257 lines
11 KiB
C++
257 lines
11 KiB
C++
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
/**
|
|
* Contains misc. useful macros & defines.
|
|
* \file IceUtils.h
|
|
* \author Pierre Terdiman (collected from various sources)
|
|
* \date April, 4, 2000
|
|
*/
|
|
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
|
|
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// Include Guard
|
|
#ifndef __ICEUTILS_H__
|
|
#define __ICEUTILS_H__
|
|
|
|
#define START_RUNONCE { static bool __RunOnce__ = false; if(!__RunOnce__){
|
|
#define END_RUNONCE __RunOnce__ = true;}}
|
|
|
|
//! Reverse all the bits in a 32 bit word (from Steve Baker's Cute Code Collection)
|
|
//! (each line can be done in any order.
|
|
inline_ void ReverseBits(udword& n)
|
|
{
|
|
n = ((n >> 1) & 0x55555555) | ((n << 1) & 0xaaaaaaaa);
|
|
n = ((n >> 2) & 0x33333333) | ((n << 2) & 0xcccccccc);
|
|
n = ((n >> 4) & 0x0f0f0f0f) | ((n << 4) & 0xf0f0f0f0);
|
|
n = ((n >> 8) & 0x00ff00ff) | ((n << 8) & 0xff00ff00);
|
|
n = ((n >> 16) & 0x0000ffff) | ((n << 16) & 0xffff0000);
|
|
// Etc for larger intergers (64 bits in Java)
|
|
// NOTE: the >> operation must be unsigned! (>>> in java)
|
|
}
|
|
|
|
//! Count the number of '1' bits in a 32 bit word (from Steve Baker's Cute Code Collection)
|
|
inline_ udword CountBits(udword n)
|
|
{
|
|
// This relies of the fact that the count of n bits can NOT overflow
|
|
// an n bit interger. EG: 1 bit count takes a 1 bit interger, 2 bit counts
|
|
// 2 bit interger, 3 bit count requires only a 2 bit interger.
|
|
// So we add all bit pairs, then each nible, then each byte etc...
|
|
n = (n & 0x55555555) + ((n & 0xaaaaaaaa) >> 1);
|
|
n = (n & 0x33333333) + ((n & 0xcccccccc) >> 2);
|
|
n = (n & 0x0f0f0f0f) + ((n & 0xf0f0f0f0) >> 4);
|
|
n = (n & 0x00ff00ff) + ((n & 0xff00ff00) >> 8);
|
|
n = (n & 0x0000ffff) + ((n & 0xffff0000) >> 16);
|
|
// Etc for larger intergers (64 bits in Java)
|
|
// NOTE: the >> operation must be unsigned! (>>> in java)
|
|
return n;
|
|
}
|
|
|
|
//! Even faster?
|
|
inline_ udword CountBits2(udword bits)
|
|
{
|
|
bits = bits - ((bits >> 1) & 0x55555555);
|
|
bits = ((bits >> 2) & 0x33333333) + (bits & 0x33333333);
|
|
bits = ((bits >> 4) + bits) & 0x0F0F0F0F;
|
|
return (bits * 0x01010101) >> 24;
|
|
}
|
|
|
|
//! Spread out bits. EG 00001111 -> 0101010101
|
|
//! 00001010 -> 0100010000
|
|
//! This is used to interleve to intergers to produce a `Morten Key'
|
|
//! used in Space Filling Curves (See DrDobbs Journal, July 1999)
|
|
//! Order is important.
|
|
inline_ void SpreadBits(udword& n)
|
|
{
|
|
n = ( n & 0x0000ffff) | (( n & 0xffff0000) << 16);
|
|
n = ( n & 0x000000ff) | (( n & 0x0000ff00) << 8);
|
|
n = ( n & 0x000f000f) | (( n & 0x00f000f0) << 4);
|
|
n = ( n & 0x03030303) | (( n & 0x0c0c0c0c) << 2);
|
|
n = ( n & 0x11111111) | (( n & 0x22222222) << 1);
|
|
}
|
|
|
|
// Next Largest Power of 2
|
|
// Given a binary integer value x, the next largest power of 2 can be computed by a SWAR algorithm
|
|
// that recursively "folds" the upper bits into the lower bits. This process yields a bit vector with
|
|
// the same most significant 1 as x, but all 1's below it. Adding 1 to that value yields the next
|
|
// largest power of 2. For a 32-bit value:
|
|
inline_ udword nlpo2(udword x)
|
|
{
|
|
x |= (x >> 1);
|
|
x |= (x >> 2);
|
|
x |= (x >> 4);
|
|
x |= (x >> 8);
|
|
x |= (x >> 16);
|
|
return x+1;
|
|
}
|
|
|
|
//! Test to see if a number is an exact power of two (from Steve Baker's Cute Code Collection)
|
|
inline_ bool IsPowerOfTwo(udword n) { return ((n&(n-1))==0); }
|
|
|
|
//! Zero the least significant '1' bit in a word. (from Steve Baker's Cute Code Collection)
|
|
inline_ void ZeroLeastSetBit(udword& n) { n&=(n-1); }
|
|
|
|
//! Set the least significant N bits in a word. (from Steve Baker's Cute Code Collection)
|
|
inline_ void SetLeastNBits(udword& x, udword n) { x|=~(~0<<n); }
|
|
|
|
//! Classic XOR swap (from Steve Baker's Cute Code Collection)
|
|
//! x ^= y; /* x' = (x^y) */
|
|
//! y ^= x; /* y' = (y^(x^y)) = x */
|
|
//! x ^= y; /* x' = (x^y)^x = y */
|
|
inline_ void Swap(udword& x, udword& y) { x ^= y; y ^= x; x ^= y; }
|
|
|
|
//! Little/Big endian (from Steve Baker's Cute Code Collection)
|
|
//!
