Re: [cc65-devel] c64 - getting seemingly random chars on screen

[<sje...@sh...>]

You could also write your own, it's all part of the fun. 😉

I wrote this years ago using conio functions (and I see some things I'd fix now...)

/* text_input
 *
 * Get some text input from the user.  Pass in the max number of characters
 * to be accepted, and a pointer to a string that is at least as big plus one
 * for the null terminator to hold the string.
 *
 * Rudimentary editing is supported (backspace, ctrl-arrows) when a non-empty
 * string is passed in.
 *
 * Returns the number of characters entered if everything went ok
 * and the user pressed return, 0 if the user pressed Escape.
 */
unsigned char __fastcall__ text_input(unsigned char x, unsigned char y, char *text, unsigned char max)
{
  register char c;
  register unsigned char i;


  //--- Initialize ---//
  i = 0;
  cursor(1);
  cputsxy(x, y, text);                  // show text
  gotoxy(x, y); 

  while (1) {
    c = cgetc();

    switch(c) {
      case 27:                          // user pressed escape
	text[0] = 27;                   // flag that user pressed escape 
	cursor(0);                      // since a blank string and escape 
	return(0);                      // both have a return value of zero
	break;

      case 155:                         // user pressed return
	text[strlen(text)] = '\0';
	cursor(0);
	return(strlen(text));
	break;

      case 126:                         // user pressed backspace 
	if (i != 0) {
	  --i;
	  if (i == (strlen(text)-1))
	    text[i] = '\0';
	  else
	    text[i] = ' ';
	  cputcxy(x+i, y, ' ');
	  gotoxy(x+i, y);
	}
	break;

      case 30:                          // user pressed left arrow
	if (i != 0) {
	  --i;
	  gotoxy(x+i, y);
	}
	break;

      case 31:                          // user pressed right arrow
	if (i < strlen(text)) {
	  ++i;
	  gotoxy(x+i, y); 
	}

      default:
	if (i == max) continue;                     // maxed out

	if (isprint(c)) {                           // is a printable char
	  text[i] = c;
	  cputc(c);
	  ++i;
	}
	break;
    }
  }
  // end of function
}

-----Original Message-----
From: Dirk Jagdmann <do...@cu...> 
Sent: March 3, 2021 4:24 PM
To: cc6...@li...
Subject: Re: [cc65-devel] c64 - getting seemingly random chars on screen


> (the highscore was getting saved in a few places it didn't need to), I 
> guess I'll look into better ways of reading keyboard input.  I have a 
> vague memory of being told/reading/somehow learning, that scanf() 
> wasn't considered 'safe' anyways.
>
you can start with the textInput() function in

https://github.com/doj/dracopy/blob/master/src/ops.c


-- 
---> Dirk Jagdmann
----> http://cubic.org/~doj
-----> http://llg.cubic.org



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