/* terminal.h -- */
#ifndef __TERMINAL_H__
#define __TERMINAL_H__

#include "defines.h"    /* COLOR, SCROLLCODE */
#include "retcode.h"
#include "utf8.h"

/* The editor communicates with the display using a high level interface.
   A "TERM" structure holds useful variables, and indirect pointers to
   routines that do useful operations.  The low level get and put routines
   are here too.  This lets a terminal, in addition to having non standard
   commands, have funny get and put character code too.  The calls might
   get changed to "termp->t_field" style in the future, to make it possible
   to run more than one terminal type.
 */
typedef struct {
    const short t_maxrow ;          /* max number of rows allowable */
    const short t_maxcol ;          /* max number of columns allowable */
    short t_mrow ;                  /* max number of rows displayable */
    short t_nrow ;                  /* current number of rows displayed */
    short t_mcol ;                  /* max number of rows displayable */
    short t_ncol ;                  /* current number of columns displayed */
    short t_margin ;                /* min margin for extended lines */
    short t_scrsiz ;                /* size of scroll region */
    int t_pause ;                   /* # times thru update to pause */
    void (*t_open)( void) ;         /* Open terminal at the start */
    void (*t_close)( void) ;        /* Close terminal at end. */
    void (*t_kopen)( void) ;        /* Open keyboard */
    void (*t_kclose)( void) ;       /* close keyboard */
    int (*t_getchar)( void) ;       /* Get character from keyboard */
    int (*t_putchar)( unicode_t) ;  /* Put character to display */
    void (*t_flush) (void) ;        /* Flush output buffers */
    void (*t_move)( int, int) ;     /* Move the cursor, origin 0 */
    void (*t_eeol)( void) ;         /* Erase to end of line */
    void (*t_eeop)( void) ;         /* Erase to end of page */
    void (*t_beep)( void) ;         /* Beep */
    void (*t_rev)( int) ;           /* set reverse video state */
    int (*t_rez)( char *) ;         /* change screen resolution */
#if COLOR
    int (*t_setfor)() ;             /* set forground color */
    int (*t_setback)() ;            /* set background color */
#endif
#if SCROLLCODE
    void (*t_scroll)( int, int,int) ; /* scroll a region of the screen */
#endif
} terminal_t ;

/* TEMPORARY macros for terminal I/O (to be placed in a machine dependant
   place later)
 */

#define TTopen      (*term.t_open)
#define TTclose     (*term.t_close)
#define TTkopen     (*term.t_kopen)
#define TTkclose    (*term.t_kclose)
#define TTgetc      (*term.t_getchar)
#define TTputc      (*term.t_putchar)
#define TTflush     (*term.t_flush)
#define TTmove      (*term.t_move)
#define TTeeol      (*term.t_eeol)
#define TTeeop      (*term.t_eeop)
#define TTbeep      (*term.t_beep)
#define TTrev       (*term.t_rev)
#define TTrez       (*term.t_rez)
#if COLOR
#define TTforg      (*term.t_setfor)
#define TTbacg      (*term.t_setback)
#endif

/* Terminal table defined only in tcap.c */
extern terminal_t term ;

extern boolean eolexist ;   /* does clear to EOL exist?     */
extern boolean revexist ;   /* does reverse video exist?    */
extern boolean sgarbf ;     /* State of screen unknown      */

extern char sres[] ;        /* Current screen resolution.   */
                            /* NORMAL, CGA, EGA, VGA    */

#endif
/* end of terminal.h */