q_shared.c

quakeIII源码这个不用我多说吧

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
//
// q_shared.c -- stateless support routines that are included in each code dll
#include "q_shared.h"

float Com_Clamp( float min, float max, float value ) {
	if ( value < min ) {
		return min;
	}
	if ( value > max ) {
		return max;
	}
	return value;
}


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


/*
==================
COM_DefaultExtension
==================
*/
void COM_DefaultExtension (char *path, int maxSize, const char *extension ) {
	char	oldPath[MAX_QPATH];
	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--;
	}

	Q_strncpyz( oldPath, path, sizeof( oldPath ) );
	Com_sprintf( path, maxSize, "%s%s", oldPath, extension );
}

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

					BYTE ORDER FUNCTIONS

============================================================================
*/
/*
// can't just use function pointers, or dll linkage can
// mess up when qcommon is included in multiple places
static short	(*_BigShort) (short l);
static short	(*_LittleShort) (short l);
static int		(*_BigLong) (int l);
static int		(*_LittleLong) (int l);
static qint64	(*_BigLong64) (qint64 l);
static qint64	(*_LittleLong64) (qint64 l);
static float	(*_BigFloat) (const float *l);
static float	(*_LittleFloat) (const 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);}
qint64 	BigLong64 (qint64 l) {return _BigLong64(l);}
qint64 	LittleLong64 (qint64 l) {return _LittleLong64(l);}
float	BigFloat (const float *l) {return _BigFloat(l);}
float	LittleFloat (const 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;
}

qint64 Long64Swap (qint64 ll)
{
	qint64	result;

	result.b0 = ll.b7;
	result.b1 = ll.b6;
	result.b2 = ll.b5;
	result.b3 = ll.b4;
	result.b4 = ll.b3;
	result.b5 = ll.b2;
	result.b6 = ll.b1;
	result.b7 = ll.b0;

	return result;
}

qint64 Long64NoSwap (qint64 ll)
{
	return ll;
}

typedef union {
    float	f;
    unsigned int i;
} _FloatByteUnion;

float FloatSwap (const float *f) {
	const _FloatByteUnion *in;
	_FloatByteUnion out;

	in = (_FloatByteUnion *)f;
	out.i = LongSwap(in->i);

	return out.f;
}

float FloatNoSwap (const 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)
	{
		_BigShort = ShortSwap;
		_LittleShort = ShortNoSwap;
		_BigLong = LongSwap;
		_LittleLong = LongNoSwap;
		_BigLong64 = Long64Swap;
		_LittleLong64 = Long64NoSwap;
		_BigFloat = FloatSwap;
		_LittleFloat = FloatNoSwap;
	}
	else
	{
		_BigShort = ShortNoSwap;
		_LittleShort = ShortSwap;
		_BigLong = LongNoSwap;
		_LittleLong = LongSwap;
		_BigLong64 = Long64NoSwap;
		_LittleLong64 = Long64Swap;
		_BigFloat = FloatNoSwap;
		_LittleFloat = FloatSwap;
	}

}
*/

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

PARSING

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

static	char	com_token[MAX_TOKEN_CHARS];
static	char	com_parsename[MAX_TOKEN_CHARS];
static	int		com_lines;

void COM_BeginParseSession( const char *name )
{
	com_lines = 0;
	Com_sprintf(com_parsename, sizeof(com_parsename), "%s", name);
}

int COM_GetCurrentParseLine( void )
{
	return com_lines;
}

char *COM_Parse( char **data_p )
{
	return COM_ParseExt( data_p, qtrue );
}

void COM_ParseError( char *format, ... )
{
	va_list argptr;
	static char string[4096];

	va_start (argptr, format);
	vsprintf (string, format, argptr);
	va_end (argptr);

	Com_Printf("ERROR: %s, line %d: %s\n", com_parsename, com_lines, string);
}

void COM_ParseWarning( char *format, ... )
{
	va_list argptr;
	static char string[4096];

	va_start (argptr, format);
	vsprintf (string, format, argptr);
	va_end (argptr);

	Com_Printf("WARNING: %s, line %d: %s\n", com_parsename, com_lines, string);
}

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

Parse a token out of a string
Will never return NULL, just empty strings

If "allowLineBreaks" is qtrue then an empty
string will be returned if the next token is
a newline.
==============
*/
static char *SkipWhitespace( char *data, qboolean *hasNewLines ) {
	int c;

	while( (c = *data) <= ' ') {
		if( !c ) {
			return NULL;
		}
		if( c == '\n' ) {
			com_lines++;
			*hasNewLines = qtrue;
		}
		data++;
	}

	return data;
}

int COM_Compress( char *data_p ) {
	char *in, *out;
	int c;
	qboolean newline = qfalse, whitespace = qfalse;

	in = out = data_p;
	if (in) {
		while ((c = *in) != 0) {
			// skip double slash comments
			if ( c == '/' && in[1] == '/' ) {
				while (*in && *in != '\n') {
					in++;
				}
			// skip /* */ comments
			} else if ( c == '/' && in[1] == '*' ) {
				while ( *in && ( *in != '*' || in[1] != '/' ) ) 
					in++;
				if ( *in ) 
					in += 2;
                        // record when we hit a newline
                        } else if ( c == '\n' || c == '\r' ) {
                            newline = qtrue;
                            in++;
                        // record when we hit whitespace
                        } else if ( c == ' ' || c == '\t') {
                            whitespace = qtrue;
                            in++;
                        // an actual token
			} else {
                            // if we have a pending newline, emit it (and it counts as whitespace)
                            if (newline) {
                                *out++ = '\n';
                                newline = qfalse;
                                whitespace = qfalse;
                            } if (whitespace) {
                                *out++ = ' ';
                                whitespace = qfalse;
                            }
                            
