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/* $Id$ */

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/** @file macros.h */

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#ifndef MACROS_H

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#define MACROS_H

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/* Fetch n bits starting at bit s from x */

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#define GB(x, s, n) (((x) >> (s)) & ((1U << (n)) - 1))

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/* Set n bits starting at bit s in x to d */

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#define SB(x, s, n, d) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | ((d) << (s)))

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/* Add i to the n bits starting at bit s in x */

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#define AB(x, s, n, i) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | (((x) + ((i) << (s))) & (((1U << (n)) - 1) << (s))))

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#ifdef min

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#undef min

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#endif

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#ifdef max

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#undef max

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#endif

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template <typename T>

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static inline T max(T a, T b)

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{

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	return a >= b ? a : b;

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}

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template <typename T>

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static inline T min(T a, T b)

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{

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	return a < b ? a : b;

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}

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static inline int min(int a, int b) { if (a <= b) return a; return b; }

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static inline uint minu(uint a, uint b) { if (a <= b) return a; return b; }

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static inline int clamp(int a, int min, int max)

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{

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	if (a <= min) return min;

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	if (a >= max) return max;

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	return a;

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}

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static inline uint clampu(uint a, uint min, uint max)

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{

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	if (a <= min) return min;

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	if (a >= max) return max;

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	return a;

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}

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/* Gracefully reduce a signed 64-bit int to signed 32-bit -- no bogusly truncating the sign bit */

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static inline int32 ClampToI32(int64 a)

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{

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	if (a <= (int32)0x80000000) return 0x80000000;

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	if (a >= (int32)0x7FFFFFFF) return 0x7FFFFFFF;

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	return (int32)a;

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}

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static inline int32 BIGMULSS(int32 a, int32 b, int shift)

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{

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	return (int32)((int64)a * (int64)b >> shift);

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}

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static inline uint32 BIGMULUS(uint32 a, uint32 b, int shift)

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{

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	return (uint32)((uint64)a * (uint64)b >> shift);

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}

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/* OPT: optimized into an unsigned comparison */

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//#define IS_INSIDE_1D(x, base, size) ((x) >= (base) && (x) < (base) + (size))

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#define IS_INSIDE_1D(x, base, size) ( (uint)((x) - (base)) < ((uint)(size)) )

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template<typename T> static inline bool HASBIT(T x, int y)

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{

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	return (x & ((T)1 << y)) != 0;

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}

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template<typename T> static inline T SETBIT(T& x, int y)

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{

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	return x |= (T)1 << y;

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}

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template<typename T> static inline T CLRBIT(T& x, int y)

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{

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	return x &= ~((T)1 << y);

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}

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template<typename T> static inline T TOGGLEBIT(T& x, int y)

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{

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	return x ^= (T)1 << y;

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}

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/* checking more bits. Maybe unneccessary, but easy to use */

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#define HASBITS(x, y) ((x) & (y))

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#define SETBITS(x, y) ((x) |= (y))

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#define CLRBITS(x, y) ((x) &= ~(y))

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#define GENERAL_SPRITE_COLOR(color) ((color) + PALETTE_RECOLOR_START)

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#define PLAYER_SPRITE_COLOR(owner) (GENERAL_SPRITE_COLOR(_player_colors[owner]))

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extern const byte _ffb_64[128];

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/* Returns the position of the first bit that is not zero, counted from the

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 * left. Ie, 10110100 returns 2, 00000001 returns 0, etc. When x == 0 returns

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 * 0.

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 */

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#define FIND_FIRST_BIT(x) _ffb_64[(x)]

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/* Returns x with the first bit that is not zero, counted from the left, set

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 * to zero. So, 10110100 returns 10110000, 00000001 returns 00000000, etc.

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 */

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#define KILL_FIRST_BIT(x) _ffb_64[(x) + 64]

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static inline int FindFirstBit2x64(int value)

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{

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/*

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	int i = 0;

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	if ( (byte) value == 0) {

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		i += 8;

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		value >>= 8;

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	}

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	return i + FIND_FIRST_BIT(value & 0x3F);

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Faster ( or at least cleaner ) implementation below?

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*/

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	if (GB(value, 0, 8) == 0) {

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		return FIND_FIRST_BIT(GB(value, 8, 6)) + 8;

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	} else {

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		return FIND_FIRST_BIT(GB(value, 0, 6));

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	}

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}

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static inline int KillFirstBit2x64(int value)

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{

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	if (GB(value, 0, 8) == 0) {

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		return KILL_FIRST_BIT(GB(value, 8, 6)) << 8;

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	} else {

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		return value & (KILL_FIRST_BIT(GB(value, 0, 6)) | 0x3F00);

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	}

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}

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/** returns true if value a has only one bit set to 1 */

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#define HAS_SINGLE_BIT(a) ( ((a) & ((a) - 1)) == 0)

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/* [min,max), strictly less than */

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#define IS_BYTE_INSIDE(a, min, max) ((byte)((a) - (min)) < (byte)((max) - (min)))

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#define IS_INT_INSIDE(a, min, max) ((uint)((a) - (min)) < (uint)((max) - (min)))

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#define CHANCE16(a, b) ((uint16)Random() <= (uint16)((65536 * (a)) / (b)))

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#define CHANCE16R(a, b, r) ((uint16)(r = Random()) <= (uint16)((65536 * (a)) / (b)))

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#define CHANCE16I(a, b, v) ((uint16)(v) <= (uint16)((65536 * (a)) / (b)))

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#define for_each_bit(_i, _b)            \

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	for (_i = 0; _b != 0; _i++, _b >>= 1) \

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		if (_b & 1)

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#define abs myabs

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static inline uint16 ReadLE16Aligned(const void* x)

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{

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	return FROM_LE16(*(const uint16*)x);

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}

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static inline uint16 ReadLE16Unaligned(const void* x)

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{

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#ifdef OTTD_ALIGNMENT

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	return ((const byte*)x)[0] | ((const byte*)x)[1] << 8;

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#else

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	return FROM_LE16(*(const uint16*)x);

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#endif

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}

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/**

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 * ROtate x Left/Right by n (must be >= 0)

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 * @note Assumes a byte has 8 bits

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 */

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#define ROL(x, n) ((x) << (n) | (x) >> (sizeof(x) * 8 - (n)))

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#define ROR(x, n) ((x) >> (n) | (x) << (sizeof(x) * 8 - (n)))

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/**

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 * Return the smallest multiple of n equal or greater than x

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 * @note n must be a power of 2

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 */

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#define ALIGN(x, n) (((x) + (n) - 1) & ~((n) - 1))

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/** return the largest value that can be entered in a variable.

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 */

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#define MAX_UVALUE(type) ((type)~(type)0)

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#endif /* MACROS_H */