Port of the http://prophessor.16mb.com/autopaint.html

autopaint.c

/**
 * autopaint.c
 * Copyright (c) PROPHESSOR 05.08.2018
 * $ sudo apt install libncurses-dev
 * $ gcc -g autopaint.c -o autopaint -lncurses && ./autopaint
 */

#include <ncurses.h>
#include <stdlib.h>
#include <time.h>

#define SYMBOL '#'

void usleep(int);
short rnd(short min, short max) { return rand() % max + min; }

int main() {
    srand(time(NULL));

    short SCW;
    short SCH;

    initscr();
    getmaxyx(stdscr, SCH, SCW);
    keypad(stdscr, true);
    nodelay(stdscr, true);
    noecho();
    curs_set(0);

    bool isColorful = has_colors();
    if(isColorful) {
        if(start_color() == OK) {
            init_pair(1, COLOR_RED,     COLOR_BLACK);
            init_pair(2, COLOR_YELLOW,  COLOR_BLACK);
            init_pair(3, COLOR_GREEN,   COLOR_BLACK);
            init_pair(4, COLOR_CYAN,    COLOR_BLACK);
            init_pair(5, COLOR_BLUE,    COLOR_BLACK);
            init_pair(6, COLOR_MAGENTA, COLOR_BLACK);
        } else {
            printw("Can't initialize color mode!\n");
            isColorful = false;
        }
    } else printw("Your terminal seems doesn't support colors!\n");

    printw("Hello world! Press BACKSPACE key to exit.\n");

    short x = SCW / 2;
    short y = SCH / 2;
    move(y, x);

    while(1) {
        if(getch() == KEY_BACKSPACE)        break;

        usleep(10 * 1000);

        short move = rnd(0, 4);
        switch(move) {
            case 0: if(y > 0)       y--;    break;
            case 1: if(x > SCW / 2) x--;    break;
            case 2: if(y < SCH - 1) y++;    break;
            case 3: if(x < SCW - 1) x++;    break;
        }

        if(isColorful) attrset(COLOR_PAIR(rnd(1, 7)));

        move(y, x);
        addch(SYMBOL);
        move(y, SCW - x);
        addch(SYMBOL);

        refresh();
    }

    endwin();
    return 0;
}