scanf function

scanf function

sebastien nicaisse

Member #2,252

April 2002

Hello,

I'm new members and I discoved the allegro library. But, i have a little probleme. I want write a editable text.
I use the scanf function but it doesn't function.

Exist a function in allegro library which looks like to a scanf function ?

I thank to answer my question.

SEB

Thomas Harte

Member #33

April 2000

No, Allegro has no equivalent of scanf, you must write your own! But what you can do is write a function to accept a string as input, then leave the parsing of contents of that string to sscanf. E.g.

1#include <stdarg.h>
2 
3int textscanf(BITMAP *bmp, const FONT *f, int x, int y, int colour, const char *format, ...)
4{
 char buffer[512];
 int bufptr, quit;
 va_list ap;
 int key, bcol;
9 
 /* set text in use to the empty string */
 sprintf(buffer, "");
 bufptr = quit = 0;
13 
 /* find out what colour the background is */
 bcol = getpixel(x, y);
16 
 /* take characters into buffer */
 clear_keybuf();
 while(!quit)
 {
    key = readkey();
22 
    switch(key >> 8)
    {
       case KEY_ENTER : quit = 1; break;
       case KEY_BACKSPACE : if(bufptr) bufptr--; break;
       default : if(bufptr < 511) {buffer[bufptr] = key&0xff; bufptr++; buffer[bufptr] = '\0';} break;
    }
29 
    textout(bmp, font, buffer, x, y, colour);
    rectfill(bmp, x+text_length(font, buffer), y, bmp->w, y+text_height(font), bcol);
 }
33 
 /* pass on to vscanf */
 va_start(ap, format);
 vscanf(format, ap);
 va_end(ap);
38}

Which isn't code useful for everyone because of the assumptions made about the background (i.e. that it is a single colour) and the fact that you can't do anything else at the same time, so its really only useful on the screen bitmap, but I think it gets the point across?

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