q_shared.c

Quake 2 Source code for students by Theerthan You can also download from idsoftwares.com

		out[1] = v[1]*ilength;
		out[2] = v[2]*ilength;
	}
		
	return length;

}

void VectorMA (vec3_t veca, float scale, vec3_t vecb, vec3_t vecc)
{
	vecc[0] = veca[0] + scale*vecb[0];
	vecc[1] = veca[1] + scale*vecb[1];
	vecc[2] = veca[2] + scale*vecb[2];
}


vec_t _DotProduct (vec3_t v1, vec3_t v2)
{
	return v1[0]*v2[0] + v1[1]*v2[1] + v1[2]*v2[2];
}

void _VectorSubtract (vec3_t veca, vec3_t vecb, vec3_t out)
{
	out[0] = veca[0]-vecb[0];
	out[1] = veca[1]-vecb[1];
	out[2] = veca[2]-vecb[2];
}

void _VectorAdd (vec3_t veca, vec3_t vecb, vec3_t out)
{
	out[0] = veca[0]+vecb[0];
	out[1] = veca[1]+vecb[1];
	out[2] = veca[2]+vecb[2];
}

void _VectorCopy (vec3_t in, vec3_t out)
{
	out[0] = in[0];
	out[1] = in[1];
	out[2] = in[2];
}

void CrossProduct (vec3_t v1, vec3_t v2, vec3_t cross)
{
	cross[0] = v1[1]*v2[2] - v1[2]*v2[1];
	cross[1] = v1[2]*v2[0] - v1[0]*v2[2];
	cross[2] = v1[0]*v2[1] - v1[1]*v2[0];
}

double sqrt(double x);

vec_t VectorLength(vec3_t v)
{
	int		i;
	float	length;
	
	length = 0;
	for (i=0 ; i< 3 ; i++)
		length += v[i]*v[i];
	length = sqrt (length);		// FIXME

	return length;
}

void VectorInverse (vec3_t v)
{
	v[0] = -v[0];
	v[1] = -v[1];
	v[2] = -v[2];
}

void VectorScale (vec3_t in, vec_t scale, vec3_t out)
{
	out[0] = in[0]*scale;
	out[1] = in[1]*scale;
	out[2] = in[2]*scale;
}


int Q_log2(int val)
{
	int answer=0;
	while (val>>=1)
		answer++;
	return answer;
}



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

/*
============
COM_SkipPath
============
*/
char *COM_SkipPath (char *pathname)
{
	char	*last;
	
	last = pathname;
	while (*pathname)
	{
		if (*pathname=='/')
			last = pathname+1;
		pathname++;
	}
	return last;
}

/*
============
COM_StripExtension
============
*/
void COM_StripExtension (char *in, char *out)
{
	while (*in && *in != '.')
		*out++ = *in++;
	*out = 0;
}

/*
============
COM_FileExtension
============
*/
char *COM_FileExtension (char *in)
{
	static char exten[8];
	int		i;

	while (*in && *in != '.')
		in++;
	if (!*in)
		return "";
	in++;
	for (i=0 ; i<7 && *in ; i++,in++)
		exten[i] = *in;
	exten[i] = 0;
	return exten;
}

/*
============
COM_FileBase
============
*/
void COM_FileBase (char *in, char *out)
{
	char *s, *s2;
	
	s = in + strlen(in) - 1;
	
	while (s != in && *s != '.')
		s--;
	
	for (s2 = s ; s2 != in && *s2 != '/' ; s2--)
	;
	
	if (s-s2 < 2)
		out[0] = 0;
	else
	{
		s--;
		strncpy (out,s2+1, s-s2);
		out[s-s2] = 0;
	}
}

/*
============
COM_FilePath

Returns the path up to, but not including the last /
============
*/
void COM_FilePath (char *in, char *out)
{
	char *s;
	
	s = in + strlen(in) - 1;
	
	while (s != in && *s != '/')
		s--;

	strncpy (out,in, s-in);
	out[s-in] = 0;
}


/*
==================
COM_DefaultExtension
==================
*/
void COM_DefaultExtension (char *path, char *extension)
{
	char    *src;
//
// if path doesn't have a .EXT, append extension
// (extension should include the .)
//
	src = path + strlen(path) - 1;

	while (*src != '/' && src != path)
	{
		if (*src == '.')
			return;                 // it has an extension
		src--;
	}

	strcat (path, extension);
}

/*
============================================================================

					BYTE ORDER FUNCTIONS

============================================================================
*/

qboolean	bigendien;

