celestar@5650: /* $Id$ */
celestar@5650: 
celestar@5650: #ifndef HELPERS_HPP
celestar@5650: #define HELPERS_HPP
celestar@5650: 
celestar@5650: /** @file helpers.hpp */
celestar@5650: #include "macros.h"
celestar@5650: 
celestar@5650: #ifdef __cplusplus
celestar@5650: 
celestar@5650: /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value
celestar@5650: *  from void* to the proper pointer type. Another alternative would be MallocT<> as follows */
celestar@5650: template <typename T> FORCEINLINE bool MallocT(T** t_ptr, size_t num_elements)
celestar@5650: {
celestar@5650: 	*t_ptr = (T*)malloc(num_elements * sizeof(T));
celestar@5650: 	return (*t_ptr != NULL);
celestar@5650: }
celestar@5650: /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value
celestar@5650: *  from void* to the proper pointer type. Another alternative would be MallocT<> as follows */
celestar@5650: template <typename T> FORCEINLINE bool CallocT(T** t_ptr, size_t num_elements)
celestar@5650: {
celestar@5650: 	*t_ptr = (T*)calloc(num_elements, sizeof(T));
celestar@5650: 	return (*t_ptr != NULL);
celestar@5650: }
celestar@5650: /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value
celestar@5650: *  from void* to the proper pointer type. Another alternative would be MallocT<> as follows */
celestar@5650: template <typename T> FORCEINLINE bool ReallocT(T** t_ptr, size_t num_elements)
celestar@5650: {
celestar@5650: 	*t_ptr = (T*)realloc(*t_ptr, num_elements * sizeof(T));
celestar@5650: 	return (*t_ptr != NULL);
celestar@5650: }
celestar@5650: 
celestar@5650: /** type safe swap operation */
celestar@5650: template <typename T> void SwapT(T *a, T *b);
celestar@5650: 
celestar@5650: template <typename T> FORCEINLINE void SwapT(T *a, T *b)
celestar@5650: {
celestar@5650: 	T t = *a;
celestar@5650: 	*a = *b;
celestar@5650: 	*b = t;
celestar@5650: }
celestar@5650: 
celestar@5650: 
celestar@5650: /** returns the absolute value of (scalar) variable. @note assumes variable to be signed */
celestar@5650: template <typename T> static inline T myabs(T a) { return a < (T)0 ? -a : a; }
celestar@5650: /** returns the (absolute) difference between two (scalar) variables */
celestar@5650: template <typename T> static inline T delta(T a, T b) { return a < b ? b - a : a - b; }
celestar@5650: 
celestar@5650: /** Some enums need to have allowed incrementing (i.e. StationClassID) */
celestar@5650: #define DECLARE_POSTFIX_INCREMENT(type) \
celestar@5650: 	FORCEINLINE type operator ++(type& e, int) \
celestar@5650: 	{ \
celestar@5650: 		type e_org = e; \
celestar@5650: 		e = (type)((int)e + 1); \
celestar@5650: 		return e_org; \
celestar@5650: 	} \
celestar@5650: 	FORCEINLINE type operator --(type& e, int) \
celestar@5650: 	{ \
celestar@5650: 		type e_org = e; \
celestar@5650: 		e = (type)((int)e - 1); \
celestar@5650: 		return e_org; \
celestar@5650: 	}
celestar@5650: 
celestar@5650: 
celestar@5650: 
celestar@5650: /** Operators to allow to work with enum as with type safe bit set in C++ */
celestar@5650: # define DECLARE_ENUM_AS_BIT_SET(mask_t) \
celestar@5650: 	FORCEINLINE mask_t operator | (mask_t m1, mask_t m2) {return (mask_t)((int)m1 | m2);} \
celestar@5650: 	FORCEINLINE mask_t operator & (mask_t m1, mask_t m2) {return (mask_t)((int)m1 & m2);} \
celestar@5650: 	FORCEINLINE mask_t operator ^ (mask_t m1, mask_t m2) {return (mask_t)((int)m1 ^ m2);} \
celestar@5650: 	FORCEINLINE mask_t& operator |= (mask_t& m1, mask_t m2) {m1 = m1 | m2; return m1;} \
celestar@5650: 	FORCEINLINE mask_t& operator &= (mask_t& m1, mask_t m2) {m1 = m1 & m2; return m1;} \
celestar@5650: 	FORCEINLINE mask_t& operator ^= (mask_t& m1, mask_t m2) {m1 = m1 ^ m2; return m1;} \
celestar@5650: 	FORCEINLINE mask_t operator ~(mask_t m) {return (mask_t)(~(int)m);}
celestar@5650: 
celestar@5650: /** probably redundant enum combining operators (as we have conversion functions)
celestar@5650:  *  but the old code is full of such arithmetics */
celestar@5650: # define DECLARE_ENUM_AS_BIT_INDEX(idx_t, mask_t) \
celestar@5650: 	FORCEINLINE mask_t operator << (int m, idx_t i) {return (mask_t)(m << (int)i);} \
celestar@5650: 	FORCEINLINE mask_t operator << (mask_t m, int i) {return (mask_t)(((int)m) << i);} \
celestar@5650: 	FORCEINLINE mask_t operator >> (mask_t m, int i) {return (mask_t)(((int)m) >> i);}
celestar@5650: 
celestar@5650: 
celestar@5650: /** Informative template class exposing basic enumeration properties used by several
celestar@5650:  *  other templates below. Here we have only forward declaration. For each enum type
celestar@5650:  *  we will create specialization derived from MakeEnumPropsT<>. */
celestar@5650: template <typename Tenum_t> struct EnumPropsT;
