Enter charaters/numbers from Keypad

Kokxxx12

Hi, I create kind od board game in Allegro and I want input numbers and dispplay these numbers on the screen. I try using sscanf and sprintf but still numbers dont display on the screen.

int width = 0;
int length = 40;
char buff[256];
char buff1[256];
char a;

if(key[KEY_RIGHT])
{
if(width<=340)
{
clear_to_color(buffer,makecol(255,255,0));
width+=40;
blit(pole1,buffer,0,0,width,length,40,40);
clear_to_color(pole1,makecol(128,0,0));
sscanf(buff,"%d",&a);

textout_ex(buffer,font,buff,width+20,length+20, makecol(255, 0, 128),-1);

rest(100);

MikiZX

Personally I do not see how you enter the numbers in the 'buff'.

Possibly 'fgets' or 'getline' are missing in your source code.

If I was programming this without the standard C functions I would do it like this:

#SelectExpand
  1// initialization
  2// initialization
  3// initialization
  4
  5   ALLEGRO_KEYBOARD_STATE kbdstate;
  6   char buff[256];
  7   int buff_pos;
  8   int a;        // better use INT though CHAR might work as well - i am not sure
  9
 10   if (!al_install_keyboard()) 
 11      {
 12      abort_example("Error installing keyboard.\n");
 13      return 1;
 14      }
 15   buff_pos=0;
 16
 17
 18
 19// in your program's main loop 
 20// (this would execute many times to receive multiple numbers)
 21// in your program's main loop
 22// in your program's main loop
 23
 24       al_get_keyboard_state(&kbdstate);
 25
 26       if (al_key_down(&kbdstate, ALLEGRO_KEY_PAD_0)) 
 27       {
 28    buff[buff_pos]=0;
 29          buff_pos++;   
 30       }
 31
 32       if (al_key_down(&kbdstate, ALLEGRO_KEY_PAD_1)) 
 33       {
 34    buff[buff_pos]=1;
 35          buff_pos++;   
 36       }
 37
 38       if (al_key_down(&kbdstate, ALLEGRO_KEY_PAD_2)) 
 39       {
 40    buff[buff_pos]=2;
 41          buff_pos++;   
 42       }
 43
 44  ....
 45
 46       if (al_key_down(&kbdstate, ALLEGRO_KEY_PAD_9)) 
 47       {
 48    buff[buff_pos]=9;
 49          buff_pos++;   
 50       }
 51
 52  if (buff_pos>255) buff_pos=0;
 53
 54  printf("%s \n", buff);    // print on screen
 55
 56  sscanf(buff,"%d",&a);    // convert text buffer to integer 'a'

Kokxxx12

I don't understand this code at all. Can you describe please what are you doing in this code?

DuncanShine

I just avoided all the buffer stuff and converted to const char* using .c_str() then outputted that using al_draw_text.

Kokxxx12

What doing this program? I creating sudoku game and I want to input numbers into the grid from keypad

Edgar Reynaldo

Turn Numlock on and monitor ALLEGRO_EVENT_KEY_CHAR events.

MikiZX

Yeah, possibly your num pad lock is off.

if you wish a complete example program this should help (once you run this program you should see two windows - one with text showing the key you pressed and one with graphics that shows different color depending on the key pressed):

