uparse.c

利用VC++和OpenGVS结合编的一个关于火车运行的三维模拟程序。是OpenGVS三维初学者的应该参考的好范例。

/***************************************************************************
*
*  uparse.c --
*
*	Sample command line parser for Train demo
*
****************************************************************************/
#include <g_sys.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <g_consts.h>
#include <g_file.h>
#include <gv_env.h>
#include <gv_types.h>
#include <gv_user.h>
#include <gv_cmd.h>
#include <gv_imp.h>
#include <g_msg.h>
#include <tgifts.h>

#include "train.h"
#include "hostdata.h"

/* Globals */
G_Name pcf_train_file = "";		/* If specified, becomes our train   */
G_Boolean pcf_detail_texture = G_TRUE;	/* G_TRUE to allow detail texture     */
G_Boolean pcf_gfx = G_TRUE;		/* Graphics are on by default         */
G_Boolean pcf_pause = G_FALSE;		/* If G_TRUE, runtime will pause      */
G_Boolean pcf_realtime = G_TRUE;	/* G_FALSE to run wo/real-time rates  */
G_Boolean pcf_record = G_FALSE;		/* G_TRUE to record ownship object    */

#if G_SYS_SGL
G_Boolean pcf_cursor = G_TRUE;	/* G_TRUE to draw our own mouse cursor  */
#else
G_Boolean pcf_cursor = G_FALSE;	/* System presumably draws its own cursor */
#endif

/***************************************************************************
*
*  print_usage --
*
*	Local function to print out intended startup options (usage)
*
****************************************************************************/
static void print_usage( char * program )
{
    static char str2[] = 
"----------------- Application specific -------------------------\n"
"    -h       display this information (startup help)\n"
#if G_SYS_SGL
" -nocursor   startup without a software cursor\n"
#endif
"\n"
" -nographics run application without graphics\n"
" -nodetail   disallow detail (micro) texture\n";

    char str1[256];
    char * strt;
    int nchrs;

    sprintf( str1,
        "Usage: %s [options] [train_filename]\n\n"
        "where optional [train_filename] is a database to fly through\n"
        "and command line options include:\n\n", program );

    nchrs = tparse_display_usage( &strt );
    if( nchrs > 0 )
    {
        tgprintf( stdout, "%s%s%s", str1, strt, str2 );
	G_free( strt );
    }
    else
        tgprintf( stdout, "%s%s", str1, str2 );
}


/***************************************************************************
*
*  GV_user_parse_cmd --
*
*	Parse the Unix command line and perform project specific actions
*
****************************************************************************/
int GV_user_parse_cmd( int argc, char *argv[] )
{
    int cmds_used ;
    int argix ;

    /* Default for this program unless changed with startup option */
    G_msg_set_severity_verbosity( G_MSG_SEV_INFO_BRIEF );

    cmds_used = 0;
    for( argix=1; argix<argc; argix++ )
    {   
	/*  while arguments remain to be processed */
	cmds_used++;

	if (argv[argix][0] == '-')
	{   
	    /* Argument starts with "-" */
	    char *token;

	    for (token = argv[argix] + 1 ; *token ; token++)
	    {
		/* See if it is a common token */
		int tsts;
		int nchrs;
		nchrs = strlen(token);

		tsts = tparse_cmd( token );
		if( tsts )
		    break;	/* Known common token... taken care of... */

		if (token[1])
		{
		    if (strcmp( token, "nodetail") == 0)
			pcf_detail_texture = G_FALSE;

		    else if (strcmp( token, "nocursor") == 0)
			pcf_cursor = G_FALSE;

		    else if (strcmp( token, "nographics") == 0)
			pcf_gfx = G_FALSE;

		    else
			fprintf(stderr, "GV_user_parse_cmd: "
			    "Illegal option \"-%s\"\n", token);

		    break ;
		}
		else if( nchrs == 1 )
		{
		    /* Now check for valid single character tokens (e.g., -a) */
		    switch (*token)
		    {
		    case 'h':
			print_usage( argv[0] );
			exit( EXIT_SUCCESS );
			break;

		    default:
			fprintf(stderr, "GV_user_parse_cmd: "
			    "Illegal flag \"-%c\"\n", *token);
			break;
		    }
		}
	    }
	}   /*  argument starts with "-" */

	else
	{   
	    /* Argument does not start with "-", so check for
	        valid keywords */
	    char * pkwd ;
	    char * pscan ;
	    char parent_dir[256];
	    char device[3] = "";
	    int nchrs;
	    const char * etrans;

	    /*  treat argument as keyword or perhaps keyword=value */
	    pkwd = argv[argix] ;
	    pscan = pkwd ;

	    while (*pscan && !isspace(*pscan) && (*pscan != '='))
		pscan++ ;		/*  skip past keyword */

	    while (isspace(*pscan))
		pscan++ ;		/*  skip past blanks */
	    if (*pscan == '=')
	    {
		pscan++ ;
		while (isspace(*pscan))
		    pscan++ ;		/*  skip past blanks again */
	    }

	    /* Assume this is a train database filename */
	    strcpy( pcf_train_file, argv[argix] );

	    G_file_head( pcf_train_file, sizeof(parent_dir),
		     parent_dir, &nchrs );

	    if( nchrs > 1 )
	    {
		tenv_txtpath_init( parent_dir, device );
		tenv_path_models_init( parent_dir );
	    }
	    etrans = G_sys_getenv( "G_ROOT" );
	    if( !etrans )
	    {
		/* No translation for G_ROOT; guess where it might be 
		    so we can find the license key (if any) plus
		    GV_ROOT for textures, etc. */
		tenv_groot_init( device );
	    }
	}   /*  argument does not start with "-" */
    }   /*  while arguments remain to be processed */

    /* Now act upon the command line (at least the "common" ones)
	now that we're done parsing options */
    tparse_preinit();

    fflush(stdout);
    fflush(stderr);

    return cmds_used;
}