// can't just use function pointers, or dll linkage can
// mess up when qcommon is included in multiple places
short	(*_BigShort) (short l);
short	(*_LittleShort) (short l);
int		(*_BigLong) (int l);
int		(*_LittleLong) (int l);
float	(*_BigFloat) (float l);
float	(*_LittleFloat) (float l);

short	BigShort(short l){return _BigShort(l);}
short	LittleShort(short l) {return _LittleShort(l);}
int		BigLong (int l) {return _BigLong(l);}
int		LittleLong (int l) {return _LittleLong(l);}
float	BigFloat (float l) {return _BigFloat(l);}
float	LittleFloat (float l) {return _LittleFloat(l);}

short   ShortSwap (short l)
{
	byte    b1,b2;

	b1 = l&255;
	b2 = (l>>8)&255;

	return (b1<<8) + b2;
}

short	ShortNoSwap (short l)
{
	return l;
}

int    LongSwap (int l)
{
	byte    b1,b2,b3,b4;

	b1 = l&255;
	b2 = (l>>8)&255;
	b3 = (l>>16)&255;
	b4 = (l>>24)&255;

	return ((int)b1<<24) + ((int)b2<<16) + ((int)b3<<8) + b4;
}

int	LongNoSwap (int l)
{
	return l;
}

float FloatSwap (float f)
{
	union
	{
		float	f;
		byte	b[4];
	} dat1, dat2;
	
	
	dat1.f = f;
	dat2.b[0] = dat1.b[3];
	dat2.b[1] = dat1.b[2];
	dat2.b[2] = dat1.b[1];
	dat2.b[3] = dat1.b[0];
	return dat2.f;
}

float FloatNoSwap (float f)
{
	return f;
}

/*
================
Swap_Init
================
*/
void Swap_Init (void)
{
	byte	swaptest[2] = {1,0};

// set the byte swapping variables in a portable manner	
	if ( *(short *)swaptest == 1)
	{
		bigendien = false;
		_BigShort = ShortSwap;
		_LittleShort = ShortNoSwap;
		_BigLong = LongSwap;
		_LittleLong = LongNoSwap;
		_BigFloat = FloatSwap;
		_LittleFloat = FloatNoSwap;
	}
	else
	{
		bigendien = true;
		_BigShort = ShortNoSwap;
		_LittleShort = ShortSwap;
		_BigLong = LongNoSwap;
		_LittleLong = LongSwap;
		_BigFloat = FloatNoSwap;
		_LittleFloat = FloatSwap;
	}

}



/*
============
va

does a varargs printf into a temp buffer, so I don't need to have
varargs versions of all text functions.
FIXME: make this buffer size safe someday
============
*/
char	*va(char *format, ...)
{
	va_list		argptr;
	static char		string[1024];
	
	va_start (argptr, format);
	vsprintf (string, format,argptr);
	va_end (argptr);

	return string;	
}


char	com_token[MAX_TOKEN_CHARS];

/*
==============
COM_Parse

Parse a token out of a string
==============
*/
char *COM_Parse (char **data_p)
{
	int		c;
	int		len;
	char	*data;

	data = *data_p;
	len = 0;
	com_token[0] = 0;
	
	if (!data)
	{
		*data_p = NULL;
		return "";
	}
		
// skip whitespace
skipwhite:
	while ( (c = *data) <= ' ')
	{
		if (c == 0)
		{
			*data_p = NULL;
			return "";
		}
		data++;
	}
	
// skip // comments
	if (c=='/' && data[1] == '/')
	{
		while (*data && *data != '\n')
			data++;
		goto skipwhite;
	}

// handle quoted strings specially
	if (c == '\"')
	{
		data++;
		while (1)
		{
			c = *data++;
			if (c=='\"' || !c)
			{
				com_token[len] = 0;
				*data_p = data;
				return com_token;
			}
			if (len < MAX_TOKEN_CHARS)
			{
				com_token[len] = c;
				len++;
			}
		}
	}

// parse a regular word
	do
	{
		if (len < MAX_TOKEN_CHARS)
		{
			com_token[len] = c;
			len++;
		}
		data++;
		c = *data;
	} while (c>32);

	if (len == MAX_TOKEN_CHARS)
	{
//		Com_Printf ("Token exceeded %i chars, discarded.\n", MAX_TOKEN_CHARS);
		len = 0;
	}
	com_token[len] = 0;

