diff options
Diffstat (limited to 'src/macros.h')
| -rw-r--r-- | src/macros.h | 269 |
1 files changed, 1 insertions, 268 deletions
diff --git a/src/macros.h b/src/macros.h index bbe574cf5..51329ab19 100644 --- a/src/macros.h +++ b/src/macros.h @@ -5,176 +5,9 @@ #ifndef MACROS_H #define MACROS_H +#include "core/bitmath_func.hpp" #include "core/math_func.hpp" -/** - * Fetch n bits from x, started at bit s. - * - * This function can be used to fetch n bits from the value x. The - * s value set the startposition to read. The startposition is - * count from the LSB and starts at 0. The result starts at a - * LSB, as this isn't just an and-bitmask but also some - * bit-shifting operations. GB(0xFF, 2, 1) will so - * return 0x01 (0000 0001) instead of - * 0x04 (0000 0100). - * - * @param x The value to read some bits. - * @param s The startposition to read some bits. - * @param n The number of bits to read. - * @return The selected bits, aligned to a LSB. - */ -template<typename T> static inline uint GB(const T x, const uint8 s, const uint8 n) -{ - return (x >> s) & ((1U << n) - 1); -} - -/** Set n bits from x starting at bit s to d - * - * This function sets n bits from x which started as bit s to the value of - * d. The parameters x, s and n works the same as the parameters of - * #GB. The result is saved in x again. Unused bits in the window - * provided by n are set to 0 if the value of b isn't "big" enough. - * This is not a bug, its a feature. - * - * @note Parameter x must be a variable as the result is saved there. - * @note To avoid unexpecting results the value of b should not use more - * space as the provided space of n bits (log2) - * @param x The variable to change some bits - * @param s The startposition for the new bits - * @param n The size/window for the new bits - * @param d The actually new bits to save in the defined position. - * @return The new value of x - */ -template<typename T, typename U> static inline T SB(T& x, const uint8 s, const uint8 n, const U d) -{ - x &= (T)(~(((1U << n) - 1) << s)); - x |= (T)(d << s); - return x; -} - -/** Add i to n bits of x starting at bit s. - * - * This add the value of i on n bits of x starting at bit s. The parameters x, - * s, i are similar to #GB besides x must be a variable as the result are - * saved there. An overflow does not affect the following bits of the given - * bit window and is simply ignored. - * - * @note Parameter x must be a variable as the result is saved there. - * @param x The variable to add some bits at some position - * @param s The startposition of the addition - * @param n The size/window for the addition - * @param i The value to add at the given startposition in the given window. - * @return The new value of x - */ -template<typename T, typename U> static inline T AB(T& x, const uint8 s, const uint8 n, const U i) -{ - const T mask = (T)(((1U << n) - 1) << s); - x = (T)((x & ~mask) | ((x + (i << s)) & mask)); - return x; -} - -/** - * Checks if a bit in a value is set. - * - * This function checks if a bit inside a value is set or not. - * The y value specific the position of the bit, started at the - * LSB and count from 0. - * - * @param x The value to check - * @param y The position of the bit to check, started from the LSB - * @return True if the bit is set, false else. - */ -template<typename T> static inline bool HasBit(const T x, const uint8 y) -{ - return (x & ((T)1U << y)) != 0; -} - -/** - * Set a bit in a variable. - * - * This function sets a bit in a variable. The variable is changed - * and the value is also returned. Parameter y defines the bit and - * starts at the LSB with 0. - * - * @param x The variable to set a bit - * @param y The bit position to set - * @return The new value of the old value with the bit set - */ -template<typename T> static inline T SetBit(T& x, const uint8 y) -{ - return x = (T)(x | (T)(1U << y)); -} - -/** - * Clears a bit in a variable. - * - * This function clears a bit in a variable. The variable is - * changed and the value is also returned. Parameter y defines the bit - * to clear and starts at the LSB with 0. - * - * @param x The variable to clear the bit - * @param y The bit position to clear - * @return The new value of the old value with the bit cleared - */ -template<typename T> static inline T ClrBit(T& x, const uint8 y) -{ - return x = (T)(x & ~((T)1U << y)); -} - -/** - * Toggles a bit in a variable. - * - * This function toggles a bit in a variable. The variable is - * changed and the value is also returned. Parameter y defines the bit - * to toggle and starts at the LSB with 0. - * - * @param x The varliable to toggle the bit - * @param y The bit position to toggle - * @return The new value of the old value with the bit toggled - */ -template<typename T> static inline T ToggleBit(T& x, const uint8 y) -{ - return x = (T)(x ^ (T)(1U << y)); -} - - -/* checking more bits. Maybe unneccessary, but easy to use */ -/** - * Check several bits in a value. - * - * This macro checks if a value contains at least one bit of an other - * value. - * - * @param x The first value - * @param y The second value - * @return True if at least one bit is set in both values, false else. - */ -#define HASBITS(x, y) ((x) & (y)) - -/** - * Sets several bits in a variable. - * - * This macro sets several bits in a variable. The bits to set are provided - * by a value. The new value is also returned. - * - * @param x The variable to set some bits - * @param y The value with set bits for setting them in the variable - * @return The new value of x - */ -#define SETBITS(x, y) ((x) |= (y)) - -/** - * Clears several bits in a variable. - * - * This macro clears several bits in a variable. The bits to clear are - * provided by a value. The new value is also returned. - * - * @param x The variable to clear some bits - * @param y The value with set bits for clearing them in the variable - * @return The new value of x - */ -#define CLRBITS(x, y) ((x) &= ~(y)) - #define GENERAL_SPRITE_COLOR(color) ((color) + PALETTE_RECOLOR_START) #define PLAYER_SPRITE_COLOR(owner) (GENERAL_SPRITE_COLOR(_player_colors[owner])) @@ -187,80 +20,6 @@ template<typename T> static inline T ToggleBit(T& x, const uint8 y) */ #define IS_CUSTOM_SPRITE(sprite) ((sprite) >= SPR_SIGNALS_BASE) -extern const byte _ffb_64[64]; - -/** - * Returns the first occure of a bit in a 6-bit value (from right). - * - * Returns the position of the first bit that is not zero, counted from the - * LSB. Ie, 110100 returns 2, 000001 returns 0, etc. When x == 0 returns - * 0. - * - * @param x The 6-bit value to check the first zero-bit - * @return The first position of a bit started from the LSB or 0 if x is 0. - */ -#define FIND_FIRST_BIT(x) _ffb_64[(x)] - -/** - * Finds the position of the first bit in an integer. - * - * This function returns the position of the first bit set in the - * integer. It does only check the bits of the bitmask - * 0x3F3F (0011111100111111) and checks only the - * bits of the bitmask 0x3F00 if and only if the - * lower part 0x00FF is 0. This results the bits at 0x00C0 must - * be also zero to check the bits at 0x3F00. - * - * @param value The value to check the first bits - * @return The position of the first bit which is set - * @see FIND_FIRST_BIT - */ -static inline int FindFirstBit2x64(int value) -{ - if ((value & 0xFF) == 0) { - return FIND_FIRST_BIT((value >> 8) & 0x3F) + 8; - } else { - return FIND_FIRST_BIT(value & 0x3F); - } -} - -/** - * Clear the first bit in an integer. - * - * This function returns a value where the first bit (from LSB) - * is cleared. - * So, 110100 returns 110000, 000001 returns 000000, etc. - * - * @param value The value to clear the first bit - * @return The new value with the first bit cleared - */ -template<typename T> static inline T KillFirstBit(T value) -{ - return value &= (T)(value - 1); -} - -/** - * Counts the number of set bits in a variable. - * - * @param value the value to count the number of bits in. - * @return the number of bits. - */ -template<typename T> static inline uint CountBits(T value) -{ - uint num; - - /* This loop is only called once for every bit set by clearing the lowest - * bit in each loop. The number of bits is therefore equal to the number of - * times the loop was called. It was found at the following website: - * http://graphics.stanford.edu/~seander/bithacks.html */ - - for (num = 0; value != 0; num++) { - value &= (T)(value - 1); - } - - return num; -} - #define for_each_bit(_i, _b) \ for (_i = 0; _b != 0; _i++, _b >>= 1) \ @@ -282,32 +41,6 @@ static inline uint16 ReadLE16Unaligned(const void* x) } -/** - * ROtate x Left by n - * - * @note Assumes a byte has 8 bits - * @param x The value which we want to rotate - * @param n The number how many we waht to rotate - * @return A bit rotated number - */ -template<typename T> static inline T ROL(const T x, const uint8 n) -{ - return (T)(x << n | x >> (sizeof(x) * 8 - n)); -} - -/** - * ROtate x Right by n - * - * @note Assumes a byte has 8 bits - * @param x The value which we want to rotate - * @param n The number how many we waht to rotate - * @return A bit rotated number - */ -template<typename T> static inline T ROR(const T x, const uint8 n) -{ - return (T)(x >> n | x << (sizeof(x) * 8 - n)); -} - /** return the largest value that can be entered in a variable. */ #define MAX_UVALUE(type) ((type)~(type)0) |