bg_lib.c

quakeIII源码这个不用我多说吧

//
//
// bg_lib,c -- standard C library replacement routines used by code
// compiled for the virtual machine

#include "q_shared.h"

/*-
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)qsort.c	8.1 (Berkeley) 6/4/93";
#endif
static const char rcsid[] =
#endif /* LIBC_SCCS and not lint */

// bk001127 - needed for DLL's
#if !defined( Q3_VM )
typedef int		 cmp_t(const void *, const void *);
#endif

static char* med3(char *, char *, char *, cmp_t *);
static void	 swapfunc(char *, char *, int, int);

#ifndef min
#define min(a, b)	(a) < (b) ? a : b
#endif

/*
 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
 */
#define swapcode(TYPE, parmi, parmj, n) { 		\
	long i = (n) / sizeof (TYPE); 			\
	register TYPE *pi = (TYPE *) (parmi); 		\
	register TYPE *pj = (TYPE *) (parmj); 		\
	do { 						\
		register TYPE	t = *pi;		\
		*pi++ = *pj;				\
		*pj++ = t;				\
        } while (--i > 0);				\
}

#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
	es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;

static void
swapfunc(a, b, n, swaptype)
	char *a, *b;
	int n, swaptype;
{
	if(swaptype <= 1)
		swapcode(long, a, b, n)
	else
		swapcode(char, a, b, n)
}

#define swap(a, b)					\
	if (swaptype == 0) {				\
		long t = *(long *)(a);			\
		*(long *)(a) = *(long *)(b);		\
		*(long *)(b) = t;			\
	} else						\
		swapfunc(a, b, es, swaptype)

#define vecswap(a, b, n) 	if ((n) > 0) swapfunc(a, b, n, swaptype)

static char *
med3(a, b, c, cmp)
	char *a, *b, *c;
	cmp_t *cmp;
{
	return cmp(a, b) < 0 ?
	       (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
              :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
}

void
qsort(a, n, es, cmp)
	void *a;
	size_t n, es;
	cmp_t *cmp;
{
	char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
	int d, r, swaptype, swap_cnt;

loop:	SWAPINIT(a, es);
	swap_cnt = 0;
	if (n < 7) {
		for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
			for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
			     pl -= es)
				swap(pl, pl - es);
		return;
	}
	pm = (char *)a + (n / 2) * es;
	if (n > 7) {
		pl = a;
		pn = (char *)a + (n - 1) * es;
		if (n > 40) {
			d = (n / 8) * es;
			pl = med3(pl, pl + d, pl + 2 * d, cmp);
			pm = med3(pm - d, pm, pm + d, cmp);
			pn = med3(pn - 2 * d, pn - d, pn, cmp);
		}
		pm = med3(pl, pm, pn, cmp);
	}
	swap(a, pm);
	pa = pb = (char *)a + es;

	pc = pd = (char *)a + (n - 1) * es;
	for (;;) {
		while (pb <= pc && (r = cmp(pb, a)) <= 0) {
			if (r == 0) {
				swap_cnt = 1;
				swap(pa, pb);
				pa += es;
			}
			pb += es;
		}
		while (pb <= pc && (r = cmp(pc, a)) >= 0) {
			if (r == 0) {
				swap_cnt = 1;
				swap(pc, pd);
				pd -= es;
			}
			pc -= es;
		}
		if (pb > pc)
			break;
		swap(pb, pc);
		swap_cnt = 1;
		pb += es;
		pc -= es;
	}
	if (swap_cnt == 0) {  /* Switch to insertion sort */
		for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
			for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
			     pl -= es)
				swap(pl, pl - es);
		return;
	}

	pn = (char *)a + n * es;
	r = min(pa - (char *)a, pb - pa);
	vecswap(a, pb - r, r);
	r = min(pd - pc, pn - pd - es);
	vecswap(pb, pn - r, r);
	if ((r = pb - pa) > es)
		qsort(a, r / es, es, cmp);
	if ((r = pd - pc) > es) {
		/* Iterate rather than recurse to save stack space */
		a = pn - r;
		n = r / es;
		goto loop;
	}
/*		qsort(pn - r, r / es, es, cmp);*/
}

//==================================================================================


// this file is excluded from release builds because of intrinsics

// bk001211 - gcc errors on compiling strcpy:  parse error before `__extension__'
#if defined ( Q3_VM )

size_t strlen( const char *string ) {
	const char	*s;

	s = string;
	while ( *s ) {
		s++;
	}
	return s - string;
}


char *strcat( char *strDestination, const char *strSource ) {
	char	*s;

	s = strDestination;
	while ( *s ) {
		s++;
	}
	while ( *strSource ) {
		*s++ = *strSource++;
	}
	*s = 0;
	return strDestination;
}

char *strcpy( char *strDestination, const char *strSource ) {
	char *s;

	s = strDestination;
	while ( *strSource ) {
		*s++ = *strSource++;
	}
	*s = 0;
	return strDestination;
}


int strcmp( const char *string1, const char *string2 ) {
	while ( *string1 == *string2 && *string1 && *string2 ) {
		string1++;
		string2++;
	}
	return *string1 - *string2;
}


char *strchr( const char *string, int c ) {
	while ( *string ) {
		if ( *string == c ) {
			return ( char * )string;
		}
		string++;
	}
	return (char *)0;
}

char *strstr( const char *string, const char *strCharSet ) {
	while ( *string ) {
		int		i;

		for ( i = 0 ; strCharSet[i] ; i++ ) {
			if ( string[i] != strCharSet[i] ) {
				break;
			}
		}
		if ( !strCharSet[i] ) {
			return (char *)string;
		}
		string++;
	}
	return (char *)0;
}
#endif // bk001211

