6268: template <typename T> void SetBitT(T &t, int bit_index)
rubidium@5838: {
bjarni@6268: 	t = (T)(t | ((T)1 << bit_index));
rubidium@5838: }
rubidium@5838: 
bjarni@6268: template <typename T> void ToggleBitT(T &t, int bit_index)
rubidium@5838: {
bjarni@6268: 	t = (T)(t ^ ((T)1 << bit_index));
rubidium@5838: }
rubidium@5838: 
KUDr@6261: /**
KUDr@6261: * Zero initialization end marker.
KUDr@6261: * @see ZeroInitBegin for usage.
KUDr@6261: */
KUDr@6261: struct ZeroInitEnd {
KUDr@6261: };
KUDr@6261: 
KUDr@6261: /**
KUDr@6261:  * Zero initialization begin marker. When you need to initialize struct/class members by
KUDr@6261:  * memset(&m_first_member, 0, ((byte*)&m_last_member) - ((byte*)&m_first_member + sizeof(m_last_member));
KUDr@6261:  * place ZeroInitBegin before m_first_member, place ZeroInitEnd after m_last_member, call ZeroInitBegin
KUDr@6261:  * constructor give him ZeroInitEnd& as parameter. This will clear whole area between them using memset.
KUDr@6261:  * @see ZeroInitEnd
KUDr@6261:  */
KUDr@6261: struct ZeroInitBegin {
KUDr@6261: 	ZeroInitBegin(const ZeroInitEnd &end)
KUDr@6261: 	{
KUDr@6261: 		memset(this, 0, ((byte*)&end) - ((byte*)this));
KUDr@6261: 	}
KUDr@6261: };
KUDr@6261: 
rubidium@5838: #endif /* HELPERS_HPP */