	*data_p = data;
	return com_token;
}


/*
===============
Com_PageInMemory

===============
*/
int	paged_total;

void Com_PageInMemory (byte *buffer, int size)
{
	int		i;

	for (i=size-1 ; i>0 ; i-=4096)
		paged_total += buffer[i];
}



/*
============================================================================

					LIBRARY REPLACEMENT FUNCTIONS

============================================================================
*/

// FIXME: replace all Q_stricmp with Q_strcasecmp
int Q_stricmp (char *s1, char *s2)
{
#if defined(WIN32)
	return _stricmp (s1, s2);
#else
	return strcasecmp (s1, s2);
#endif
}


int Q_strncasecmp (char *s1, char *s2, int n)
{
	int		c1, c2;
	
	do
	{
		c1 = *s1++;
		c2 = *s2++;

		if (!n--)
			return 0;		// strings are equal until end point
		
		if (c1 != c2)
		{
			if (c1 >= 'a' && c1 <= 'z')
				c1 -= ('a' - 'A');
			if (c2 >= 'a' && c2 <= 'z')
				c2 -= ('a' - 'A');
			if (c1 != c2)
				return -1;		// strings not equal
		}
	} while (c1);
	
	return 0;		// strings are equal
}

int Q_strcasecmp (char *s1, char *s2)
{
	return Q_strncasecmp (s1, s2, 99999);
}



void Com_sprintf (char *dest, int size, char *fmt, ...)
{
	int		len;
	va_list		argptr;
	char	bigbuffer[0x10000];

	va_start (argptr,fmt);
	len = vsprintf (bigbuffer,fmt,argptr);
	va_end (argptr);
	if (len >= size)
		Com_Printf ("Com_sprintf: overflow of %i in %i\n", len, size);
	strncpy (dest, bigbuffer, size-1);
}

/*
=====================================================================

  INFO STRINGS

=====================================================================
*/

/*
===============
Info_ValueForKey

Searches the string for the given
key and returns the associated value, or an empty string.
===============
*/
char *Info_ValueForKey (char *s, char *key)
{
	char	pkey[512];
	static	char value[2][512];	// use two buffers so compares
								// work without stomping on each other
	static	int	valueindex;
	char	*o;
	
	valueindex ^= 1;
	if (*s == '\\')
		s++;
	while (1)
	{
		o = pkey;
		while (*s != '\\')
		{
			if (!*s)
				return "";
			*o++ = *s++;
		}
		*o = 0;
		s++;

		o = value[valueindex];

		while (*s != '\\' && *s)
		{
			if (!*s)
				return "";
			*o++ = *s++;
		}
		*o = 0;

		if (!strcmp (key, pkey) )
			return value[valueindex];

		if (!*s)
			return "";
		s++;
	}
}

void Info_RemoveKey (char *s, char *key)
{
	char	*start;
	char	pkey[512];
	char	value[512];
	char	*o;

	if (strstr (key, "\\"))
	{
//		Com_Printf ("Can't use a key with a \\\n");
		return;
	}

	while (1)
	{
		start = s;
		if (*s == '\\')
			s++;
		o = pkey;
		while (*s != '\\')
		{
			if (!*s)
				return;
			*o++ = *s++;
		}
		*o = 0;
		s++;

		o = value;
		while (*s != '\\' && *s)
		{
			if (!*s)
				return;
			*o++ = *s++;
		}
		*o = 0;

		if (!strcmp (key, pkey) )
		{
			strcpy (start, s);	// remove this part
			return;
		}

		if (!*s)
			return;
	}

}


/*
==================
Info_Validate

Some characters are illegal in info strings because they
can mess up the server's parsing
==================
*/
qboolean Info_Validate (char *s)
{
	if (strstr (s, "\""))
		return false;
	if (strstr (s, ";"))
		return false;
	return true;
}

void Info_SetValueForKey (char *s, char *key, char *value)
{
	char	newi[MAX_INFO_STRING], *v;
	int		c;
	int		maxsize = MAX_INFO_STRING;

	if (strstr (key, "\\") || strstr (value, "\\") )
	{
		Com_Printf ("Can't use keys or values with a \\\n");
		return;
	}

	if (strstr (key, ";") )
	{
		Com_Printf ("Can't use keys or values with a semicolon\n");
		return;
	}

	if (strstr (key, "\"") || strstr (value, "\"") )
	{
		Com_Printf ("Can't use keys or values with a \"\n");
		return;
	}

	if (strlen(key) > MAX_INFO_KEY-1 || strlen(value) > MAX_INFO_KEY-1)
	{
		Com_Printf ("Keys and values must be < 64 characters.\n");
		return;
	}
	Info_RemoveKey (s, key);
	if (!value || !strlen(value))
		return;

	Com_sprintf (newi, sizeof(newi), "\\%s\\%s", key, value);

	if (strlen(newi) + strlen(s) > maxsize)
	{
		Com_Printf ("Info string length exceeded\n");
		return;
	}

	// only copy ascii values
	s += strlen(s);
	v = newi;
	while (*v)
	{
		c = *v++;
		c &= 127;		// strip high bits
		if (c >= 32 && c < 127)
			*s++ = c;
	}
	*s = 0;
}

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