// bk001120 - presumably needed for Mac
//#if !defined(_MSC_VER) && !defined(__linux__)
// bk001127 - undid undo
#if defined ( Q3_VM )
int tolower( int c ) {
	if ( c >= 'A' && c <= 'Z' ) {
		c += 'a' - 'A';
	}
	return c;
}


int toupper( int c ) {
	if ( c >= 'a' && c <= 'z' ) {
		c += 'A' - 'a';
	}
	return c;
}

#endif
//#ifndef _MSC_VER

void *memmove( void *dest, const void *src, size_t count ) {
	int		i;

	if ( dest > src ) {
		for ( i = count-1 ; i >= 0 ; i-- ) {
			((char *)dest)[i] = ((char *)src)[i];
		}
	} else {
		for ( i = 0 ; i < count ; i++ ) {
			((char *)dest)[i] = ((char *)src)[i];
		}
	}
	return dest;
}


#if 0

double floor( double x ) {
	return (int)(x + 0x40000000) - 0x40000000;
}

void *memset( void *dest, int c, size_t count ) {
	while ( count-- ) {
		((char *)dest)[count] = c;
	}
	return dest;
}

void *memcpy( void *dest, const void *src, size_t count ) {
	while ( count-- ) {
		((char *)dest)[count] = ((char *)src)[count];
	}
	return dest;
}

char *strncpy( char *strDest, const char *strSource, size_t count ) {
	char	*s;

	s = strDest;
	while ( *strSource && count ) {
		*s++ = *strSource++;
		count--;
	}
	while ( count-- ) {
		*s++ = 0;
	}
	return strDest;
}

double sqrt( double x ) {
	float	y;
	float	delta;
	float	maxError;

	if ( x <= 0 ) {
		return 0;
	}

	// initial guess
	y = x / 2;

	// refine
	maxError = x * 0.001;

	do {
		delta = ( y * y ) - x;
		y -= delta / ( 2 * y );
	} while ( delta > maxError || delta < -maxError );

