(svn r10689) -Documentation [FS#1057]: lots of function documentation written by Progman.

1 files changed, 351 insertions, 13 deletions

diff --git a/src/macros.h b/src/macros.h
index 406ae83da..e7944661a 100644
--- a/src/macros.h
+++ b/src/macros.h
@@ -5,11 +5,57 @@
 #ifndef MACROS_H
 #define MACROS_H
 
-/* Fetch n bits starting at bit s from x */
+/**
+ * Fetch n bits from x, started at bit s.
+ *
+ * This macro 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.
+ */
 #define GB(x, s, n) (((x) >> (s)) & ((1U << (n)) - 1))
-/* Set n bits starting at bit s in x to d */
+
+/** Set n bits from x starting at bit s to d
+ *
+ * This macro 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
+ */
 #define SB(x, s, n, d) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | ((d) << (s)))
-/* Add i to the n bits starting at bit s in 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
+ */
 #define AB(x, s, n, i) ((x) = ((x) & ~(((1U << (n)) - 1) << (s))) | (((x) + ((i) << (s))) & (((1U << (n)) - 1) << (s))))
 
 #ifdef min
@@ -20,23 +66,76 @@
 #undef max
 #endif
 
+/**
+ * Returns the maximum of two values.
+ *
+ * This function returns the greater value of two given values.
+ * If they are equal the value of a is returned.
+ *
+ * @param a The first value
+ * @param b The second value
+ * @return The greater value or a if equals
+ */
 template <typename T>
 static inline T max(T a, T b)
 {
 	return a >= b ? a : b;
 }
 
+/**
+ * Returns the minimum of two values.
+ *
+ * This function returns the smaller value of two given values.
+ * If they are equal the value of b is returned.
+ *
+ * @param a The first value
+ * @param b The second value
+ * @return The smaller value or b if equals
+ */
 template <typename T>
 static inline T min(T a, T b)
 {
 	return a < b ? a : b;
 }
 
+/**
+ * Returns the minimum of two integer.
+ *
+ * This function returns the smaller value of two given integers.
+ *
+ * @param a The first integer
+ * @param b The second integer
+ * @return The smaller value
+ */
 static inline int min(int a, int b) { if (a <= b) return a; return b; }
 
+/**
+ * Returns the minimum of two unsigned integers.
+ *
+ * This function returns the smaller value of two given unsigned integers.
+ *
+ * @param a The first unsigned integer
+ * @param b The second unsigned integer
+ * @return The smaller value
+ */
 static inline uint minu(uint a, uint b) { if (a <= b) return a; return b; }
 
-
+/**
+ * Clamp an integer between an interval.
+ *
+ * This function returns a value which is between the given interval of
+ * min and max. If the given value is in this interval the value itself
+ * is returned otherwise the border of the interval is returned, according
+ * which side of the interval was 'left'.
+ *
+ * @note The min value must be less or equal of max or you get some
+ *       unexpected results.
+ * @param a The value to clamp/truncate.
+ * @param min The minimum of the interval.
+ * @param max the maximum of the interval.
+ * @returns A value between min and max which is closest to a.
+ * @see clampu(uint, uint, uint)
+ */
 static inline int clamp(int a, int min, int max)
 {
 	if (a <= min) return min;
@@ -44,6 +143,22 @@ static inline int clamp(int a, int min, int max)
 	return a;
 }
 
+/**
+ * Clamp an unsigned integer between an interval.
+ *
+ * This function returns a value which is between the given interval of
+ * min and max. If the given value is in this interval the value itself
+ * is returned otherwise the border of the interval is returned, according
+ * which side of the interval was 'left'.
+ *
+ * @note The min value must be less or equal of max or you get some
+ *       unexpected results.
+ * @param a The value to clamp/truncate.
+ * @param min The minimum of the interval.
+ * @param max the maximum of the interval.
+ * @returns A value between min and max which is closest to a.
+ * @see clamp(int, int, int)
+ */
 static inline uint clampu(uint a, uint min, uint max)
 {
 	if (a <= min) return min;
@@ -51,7 +166,20 @@ static inline uint clampu(uint a, uint min, uint max)
 	return a;
 }
 