                            // copy quoted strings unmolested
                            if (c == '"') {
                                    *out++ = c;
                                    in++;
                                    while (1) {
                                        c = *in;
                                        if (c && c != '"') {
                                            *out++ = c;
                                            in++;
                                        } else {
                                            break;
                                        }
                                    }
                                    if (c == '"') {
                                        *out++ = c;
                                        in++;
                                    }
                            } else {
                                *out = c;
                                out++;
                                in++;
                            }
			}
		}
	}
	*out = 0;
	return out - data_p;
}

char *COM_ParseExt( char **data_p, qboolean allowLineBreaks )
{
	int c = 0, len;
	qboolean hasNewLines = qfalse;
	char *data;

	data = *data_p;
	len = 0;
	com_token[0] = 0;

	// make sure incoming data is valid
	if ( !data )
	{
		*data_p = NULL;
		return com_token;
	}

	while ( 1 )
	{
		// skip whitespace
		data = SkipWhitespace( data, &hasNewLines );
		if ( !data )
		{
			*data_p = NULL;
			return com_token;
		}
		if ( hasNewLines && !allowLineBreaks )
		{
			*data_p = data;
			return com_token;
		}

		c = *data;

		// skip double slash comments
		if ( c == '/' && data[1] == '/' )
		{
			data += 2;
			while (*data && *data != '\n') {
				data++;
			}
		}
		// skip /* */ comments
		else if ( c=='/' && data[1] == '*' ) 
		{
			data += 2;
			while ( *data && ( *data != '*' || data[1] != '/' ) ) 
			{
				data++;
			}
			if ( *data ) 
			{
				data += 2;
			}
		}
		else
		{
			break;
		}
	}

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


#if 0
// no longer used
/*
===============
COM_ParseInfos
===============
*/
int COM_ParseInfos( char *buf, int max, char infos[][MAX_INFO_STRING] ) {
	char	*token;
	int		count;
	char	key[MAX_TOKEN_CHARS];

	count = 0;

	while ( 1 ) {
		token = COM_Parse( &buf );
		if ( !token[0] ) {
			break;
		}
		if ( strcmp( token, "{" ) ) {
			Com_Printf( "Missing { in info file\n" );
			break;
		}

		if ( count == max ) {
			Com_Printf( "Max infos exceeded\n" );
			break;
		}

		infos[count][0] = 0;
		while ( 1 ) {
			token = COM_ParseExt( &buf, qtrue );
			if ( !token[0] ) {
				Com_Printf( "Unexpected end of info file\n" );
				break;
			}
			if ( !strcmp( token, "}" ) ) {
				break;
			}
			Q_strncpyz( key, token, sizeof( key ) );

			token = COM_ParseExt( &buf, qfalse );
			if ( !token[0] ) {
				strcpy( token, "<NULL>" );
			}
			Info_SetValueForKey( infos[count], key, token );
		}
		count++;
	}

	return count;
}
#endif


/*
==================
COM_MatchToken
==================
*/
void COM_MatchToken( char **buf_p, char *match ) {
	char	*token;

	token = COM_Parse( buf_p );
	if ( strcmp( token, match ) ) {
		Com_Error( ERR_DROP, "MatchToken: %s != %s", token, match );
	}
}


/*
=================
SkipBracedSection

The next token should be an open brace.
Skips until a matching close brace is found.
Internal brace depths are properly skipped.
=================
*/
void SkipBracedSection (char **program) {
	char			*token;
	int				depth;

	depth = 0;
	do {
		token = COM_ParseExt( program, qtrue );
		if( token[1] == 0 ) {
			if( token[0] == '{' ) {
				depth++;
			}
			else if( token[0] == '}' ) {
				depth--;
			}
		}
	} while( depth && *program );
}

/*
=================
SkipRestOfLine
=================
*/
void SkipRestOfLine ( char **data ) {
	char	*p;
	int		c;

	p = *data;
	while ( (c = *p++) != 0 ) {
		if ( c == '\n' ) {
			com_lines++;
			break;
		}
	}

	*data = p;
}


void Parse1DMatrix (char **buf_p, int x, float *m) {
	char	*token;
	int		i;

	COM_MatchToken( buf_p, "(" );

	for (i = 0 ; i < x ; i++) {
		token = COM_Parse(buf_p);
		m[i] = atof(token);
	}

	COM_MatchToken( buf_p, ")" );
}

void Parse2DMatrix (char **buf_p, int y, int x, float *m) {
	int		i;

	COM_MatchToken( buf_p, "(" );

	for (i = 0 ; i < y ; i++) {
		Parse1DMatrix (buf_p, x, m + i * x);
	}