	return y;
}


float sintable[1024] = {
0.000000,0.001534,0.003068,0.004602,0.006136,0.007670,0.009204,0.010738,
0.012272,0.013805,0.015339,0.016873,0.018407,0.019940,0.021474,0.023008,
0.024541,0.026075,0.027608,0.029142,0.030675,0.032208,0.033741,0.035274,
0.036807,0.038340,0.039873,0.041406,0.042938,0.044471,0.046003,0.047535,
0.049068,0.050600,0.052132,0.053664,0.055195,0.056727,0.058258,0.059790,
0.061321,0.062852,0.064383,0.065913,0.067444,0.068974,0.070505,0.072035,
0.073565,0.075094,0.076624,0.078153,0.079682,0.081211,0.082740,0.084269,
0.085797,0.087326,0.088854,0.090381,0.091909,0.093436,0.094963,0.096490,
0.098017,0.099544,0.101070,0.102596,0.104122,0.105647,0.107172,0.108697,
0.110222,0.111747,0.113271,0.114795,0.116319,0.117842,0.119365,0.120888,
0.122411,0.123933,0.125455,0.126977,0.128498,0.130019,0.131540,0.133061,
0.134581,0.136101,0.137620,0.139139,0.140658,0.142177,0.143695,0.145213,
0.146730,0.148248,0.149765,0.151281,0.152797,0.154313,0.155828,0.157343,
0.158858,0.160372,0.161886,0.163400,0.164913,0.166426,0.167938,0.169450,
0.170962,0.172473,0.173984,0.175494,0.177004,0.178514,0.180023,0.181532,
0.183040,0.184548,0.186055,0.187562,0.189069,0.190575,0.192080,0.193586,
0.195090,0.196595,0.198098,0.199602,0.201105,0.202607,0.204109,0.205610,
0.207111,0.208612,0.210112,0.211611,0.213110,0.214609,0.216107,0.217604,
0.219101,0.220598,0.222094,0.223589,0.225084,0.226578,0.228072,0.229565,
0.231058,0.232550,0.234042,0.235533,0.237024,0.238514,0.240003,0.241492,
0.242980,0.244468,0.245955,0.247442,0.248928,0.250413,0.251898,0.253382,
0.254866,0.256349,0.257831,0.259313,0.260794,0.262275,0.263755,0.265234,
0.266713,0.268191,0.269668,0.271145,0.272621,0.274097,0.275572,0.277046,
0.278520,0.279993,0.281465,0.282937,0.284408,0.285878,0.287347,0.288816,
0.290285,0.291752,0.293219,0.294685,0.296151,0.297616,0.299080,0.300543,
0.302006,0.303468,0.304929,0.306390,0.307850,0.309309,0.310767,0.312225,
0.313682,0.315138,0.316593,0.318048,0.319502,0.320955,0.322408,0.323859,
0.325310,0.326760,0.328210,0.329658,0.331106,0.332553,0.334000,0.335445,
0.336890,0.338334,0.339777,0.341219,0.342661,0.344101,0.345541,0.346980,
0.348419,0.349856,0.351293,0.352729,0.354164,0.355598,0.357031,0.358463,
0.359895,0.361326,0.362756,0.364185,0.365613,0.367040,0.368467,0.369892,
0.371317,0.372741,0.374164,0.375586,0.377007,0.378428,0.379847,0.381266,
0.382683,0.384100,0.385516,0.386931,0.388345,0.389758,0.391170,0.392582,
0.393992,0.395401,0.396810,0.398218,0.399624,0.401030,0.402435,0.403838,
0.405241,0.406643,0.408044,0.409444,0.410843,0.412241,0.413638,0.415034,
0.416430,0.417824,0.419217,0.420609,0.422000,0.423390,0.424780,0.426168,
0.427555,0.428941,0.430326,0.431711,0.433094,0.434476,0.435857,0.437237,
0.438616,0.439994,0.441371,0.442747,0.444122,0.445496,0.446869,0.448241,
0.449611,0.450981,0.452350,0.453717,0.455084,0.456449,0.457813,0.459177,
0.460539,0.461900,0.463260,0.464619,0.465976,0.467333,0.468689,0.470043,
0.471397,0.472749,0.474100,0.475450,0.476799,0.478147,0.479494,0.480839,
0.482184,0.483527,0.484869,0.486210,0.487550,0.488889,0.490226,0.491563,
0.492898,0.494232,0.495565,0.496897,0.498228,0.499557,0.500885,0.502212,
0.503538,0.504863,0.506187,0.507509,0.508830,0.510150,0.511469,0.512786,
0.514103,0.515418,0.516732,0.518045,0.519356,0.520666,0.521975,0.523283,
0.524590,0.525895,0.527199,0.528502,0.529804,0.531104,0.532403,0.533701,
0.534998,0.536293,0.537587,0.538880,0.540171,0.541462,0.542751,0.544039,
0.545325,0.546610,0.547894,0.549177,0.550458,0.551738,0.553017,0.554294,
0.555570,0.556845,0.558119,0.559391,0.560662,0.561931,0.563199,0.564466,
0.565732,0.566996,0.568259,0.569521,0.570781,0.572040,0.573297,0.574553,
0.575808,0.577062,0.578314,0.579565,0.580814,0.582062,0.583309,0.584554,
0.585798,0.587040,0.588282,0.589521,0.590760,0.591997,0.593232,0.594466,
0.595699,0.596931,0.598161,0.599389,0.600616,0.601842,0.603067,0.604290,
0.605511,0.606731,0.607950,0.609167,0.610383,0.611597,0.612810,0.614022,
0.615232,0.616440,0.617647,0.618853,0.620057,0.621260,0.622461,0.623661,
0.624859,0.626056,0.627252,0.628446,0.629638,0.630829,0.632019,0.633207,
0.634393,0.635578,0.636762,0.637944,0.639124,0.640303,0.641481,0.642657,
0.643832,0.645005,0.646176,0.647346,0.648514,0.649681,0.650847,0.652011,
0.653173,0.654334,0.655493,0.656651,0.657807,0.658961,0.660114,0.661266,
0.662416,0.663564,0.664711,0.665856,0.667000,0.668142,0.669283,0.670422,
0.671559,0.672695,0.673829,0.674962,0.676093,0.677222,0.678350,0.679476,
0.680601,0.681724,0.682846,0.683965,0.685084,0.686200,0.687315,0.688429,
0.689541,0.690651,0.691759,0.692866,0.693971,0.695075,0.696177,0.697278,
0.698376,0.699473,0.700569,0.701663,0.702755,0.703845,0.704934,0.706021,
0.707107,0.708191,0.709273,0.710353,0.711432,0.712509,0.713585,0.714659,
0.715731,0.716801,0.717870,0.718937,0.720003,0.721066,0.722128,0.723188,
0.724247,0.725304,0.726359,0.727413,0.728464,0.729514,0.730563,0.731609,
0.732654,0.733697,0.734739,0.735779,0.736817,0.737853,0.738887,0.739920,
0.740951,0.741980,0.743008,0.744034,0.745058,0.746080,0.747101,0.748119,
0.749136,0.750152,0.751165,0.752177,0.753187,0.754195,0.755201,0.756206,
0.757209,0.758210,0.759209,0.760207,0.761202,0.762196,0.763188,0.764179,
0.765167,0.766154,0.767139,0.768122,0.769103,0.770083,0.771061,0.772036,
0.773010,0.773983,0.774953,0.775922,0.776888,0.777853,0.778817,0.779778,
0.780737,0.781695,0.782651,0.783605,0.784557,0.785507,0.786455,0.787402,