|
|
//! Extra comments by Kenny Hoff:
|
|
//! Determines the byte-ordering of the current machine (little or big endian)
|
|
//! by setting an integer value to 1 (so least significant bit is now 1); take
|
|
//! the address of the int and cast to a byte pointer (treat integer as an
|
|
//! array of four bytes); check the value of the first byte (must be 0 or 1).
|
|
//! If the value is 1, then the first byte least significant byte and this
|
|
//! implies LITTLE endian. If the value is 0, the first byte is the most
|
|
//! significant byte, BIG endian. Examples:
|
|
//! integer 1 on BIG endian: 00000000 00000000 00000000 00000001
|
|
//! integer 1 on LITTLE endian: 00000001 00000000 00000000 00000000
|
|
//!---------------------------------------------------------------------------
|
|
//! int IsLittleEndian() { int x=1; return ( ((char*)(&x))[0] ); }
|
|
inline_ char LittleEndian() { int i = 1; return *((char*)&i); }
|
|
|
|
//!< Alternative abs function
|
|
inline_ udword abs_(sdword x) { sdword y= x >> 31; return (x^y)-y; }
|
|
|
|
//!< Alternative min function
|
|
inline_ sdword min_(sdword a, sdword b) { sdword delta = b-a; return a + (delta&(delta>>31)); }
|
|
|
|
// Determine if one of the bytes in a 4 byte word is zero
|
|
inline_ BOOL HasNullByte(udword x) { return ((x + 0xfefefeff) & (~x) & 0x80808080); }
|
|
|
|
// To find the smallest 1 bit in a word EG: ~~~~~~10---0 => 0----010---0
|
|
inline_ udword LowestOneBit(udword w) { return ((w) & (~(w)+1)); }
|
|
// inline_ udword LowestOneBit_(udword w) { return ((w) & (-(w))); }
|
|
|
|
// Most Significant 1 Bit
|
|
// Given a binary integer value x, the most significant 1 bit (highest numbered element of a bit set)
|
|
// can be computed using a SWAR algorithm that recursively "folds" the upper bits into the lower bits.
|
|
// This process yields a bit vector with the same most significant 1 as x, but all 1's below it.
|
|
// Bitwise AND of the original value with the complement of the "folded" value shifted down by one
|
|
// yields the most significant bit. For a 32-bit value:
|
|
inline_ udword msb32(udword x)
|
|
{
|
|
x |= (x >> 1);
|
|
x |= (x >> 2);
|
|
x |= (x >> 4);
|
|
x |= (x >> 8);
|
|
x |= (x >> 16);
|
|
return (x & ~(x >> 1));
|
|
}
|
|
|
|
/*
|
|
"Just call it repeatedly with various input values and always with the same variable as "memory".
|
|
The sharpness determines the degree of filtering, where 0 completely filters out the input, and 1
|
|
does no filtering at all.
|
|
|
|
I seem to recall from college that this is called an IIR (Infinite Impulse Response) filter. As opposed
|
|
to the more typical FIR (Finite Impulse Response).
|
|
|
|
Also, I'd say that you can make more intelligent and interesting filters than this, for example filters
|
|
that remove wrong responses from the mouse because it's being moved too fast. You'd want such a filter
|
|
to be applied before this one, of course."
