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author | rubidium <rubidium@openttd.org> | 2007-01-10 18:56:51 +0000 |
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committer | rubidium <rubidium@openttd.org> | 2007-01-10 18:56:51 +0000 |
commit | f35ed4bbc2b05f1b83476b60948d64375f77f1b4 (patch) | |
tree | 1a1c59c13ddb1d152052f3a3a0bcffe4fb531173 /src/helpers.hpp | |
parent | a332d10fd938f345fff18e5f4a662a58f692f734 (diff) | |
download | openttd-f35ed4bbc2b05f1b83476b60948d64375f77f1b4.tar.xz |
(svn r8038) -Merge: the cpp branch. Effort of KUDr, Celestar, glx, Smoovius, stillunknown and pv2b.
Diffstat (limited to 'src/helpers.hpp')
-rw-r--r-- | src/helpers.hpp | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/src/helpers.hpp b/src/helpers.hpp new file mode 100644 index 000000000..b13fc25d4 --- /dev/null +++ b/src/helpers.hpp @@ -0,0 +1,178 @@ +/* $Id$ */ + +#ifndef HELPERS_HPP +#define HELPERS_HPP + +/** @file helpers.hpp */ +#include "macros.h" + +#ifdef __cplusplus + +/** When allocating using malloc/calloc in C++ it is usually needed to cast the return value +* from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ +template <typename T> FORCEINLINE bool MallocT(T** t_ptr, size_t num_elements) +{ + *t_ptr = (T*)malloc(num_elements * sizeof(T)); + return (*t_ptr != NULL); +} +/** When allocating using malloc/calloc in C++ it is usually needed to cast the return value +* from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ +template <typename T> FORCEINLINE bool CallocT(T** t_ptr, size_t num_elements) +{ + *t_ptr = (T*)calloc(num_elements, sizeof(T)); + return (*t_ptr != NULL); +} +/** When allocating using malloc/calloc in C++ it is usually needed to cast the return value +* from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ +template <typename T> FORCEINLINE bool ReallocT(T** t_ptr, size_t num_elements) +{ + *t_ptr = (T*)realloc(*t_ptr, num_elements * sizeof(T)); + return (*t_ptr != NULL); +} + +/** type safe swap operation */ +template <typename T> void SwapT(T *a, T *b); + +template <typename T> FORCEINLINE void SwapT(T *a, T *b) +{ + T t = *a; + *a = *b; + *b = t; +} + + +/** returns the absolute value of (scalar) variable. @note assumes variable to be signed */ +template <typename T> static inline T myabs(T a) { return a < (T)0 ? -a : a; } +/** returns the (absolute) difference between two (scalar) variables */ +template <typename T> static inline T delta(T a, T b) { return a < b ? b - a : a - b; } + +/** Some enums need to have allowed incrementing (i.e. StationClassID) */ +#define DECLARE_POSTFIX_INCREMENT(type) \ + FORCEINLINE type operator ++(type& e, int) \ + { \ + type e_org = e; \ + e = (type)((int)e + 1); \ + return e_org; \ + } \ + FORCEINLINE type operator --(type& e, int) \ + { \ + type e_org = e; \ + e = (type)((int)e - 1); \ + return e_org; \ + } + + + +/** Operators to allow to work with enum as with type safe bit set in C++ */ +# define DECLARE_ENUM_AS_BIT_SET(mask_t) \ + FORCEINLINE mask_t operator | (mask_t m1, mask_t m2) {return (mask_t)((int)m1 | m2);} \ + FORCEINLINE mask_t operator & (mask_t m1, mask_t m2) {return (mask_t)((int)m1 & m2);} \ + FORCEINLINE mask_t operator ^ (mask_t m1, mask_t m2) {return (mask_t)((int)m1 ^ m2);} \ + FORCEINLINE mask_t& operator |= (mask_t& m1, mask_t m2) {m1 = m1 | m2; return m1;} \ + FORCEINLINE mask_t& operator &= (mask_t& m1, mask_t m2) {m1 = m1 & m2; return m1;} \ + FORCEINLINE mask_t& operator ^= (mask_t& m1, mask_t m2) {m1 = m1 ^ m2; return m1;} \ + FORCEINLINE mask_t operator ~(mask_t m) {return (mask_t)(~(int)m);} + +/** probably redundant enum combining operators (as we have conversion functions) + * but the old code is full of such arithmetics */ +# define DECLARE_ENUM_AS_BIT_INDEX(idx_t, mask_t) \ + FORCEINLINE mask_t operator << (int