#SelectExpand
   1#include <stdio.h>
   2#include <allegro5/allegro.h>
   3
   4const float FPS = 60;
   5
   6ALLEGRO_DISPLAY *display = NULL;
   7ALLEGRO_EVENT_QUEUE *event_queue = NULL;
   8ALLEGRO_TIMER *timer1 = NULL;
   9
  10bool redraw = true;
  11int input_number = 0;
  12
  13// isolating cleanup code in a single function because we use this code many times
  14// doing this will keep the rest of the source code easier to read
  15void close_and_exit()
  16{
  17   if (timer1) al_destroy_timer(timer1);
  18   if (display) al_destroy_display(display);
  19   if (event_queue) al_destroy_event_queue(event_queue);
  20   al_uninstall_system();
  21}
  22
  23// the program execution starts here with 'main' function
  24int main(int argc, char **argv){
  25
  26   // here we initialize different parts of Allegro
  27   if(!al_init()) {
  28      fprintf(stderr, "failed to initialize allegro!\n");
  29      return -1;
  30   }
  31
  32   display = al_create_display(640, 480);
  33   if(!display) {
  34      fprintf(stderr, "failed to create display!\n");
  35      close_and_exit();
  36   }
  37
  38   if (!al_install_keyboard())
  39       {
  40       fprintf(stderr, "Error installing keyboard.\n");
  41       close_and_exit();
  42       }
  43
  44   event_queue = al_create_event_queue();
  45   if(!event_queue) {
  46      fprintf(stderr, "failed to create event_queue!\n");
  47      close_and_exit();
  48   }
  49
  50   timer1 = al_create_timer(1.0 / FPS);
  51   if(!timer1) {
  52      fprintf(stderr, "failed to create timer!\n");
  53      close_and_exit();
  54   }
  55
  56   al_register_event_source(event_queue, al_get_keyboard_event_source());
  57
  58   al_register_event_source(event_queue, al_get_display_event_source(display));
  59
  60   al_register_event_source(event_queue, al_get_timer_event_source(timer1));
  61
  62   al_start_timer(timer1);
  63
  64
  65   // this is the main loop that will receive keypresses, do game logic processing and draw our game on the screen
  66   while(1)
  67   {
  68      ALLEGRO_EVENT ev;
  69      al_wait_for_event(event_queue, &ev);
  70
  71      if(ev.type == ALLEGRO_EVENT_TIMER) {
  72         redraw = true;
  73      }
  74
  75      if(ev.type == ALLEGRO_EVENT_KEY_DOWN) {
  76         if (ev.keyboard.keycode>=ALLEGRO_KEY_PAD_1 && ev.keyboard.keycode<=ALLEGRO_KEY_PAD_9)
  77         // calculate input number from input keycode
  78         // since the ALLEGRO keycodes for numeric pad are sequential
  79         // (i.e. ALLEGRO_KEY_PAD_0 is value of 36, ALLEGRO_KEY_PAD_1 is value of 37,
  80         //  ALLEGRO_KEY_PAD_2 is value of 38, ... until ALLEGRO_KEY_PAD_9
  81         // we can take the input keycode and subtract value of ALLEGRO_KEY_PAD_0 to get the
  82         // inputed number ... i.e. ALLEGRO_KEY_PAD_1-ALLEGRO_KEY_PAD_0=1 because 37-26=1
  83            input_number=ev.keyboard.keycode-ALLEGRO_KEY_PAD_0;
  84            else
  85            input_number=0;
  86
  87         if (ev.keyboard.keycode==ALLEGRO_KEY_ESCAPE)
  88            close_and_exit();
  89      }
  90
  91      if(ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE) {
  92         break;
  93      }
  94
  95      if(redraw && al_is_event_queue_empty(event_queue))
  96        {
  97         redraw = false;
  98         // convert inputed number to colors (0=black, 1=blue, 2=red, ...)
  99         int r,g,b;
 100         r=((input_number&2)/2) * 127;
 101         g=((input_number&4)/4) * 127;
 102         b=(input_number&1) * 127;
 103         al_clear_to_color(al_map_rgb(r,g,b));  // clear graphics screen
 104
 105         system("@cls||clear");     // clear the text console window
 106         printf("%d\n",input_number);   // print out the number entered
 107
 108         al_flip_display();
 109      }
 110   }
 111    close_and_exit();
 112}

Edgar Reynaldo

MikiZX, note - you have a void function returning 0. I assume you meant to call the function and then return 0.

MikiZX

Thanks Edgar, fixed now.

@Kokxxx12, I hope this can help in some way - if you still have difficulties understanding how it works then please let us know which part you do understand and we will explain the rest.

LennyLen

It might be time to point out that the OP is using A4, not A5.

Edgar Reynaldo

I need fucking glasses.

Kokxxx12, with Allegro 4 you can use readkey and shift the value 8 bits to get the keycode, then convert it to a number or digit.

MikiZX

oops.. glasses for me too then. Sorry Kokxxx12, now I understand why the code was not understandable.
I don't think I will be able to help with A4 though.
@LennyLen, thank you for pointing this out.

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