void tty_putc(int wno, char c) /* print one character on the screen */
{
int t;
switch(c)
{
case '\r': /* -> carriage return */
window_info[wno].xpos = 0;
break;
case '\n': /* -> newline (with implicit cr) */
window_info[wno].xpos = 0;
window_info[wno].ypos++;
break;
case 8: /* -> backspace */
t = window_info[wno].xpos + window_info[wno].ypos * window_info[wno].width; /* get linear address */
if(t > 0) t--;
/* if not in home position, step back */
if(window_info[wno].xpos > 0)
{
window_info[wno].xpos--;
}
else if(window_info[wno].ypos > 0)
{
window_info[wno].ypos--;
window_info[wno].xpos = window_info[wno].width - 1;
}
*(window_info[wno].buf + ((t / window_info[wno].width) * scrwidth) + ((t % window_info[wno].width))) = ' ' | (window_info[wno].colour << 8); /* put space under the cursor */
break;
default: /* -> all other characters */
if(c < ' ') break; /* ignore non printable ascii chars */
t = window_info[wno].xpos + window_info[wno].ypos * window_info[wno].width;
*(window_info[wno].buf + ((t / window_info[wno].width) * scrwidth) + ((t % window_info[wno].width))) = c | (window_info[wno].colour << 8);
window_info[wno].xpos++; /* step cursor one character */
if(window_info[wno].xpos == window_info[wno].width) /* to next line if required */
{
window_info[wno].xpos = 0;
window_info[wno].ypos++;
}
break;
}
if(window_info[wno].ypos == window_info[wno].height) /* the cursor moved off of the screen? */
{
tty_scrollup(wno); /* scroll the screen up */
window_info[wno].ypos--; /* and move the cursor back */
}
/* and finally, set the cursor */
if (window_info[wno].movcursor == TRUE)
{
tty_setcursor(wno, window_info[wno].xpos, window_info[wno].ypos);
}
}
void cls(int wno) /* clear the screen by filling it with spaces */
{
int t;
for(t = 0; t < window_info[wno].width * window_info[wno].height; t++) /* clear the screen */
{
*(window_info[wno].buf + ((t / window_info[wno].width) * scrwidth) + ((t % window_info[wno].width))) = ' ' | (window_info[wno].colour << 8);
}
window_info[wno].xpos = 0;
window_info[wno].ypos = 0; /* set cursor to home location */
if (window_info[wno].movcursor == TRUE)
{
tty_setcursor(wno, 0, 0); /* call the hw. cursor setup */
}
}
void tty_updatecursor() {
tty_setcursor(tty_x, tty_y);
}
void gotoxy(int wno, unsigned x, unsigned y)
{
window_info[wno].xpos = x;
window_info[wno].ypos = y; /* set cursor to home location */
tty_setcursor(wno, x, y); /* call the hw. cursor setup */
}
