game.c

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

int kbhit() {
    struct termios oldt, newt;
    int ch;
    int oldf;
    tcgetattr(STDIN_FILENO, &oldt);
    newt = oldt;
    newt.c_lflag &= ~(ICANON | ECHO);
    tcsetattr(STDIN_FILENO, TCSANOW, &newt);
    oldf = fcntl(STDIN_FILENO, F_GETFL, 0);
    fcntl(STDIN_FILENO, F_SETFL, oldf | O_NONBLOCK);
    ch = getchar();
    tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
    fcntl(STDIN_FILENO, F_SETFL, oldf);
    if(ch != EOF) {
        ungetc(ch, stdin);
        return 1;
    }
    return 0;
}

#define FRAME_CLOCK ((double)CLOCKS_PER_SEC / (double)60)

int main(void) {
    clock_t next_refresh = 0;
    static char frames[2][255][255];
    double cnt = 0;
    int height = 24;
    int width = 80;

    int current_frame_id = 0;

    printf("\e[H\e[2J");

    for (;;) {
        int i, j;

        next_refresh += FRAME_CLOCK;

        if (kbhit() && getchar() == '\n') {
            cnt += 5;
            if (cnt > height)
                cnt = height;
        } else {
            cnt -= 0.3;
            if (cnt < 0.000001)
                cnt = 0.000001;
        }

#define f(x) (-((x) * (x) / (width * width / cnt)) + cnt)

        for (i = 0; i < height; ++i)
            for (j = 0; j < width; ++j)
                frames[current_frame_id][i][j] = ((height - i) <= f(j)) ?
                    '#' : ' ';

        while (clock() < next_refresh)
            ;

        for (i = 0; i < height; ++i)
            for (j = 0; j < width; ++j)
                if (frames[current_frame_id][i][j] != frames[current_frame_id ^ 1][i][j])
                    printf("\e[%d;%dH%c", i + 1, j + 1, frames[current_frame_id][i][j]);
        printf("\e[%d;%dH", height, width);

        current_frame_id ^= 1;

        fflush(stdout);
    }
    return 0;
}