C-Kurs/Pong/Musterlösung

Musterlösung

#include <stdlib.h>
#include <curses.h>

/* dimensions of the field */
#define WIDTH 40
#define HEIGHT 15
#define PADDLE_HEIGHT 3

/* positions of play things */
int pos_p1_y;
int pos_p2_y;
int pos_ball_x;
int pos_ball_y;
int dir_ball_x;
int dir_ball_y;

/* scores */
int score_p1 = 0;
int score_p2 = 0;

void init() {
	initscr(); /* init for curses */
	noecho();  /* don't display typed chars */
	cbreak();  /* don't buffer terminal lines */
	keypad(stdscr, TRUE);  /* for special keys (e.g. arrow keys) */
	nodelay(stdscr, TRUE); /* don't block in getch() */ 
}

void place_paddles() {
	pos_p1_y = HEIGHT / 2 - PADDLE_HEIGHT / 2;
	pos_p2_y = HEIGHT / 2 - PADDLE_HEIGHT / 2;
}

void place_ball(int dir_x) {
	pos_ball_x = WIDTH / 2;
	pos_ball_y = HEIGHT / 2;
	dir_ball_x = dir_x;
	dir_ball_y = 1;
}

void print_field() {
	clear();
	int x,y;
	
	/* print score */
	printw("         %i                     %i\n", score_p1, score_p2);

	/* print upper frame */
	printw("+");
	for(x=0; x<WIDTH; x++) {
		printw("-");
	}
	printw("+\n");

	for (y=0; y<HEIGHT; y++) {
		/* first column (x==0) is for player1's paddle */
		if (y >= pos_p1_y && y < pos_p1_y+PADDLE_HEIGHT) {
			printw("|#");
		} else if (pos_ball_x == 0 && pos_ball_y == y) {
			printw("|*");
		} else {
			printw("| ");
		}

		/* middle columns (0 < x < WIDTH-1) anywhere the ball can be */
		for (x=1; x<WIDTH-1; x++) {
			if (y == pos_ball_y && x == pos_ball_x) {
				printw("*");
			} else {
				printw(" ");
			}
		}

		/* last column (x==WIDTH-1) is for player2's paddle */
		if (y >= pos_p2_y && y < pos_p2_y+PADDLE_HEIGHT) {
			printw("#|\n");
		} else if (pos_ball_x == WIDTH-1 && pos_ball_y == y) {
			printw("*|\n");
		} else {
			printw(" |\n");
		}
	}

	/* print lower frame */
	printw("+");
	for(x=0; x<WIDTH; x++) {
		printw("-");
	}
	printw("+\n");

	refresh();
}

void key_processing() {
	int ch = getch();
	if (ch == KEY_UP) {
		if (pos_p1_y > 0) {
			pos_p1_y--;
		}
	} else if (ch == KEY_DOWN) {
		if (pos_p1_y < HEIGHT-PADDLE_HEIGHT) {
			pos_p1_y++;
		}
	} else if (ch == 'w') {
		if (pos_p2_y > 0) {
			pos_p2_y--;
		}
	} else if (ch == 's') {
		if (pos_p2_y < HEIGHT-PADDLE_HEIGHT) {
			pos_p2_y++;
		}
	}
}

void detect_collision() {
	/* ball collides with upper/lower bounds */
	if (pos_ball_y <= 0 || pos_ball_y >= HEIGHT-1) {
		dir_ball_y *= -1;
	}

	/* ball collides with player1's paddle */
	if (pos_ball_x == 1 && pos_ball_y >= pos_p1_y && pos_ball_y < pos_p1_y + PADDLE_HEIGHT) {
		dir_ball_x *= -1;
	}

	/* ball collides with player2's paddle */
	if (pos_ball_x == WIDTH-2 && pos_ball_y >= pos_p2_y && pos_ball_y < pos_p2_y + PADDLE_HEIGHT) {
		dir_ball_x *= -1;
	}
}

void move_ball() {
	pos_ball_x += dir_ball_x;
	pos_ball_y += dir_ball_y;
}

int detect_ball_out() {
	/* ball is out on left side -> point for player2 */
	if (pos_ball_x <= 0) {
		return 2;
	}

	/* ball is out on right side -> point for player1 */
	if (pos_ball_x >= WIDTH-1) {
		return 1;
	}

	return 0;
}

int play_round() {
	int ball_out;
	int count = 0;
	while( !(ball_out = detect_ball_out()) ) {
		key_processing();
		if(count == 0) {
			move_ball();
			detect_collision();
		}
		print_field();
		count = (count + 1) % 5;
		usleep(20000);
	}
	return ball_out;
}

int main() {
	init();
	place_paddles();
	place_ball(1);

	while(score_p1 < 10 && score_p2 < 10) {
		int round_won = play_round();
		if (round_won == 1) {
			score_p1++;
			place_ball(1);
		} else if (round_won == 2) {
			score_p2++;
			place_ball(-1);
		}
		sleep(1);
		flushinp(); /* keys could've been pressed during sleep ->  emty the input buffer */
	}

	if (score_p1 > score_p2) {
		printw("Player 1 wins!\n");
	} else {
		printw("Player 2 wins!\n");
	}
	refresh();
	sleep(3);

	endwin();
}

Kommentare

Wenn du Anmerkungen zur Aufgabe hast oder Lob und Kritik loswerden möchtest, ist hier die richtige Stelle dafür. Klicke einfach ganz rechts auf "bearbeiten" und schreibe deinen Kommentar direkt ins Wiki. Keine Scheu, es geht nichts kaputt ;)