-/* Gracefully reduce a signed 64-bit int to signed 32-bit -- no bogusly truncating the sign bit */
+/**
+ * Reduce a signed 64-bit int to a signed 32-bit one
+ *
+ * This function clamps a 64-bit integer to a 32-bit integer.
+ * If the 64-bit value is smaller than the smallest 32-bit integer
+ * value 0x80000000 this value is returned (the left one bit is the sign bit).
+ * If the 64-bit value is greater than the greatest 32-bit integer value 0x7FFFFFFF
+ * this value is returned. In all other cases the 64-bit value 'fits' in a
+ * 32-bits integer field and so the value is casted to int32 and returned.
+ *
+ * @param a The 64-bit value to clamps
+ * @return The 64-bit value reduced to a 32-bit value
+ * @see clamp(int, int, int)
+ */
 static inline int32 ClampToI32(int64 a)
 {
 	if (a <= (int32)0x80000000) return 0x80000000;
@@ -59,36 +187,114 @@ static inline int32 ClampToI32(int64 a)
 	return (int32)a;
 }
 
+/**
+ * Multiply two integer values and shift the results to right.
+ *
+ * This function multiplies two integer values. The result is
+ * shifted by the amount of shift to right.
+ *
+ * @param a The first integer
+ * @param b The second integer
+ * @param shift The amount to shift the value to right.
+ * @return The shifted result
+ */
 static inline int32 BIGMULSS(int32 a, int32 b, int shift)
 {
 	return (int32)((int64)a * (int64)b >> shift);
 }
 
+/**
+ * Multiply two unsigned integers and shift the results to right.
+ *
+ * This function multiplies two unsigned integers. The result is
+ * shifted by the amount of shift to right.
+ *
+ * @param a The first unsigned integer
+ * @param b The second unsigned integer
+ * @param shift The amount to shift the value to right.
+ * @return The shifted result
+ */
 static inline uint32 BIGMULUS(uint32 a, uint32 b, int shift)
 {
 	return (uint32)((uint64)a * (uint64)b >> shift);
 }
 
 
+/**
+ * Checks if a value is between a window started at some base point.
+ *
+ * This macro checks if the value x is between the value of base
+ * and base+size. If x equals base this returns true. If x equals
+ * base+size this returns false.
+ *
+ * @param x The value to check
+ * @param base The base value of the interval
+ * @param size The size of the interval
+ * @return True if the value is in the interval, false else.
+ */
 /* OPT: optimized into an unsigned comparison */
 //#define IS_INSIDE_1D(x, base, size) ((x) >= (base) && (x) < (base) + (size))
 #define IS_INSIDE_1D(x, base, size) ( (uint)((x) - (base)) < ((uint)(size)) )
 
+/**
+ * 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(T x, int y)
 {
 	return (x & ((T)1 << 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, int y)
 {
 	return x |= (T)1 << 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, int y)
 {
 	return x &= ~((T)1 << 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, int y)
 {
 	return x ^= (T)1 << y;
@@ -96,24 +302,84 @@ template<typename T> static inline T TOGGLEBIT(T& x, int 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]))
 
 extern const byte _ffb_64[128];
-/* Returns the position of the first bit that is not zero, counted from the
- * left. Ie, 10110100 returns 2, 00000001 returns 0, etc. When x == 0 returns
+
+/**
+ * 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)]
-/* Returns x with the first bit that is not zero, counted from the left, set
- * to zero. So, 10110100 returns 10110000, 00000001 returns 00000000, etc.
+
+/**
+ * Returns a value with the first occured of a bit set to zero.
+ *
+ * Returns x with the first bit from LSB that is not zero set
+ * to zero. So, 110100 returns 110000, 000001 returns 000000, etc.
+ *
+ * @param x The value to returned a new value
+ * @return The value which the first bit is set to zero
  */
 #define KILL_FIRST_BIT(x) _ffb_64[(x) + 64]
 