celestar@5650: 
celestar@5650: /** Helper template class that makes basic properties of given enumeration type visible
celestar@5650:  *  from outsize. It is used as base class of several EnumPropsT specializations each
celestar@5650:  *  dedicated to one of commonly used enumeration types. */
celestar@5650: template <typename Tenum_t, typename Tstorage_t, Tenum_t Tbegin, Tenum_t Tend, Tenum_t Tinvalid>
celestar@5650: struct MakeEnumPropsT {
celestar@5650: 	typedef Tenum_t type;                     ///< enum type (i.e. Trackdir)
celestar@5650: 	typedef Tstorage_t storage;               ///< storage type (i.e. byte)
celestar@5650: 	static const Tenum_t begin = Tbegin;      ///< lowest valid value (i.e. TRACKDIR_BEGIN)
celestar@5650: 	static const Tenum_t end = Tend;          ///< one after the last valid value (i.e. TRACKDIR_END)
celestar@5650: 	static const Tenum_t invalid = Tinvalid;  ///< what value is used as invalid value (i.e. INVALID_TRACKDIR)
celestar@5650: };
celestar@5650: 
celestar@5650: 
celestar@5650: 
celestar@5650: /** In some cases we use byte or uint16 to store values that are defined as enum. It is
celestar@5650: 	*  necessary in order to control the sizeof() such values. Some compilers make enum
celestar@5650: 	*  the same size as int (4 or 8 bytes instead of 1 or 2). As a consequence the strict
celestar@5650: 	*  compiler type-checking causes errors like:
celestar@5650: 	*     'HasPowerOnRail' : cannot convert parameter 1 from 'byte' to 'RailType' when
celestar@5650: 	*  u->u.rail.railtype is passed as argument or type RailType. In such cases it is better
celestar@5650: 	*  to teach the compiler that u->u.rail.railtype is to be treated as RailType. */
celestar@5650: template <typename Tenum_t> struct TinyEnumT;
celestar@5650: 
celestar@5650: /** The general declaration of TinyEnumT<> (above) */
celestar@5650: template <typename Tenum_t> struct TinyEnumT
celestar@5650: {
celestar@5650: 	typedef Tenum_t enum_type;                      ///< expose our enumeration type (i.e. Trackdir) to outside
celestar@5650: 	typedef EnumPropsT<Tenum_t> Props;              ///< make easier access to our enumeration propeties
celestar@5650: 	typedef typename Props::storage storage_type;   ///< small storage type
celestar@5650: 	static const enum_type begin = Props::begin;    ///< enum beginning (i.e. TRACKDIR_BEGIN)
celestar@5650: 	static const enum_type end = Props::end;        ///< enum end (i.e. TRACKDIR_END)
celestar@5650: 	static const enum_type invalid = Props::invalid;///< invalid value (i.e. INVALID_TRACKDIR)
celestar@5650: 
celestar@5650: 	storage_type m_val;  ///< here we hold the actual value in small (i.e. byte) form
celestar@5650: 
celestar@5650: 	/** Cast operator - invoked then the value is assigned to the Tenum_t type */
celestar@5650: 	FORCEINLINE operator enum_type () const
celestar@5650: 	{
celestar@5650: 		return (enum_type)m_val;
celestar@5650: 	}
celestar@5650: 
celestar@5650: 	/** Assignment operator (from Tenum_t type) */
celestar@5650: 	FORCEINLINE TinyEnumT& operator = (enum_type e)
celestar@5650: 	{
celestar@5650: 		m_val = (storage_type)e; return *this;
celestar@5650: 	}
celestar@5650: 
celestar@5650: 	/** postfix ++ operator on tiny type */
celestar@5650: 	FORCEINLINE TinyEnumT& operator ++ (int)
celestar@5650: 	{
celestar@5650: 		if (++m_val >= end) m_val -= (storage_type)(end - begin);
celestar@5650: 		return *this;
celestar@5650: 	}
celestar@5650: };
celestar@5650: 
celestar@5650: template <typename Tenum_t> FORCEINLINE void SwapT(TinyEnumT<Tenum_t> *a, TinyEnumT<Tenum_t> *b)
celestar@5650: {
celestar@5650: 	SwapT(&a->m_val, &b->m_val);
celestar@5650: }
celestar@5650: 
celestar@5650: template <typename T> FORCEINLINE T ClrBitT(T t, int bit_index)
celestar@5650: {
celestar@5650: 	int val = t;
celestar@5650: 	CLRBIT(val, bit_index);
celestar@5650: 	return (T)val;
celestar@5650: }
celestar@5650: 
celestar@5650: template <typename T> FORCEINLINE T SetBitT(T t, int bit_index)
celestar@5650: {
celestar@5650: 	int val = t;
celestar@5650: 	SETBIT(val, bit_index);
celestar@5650: 	return (T)val;
celestar@5650: }
celestar@5650: 
celestar@5650: template <typename T> FORCEINLINE T ToggleBitT(T t, int bit_index)
celestar@5650: {
celestar@5650: 	int val = t;
celestar@5650: 	TOGGLEBIT(val, bit_index);
celestar@5650: 	return (T)val;
celestar@5650: }
celestar@5650: 
celestar@5650: #else // __cplusplus
celestar@5650: 
celestar@5650: #define DECLARE_POSTFIX_INCREMENT(E)
celestar@5650: #define DECLARE_ENUM_AS_BIT_SET(E)
celestar@5650: #define DECLARE_ENUM_AS_BIT_INDEX(E1,E2)
celestar@5650: 
celestar@5650: #endif  // __cplusplus
celestar@5650: 
celestar@5650: #endif /* HELPERS_HPP */