//------------------------------------------------------------|
//  This example tries to show the use of pthreadss,          |
//  it only runs on Linux, because of the pthread.h           |
//  header file.                                              |
//                                                            |
//  It has many bugs, you can only run it in a terminal       |
//  started in a X-session, otherwise it will crash, the main |
//  problem is that i commented the pthread_join line, and    |
//  i made that because that line waitss for the thread to    |
//  end, and in this example it wouldn't work, i'm almost     |
//  sure that changing the attr attributes can make this      |
//  run better, any way, i didn't find the solution, another  |
//  problem is that the thread runs too fast, so it's         |
//  difficult to apreciate well the moves of the character.   |
//  So, if you think you can resolve those problems, please   |
//  send me a mail, or just modify the code, but please, let  |
//  know, 'cause i really want to learn the solution.         |
//                                                            |
//  Author: Juan Francisco Benavides Nanni.                   |
//  mail: elnanni@gmail.com                                   |
//  URL: http://mmabj.tk                                      |
//  date: 29/12/2005                                          |
//------------------------------------------------------------|

#include <stdio.h>
#include <pthread.h>
#include <termios.h>
#include <unistd.h>

#define MAXWIDX 78
#define MAXWIDY 19
#define MIN 0
#define CENTER 10

#define gotoxy(x,y) printf("\x1B[%i;%iH",(y),(x))
#define clrscr() printf("\x1B[2J")

#define UP 115
#define DOWN 120
#define LEFT 122
#define RIG 99
#define SALE 27

void mover(int *opc);
int mygetch();

int main(){
    pthread_t thread_ID;
    pthread_attr_t attr;
    int opc, last, x, y;
    pthread_attr_init(&attr);
    pthread_attr_setscope(&attr, PTHREAD_SCOPE_PROCESS);
    pthread_setconcurrency(2);
    char car = '^';
    opc = UP;
    y = CENTER;
    x = y * 4;
    while(1){
        if(opc == SALE) break;
        clrscr();
        switch(opc){
            case UP:
                if(y > MIN) y -= 1;
                else y = MAXWIDY;
                car = '^';
                break;
            case DOWN:
                if(y < MAXWIDY) y += 1;
                else y = MIN;
                car = 'v';
                break;
            case LEFT:
                if(x > MIN) x -= 1;
                else x = MAXWIDX;
                car = '<';
                break;
            case RIG:
                if(x < MAXWIDX) x += 1;
                else x = MIN;
                car = '>';
                break;
            case SALE:
                break;
            default:
                opc = last;
        }
        gotoxy(x, y);
        printf("%c", car);
        last = opc;
        pthread_create(&thread_ID, &attr, (void *) mover, &opc);
        //pthread_join(thread_ID, NULL);
    }
}

void mover(int *opc){
    *opc = mygetch();
}

int mygetch(){
    struct termios oldt, newt;
    int ch;
    tcgetattr( STDIN_FILENO, &oldt );
    newt = oldt;
    newt.c_lflag &= ~( ICANON | ECHO );
    tcsetattr( STDIN_FILENO, TCSANOW, &newt );
    ch = getchar();
    tcsetattr( STDIN_FILENO, TCSANOW, &oldt );
    return ch;
}