+/**
+ * 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)
 {
 /*
@@ -131,9 +397,20 @@ Faster ( or at least cleaner ) implementation below?
 	} else {
 		return FIND_FIRST_BIT(GB(value, 0, 6));
 	}
-
 }
 
+/**
+ * Clear the first bit in an integer.
+ *
+ * This function returns a value where the first bit (from LSB)
+ * is cleared. This function checks, similar to FindFirstBit2x64,
+ * the bits at 0x3F3F.
+ *
+ * @param value The value to clear the first bit
+ * @return The new value with the first bit cleared
+ * @see KILL_FIRST_BIT
+ * @see FindFirstBit2x64
+ */
 static inline int KillFirstBit2x64(int value)
 {
 	if (GB(value, 0, 8) == 0) {
@@ -143,16 +420,77 @@ static inline int KillFirstBit2x64(int value)
 	}
 }
 
-/** returns true if value a has only one bit set to 1 */
+/**
+ * Returns true if value a has only one bit set to 1
+ *
+ * This macro returns true if only one bit is set.
+ *
+ * @param a The value to check
+ * @return True if only one bit is set, false else
+ */
 #define HAS_SINGLE_BIT(a) ( ((a) & ((a) - 1)) == 0)
 
-/* [min,max), strictly less than */
+/**
+ * Checks if a byte is in an interval.
+ *
+ * This macro returns true if a byte value is in the interval of [min, max).
+ *
+ * @param a The byte value to check
+ * @param min The minimum of the interval
+ * @param max The maximum of the interval
+ * @see IS_INSIDE_1D
+ */
 #define IS_BYTE_INSIDE(a, min, max) ((byte)((a) - (min)) < (byte)((max) - (min)))
-#define IS_INT_INSIDE(a, min, max) ((uint)((a) - (min)) < (uint)((max) - (min)))
 
+/**
+ * Checks if an int is in an interval.
+ *
+ * This macro returns true if a integer value is in the interval of [min, max).
+ *
+ * @param a The integer value to check
+ * @param min The minimum of the interval
+ * @param max The maximum of the interval
+ * @see IS_INSIDE_1D
+ */
+#define IS_INT_INSIDE(a, min, max) ((uint)((a) - (min)) < (uint)((max) - (min)))
 
+/**
+ * Flips a coin with a given probability.
+ *
+ * This macro can be used to get true or false randomized according to a
+ * given probability. The parameter a and b create a percent value with
+ * (a/b). The macro returns true in (a/b) percent.
+ *
+ * @param a The numerator of the fraction
+ * @param b The denominator of the fraction, must of course not be null
+ * @return True in (a/b) percent
+ */
 #define CHANCE16(a, b) ((uint16)Random() <= (uint16)((65536 * (a)) / (b)))
+
+/**
+ * Flips a coin with a given probability and saves the randomize-number in a variable.
+ *
+ * This macro uses the same parameters as the CHANCE16 marco. The third parameter
+ * must be a variable the randomize-number from Random() is saved in.
+ *
+ * @param a The numerator of the fraction, see CHANCE16
+ * @param b The denominator of the fraction, see CHANCE16
+ * @param r The variable to save the randomize-number from Random()
+ * @return True in (a/b) percent
+ */
 #define CHANCE16R(a, b, r) ((uint16)(r = Random()) <= (uint16)((65536 * (a)) / (b)))
+
+/**
+ * Checks if a given randomize-number is below a given probability.
+ *
+ * This macro is used to check if the given probability by the fraction of (a/b)
+ * is greater than the given randomize-number v.
+ *
+ * @param a The numerator of the fraction, see CHANCE16
+ * @param b The denominator of the fraction, see CHANCE16
+ * @param v The given randomize-number
+ * @return True if v is less or equals (a/b)
+ */
 #define CHANCE16I(a, b, v) ((uint16)(v) <= (uint16)((65536 * (a)) / (b)))