|
|
|
|
(JCAB on Flipcode)
|
|
*/
|
|
inline_ float FeedbackFilter(float val, float& memory, float sharpness)
|
|
{
|
|
ASSERT(sharpness>=0.0f && sharpness<=1.0f && "Invalid sharpness value in feedback filter");
|
|
if(sharpness<0.0f) sharpness = 0.0f;
|
|
else if(sharpness>1.0f) sharpness = 1.0f;
|
|
return memory = val * sharpness + memory * (1.0f - sharpness);
|
|
}
|
|
|
|
//! If you can guarantee that your input domain (i.e. value of x) is slightly
|
|
//! limited (abs(x) must be < ((1<<31u)-32767)), then you can use the
|
|
//! following code to clamp the resulting value into [-32768,+32767] range:
|
|
inline_ int ClampToInt16(int x)
|
|
{
|
|
// ASSERT(abs(x) < (int)((1<<31u)-32767));
|
|
|
|
int delta = 32767 - x;
|
|
x += (delta>>31) & delta;
|
|
delta = x + 32768;
|
|
x -= (delta>>31) & delta;
|
|
return x;
|
|
}
|
|
|
|
// Generic functions
|
|
template<class Type> inline_ void TSwap(Type& a, Type& b) { const Type c = a; a = b; b = c; }
|
|
template<class Type> inline_ Type TClamp(const Type& x, const Type& lo, const Type& hi) { return ((x<lo) ? lo : (x>hi) ? hi : x); }
|
|
|
|
template<class Type> inline_ void TSort(Type& a, Type& b)
|
|
{
|
|
if(a>b) TSwap(a, b);
|
|
}
|
|
|
|
template<class Type> inline_ void TSort(Type& a, Type& b, Type& c)
|
|
{
|
|
if(a>b) TSwap(a, b);
|
|
if(b>c) TSwap(b, c);
|
|
if(a>b) TSwap(a, b);
|
|
if(b>c) TSwap(b, c);
|
|
}
|
|
|
|
// Prevent nasty user-manipulations (strategy borrowed from Charles Bloom)
|
|
// #define PREVENT_COPY(curclass) void operator = (const curclass& object) { ASSERT(!"Bad use of operator ="); }
|
|
// ... actually this is better !
|
|
#define PREVENT_COPY(cur_class) private: cur_class(const cur_class& object); cur_class& operator=(const cur_class& object);
|
|
|
|
//! TO BE DOCUMENTED
|
|
#define OFFSET_OF(Class, Member) (size_t)&(((Class*)0)->Member)
|
|
//! TO BE DOCUMENTED
|
|
#define ARRAYSIZE(p) (sizeof(p)/sizeof(p[0]))
|
|
|
|
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
/**
|
|
* Returns the alignment of the input address.
|
|
* \fn Alignment()
|
|
* \param address [in] address to check
|
|
* \return the best alignment (e.g. 1 for odd addresses, etc)
|
|
*/
|
|
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
FUNCTION ICECORE_API udword Alignment(udword address);
|
|
|
|
#define IS_ALIGNED_2(x) ((x&1)==0)
|
|
#define IS_ALIGNED_4(x) ((x&3)==0)
|
|
#define IS_ALIGNED_8(x) ((x&7)==0)
|
|
|
|
inline_ void _prefetch(void const* ptr) { (void)*(char const volatile *)ptr; }
|
|
|
|
// Compute implicit coords from an index:
|
|
// The idea is to get back 2D coords from a 1D index.
|
|
// For example:
|
|
//
|
|
// 0 1 2 ... nbu-1
|
|
// nbu nbu+1 i ...
|
|
//
|
|
// We have i, we're looking for the equivalent (u=2, v=1) location.
|
|
// i = u + v*nbu
|
|
// <=> i/nbu = u/nbu + v
|
|
// Since 0 <= u < nbu, u/nbu = 0 (integer)
|
|
// Hence: v = i/nbu
|
|
// Then we simply put it back in the original equation to compute u = i - v*nbu
|
|
inline_ void Compute2DCoords(udword& u, udword& v, udword i, udword nbu)
|
|
{
|
|
v = i / nbu;
|
|
u = i - (v * nbu);
|
|
}
|
|
|
|
// In 3D: i = u + v*nbu + w*nbu*nbv
|
|
// <=> i/(nbu*nbv) = u/(nbu*nbv) + v/nbv + w
|
|
// u/(nbu*nbv) is null since u/nbu was null already.
|
|
// v/nbv is null as well for the same reason.
|
|
// Hence w = i/(nbu*nbv)
|
|
// Then we're left with a 2D problem: i' = i - w*nbu*nbv = u + v*nbu
|
|
inline_ void Compute3DCoords(udword& u, udword& v, udword& w, udword i, udword nbu, udword nbu_nbv)
|
|
{
|
|
w = i / (nbu_nbv);
|
|
Compute2DCoords(u, v, i - (w * nbu_nbv), nbu);
|
|
}
|
|
|
|
#endif // __ICEUTILS_H__
|