m, idx_t i) {return (mask_t)(m << (int)i);} \ + FORCEINLINE mask_t operator << (mask_t m, int i) {return (mask_t)(((int)m) << i);} \ + FORCEINLINE mask_t operator >> (mask_t m, int i) {return (mask_t)(((int)m) >> i);} + + +/** Informative template class exposing basic enumeration properties used by several + * other templates below. Here we have only forward declaration. For each enum type + * we will create specialization derived from MakeEnumPropsT<>. */ +template <typename Tenum_t> struct EnumPropsT; + +/** Helper template class that makes basic properties of given enumeration type visible + * from outsize. It is used as base class of several EnumPropsT specializations each + * dedicated to one of commonly used enumeration types. */ +template <typename Tenum_t, typename Tstorage_t, Tenum_t Tbegin, Tenum_t Tend, Tenum_t Tinvalid> +struct MakeEnumPropsT { + typedef Tenum_t type; ///< enum type (i.e. Trackdir) + typedef Tstorage_t storage; ///< storage type (i.e. byte) + static const Tenum_t begin = Tbegin; ///< lowest valid value (i.e. TRACKDIR_BEGIN) + static const Tenum_t end = Tend; ///< one after the last valid value (i.e. TRACKDIR_END) + static const Tenum_t invalid = Tinvalid; ///< what value is used as invalid value (i.e. INVALID_TRACKDIR) +}; + + + +/** In some cases we use byte or uint16 to store values that are defined as enum. It is + * necessary in order to control the sizeof() such values. Some compilers make enum + * the same size as int (4 or 8 bytes instead of 1 or 2). As a consequence the strict + * compiler type-checking causes errors like: + * 'HasPowerOnRail' : cannot convert parameter 1 from 'byte' to 'RailType' when + * u->u.rail.railtype is passed as argument or type RailType. In such cases it is better + * to teach the compiler that u->u.rail.railtype is to be treated as RailType. */ +template <typename Tenum_t> struct TinyEnumT; + +/** The general declaration of TinyEnumT<> (above) */ +template <typename Tenum_t> struct TinyEnumT +{ + typedef Tenum_t enum_type; ///< expose our enumeration type (i.e. Trackdir) to outside + typedef EnumPropsT<Tenum_t> Props; ///< make easier access to our enumeration propeties + typedef typename Props::storage storage_type; ///< small storage type + static const enum_type begin = Props::begin; ///< enum beginning (i.e. TRACKDIR_BEGIN) + static const enum_type end = Props::end; ///< enum end (i.e. TRACKDIR_END) + static const enum_type invalid = Props::invalid;///< invalid value (i.e. INVALID_TRACKDIR) + + storage_type m_val; ///< here we hold the actual value in small (i.e. byte) form + + /** Cast operator - invoked then the value is assigned to the Tenum_t type */ + FORCEINLINE operator enum_type () const + { + return (enum_type)m_val; + } + + /** Assignment operator (from Tenum_t type) */ + FORCEINLINE TinyEnumT& operator = (enum_type e) + { + m_val = (storage_type)e; return *this; + } + + /** postfix ++ operator on tiny type */ + FORCEINLINE TinyEnumT& operator ++ (int) + { + if (++m_val >= end) m_val -= (storage_type)(end - begin); + return *this; + } +}; + +template <typename Tenum_t> FORCEINLINE void SwapT(TinyEnumT<Tenum_t> *a, TinyEnumT<Tenum_t> *b) +{ + SwapT(&a->m_val, &b->m_val); +} + +template <typename T> FORCEINLINE T ClrBitT(T t, int bit_index) +{ + int val = t; + CLRBIT(val, bit_index); + return (T)val; +} + +template <typename T> FORCEINLINE T SetBitT(T t, int bit_index) +{ + int val = t; + SETBIT(val, bit_index); + return (T)val; +} + +template <typename T> FORCEINLINE T ToggleBitT(T t, int bit_index) +{ + int val = t; + TOGGLEBIT(val, bit_index); + return (T)val; +} + +#else // __cplusplus + +#define DECLARE_POSTFIX_INCREMENT(E) +#define DECLARE_ENUM_AS_BIT_SET(E) +#define DECLARE_ENUM_AS_BIT_INDEX(E1,E2) + +#endif // __cplusplus + +#endif /* HELPERS_HPP */ |