5 files changed, 263 insertions(+), 0 deletions(-)

A .gitignore
A Makefile
A README.md
A good.png
A pong.c

@@ 1,1 @@
+pong

@@ 1,7 @@
+.PHONY : all clean
+
+all : 
+	gcc -std=c99 pong.c -lm -lncurses `pkg-config --cflags ncurses` -o pong
+
+clean :
+	rm pong

@@ 1,31 @@
+# pong
+
+Simple pong replica for the terminal; written in C. 
+
+![Picture of the game while running.](good.png)
+
+## How to run
+
+Requires ncurses.
+
+```bash
+make ./pong 
+```
+
+## Customization
+
+To edit the colors, see the `#defines` for `*_ATTRS` and look into the `setup`
+to `init_pair`.
+
+To edit the characters used for drawing the ball and pads, change `BALL` and
+`PAD`.
+
+To alter the size of the game field, adjust `WIDTH` and `HEIGHT`.
+
+To change the pad size, edit `PAD_SIZE`.
+
+To change the time between frames, modify `DELTA`.
+
+To change the ball's velocity, set `velocity`. To change the ball's starting
+angle, use `set_ball_angle(<angle>)` at the end of `setup`.
+

@@ 1,224 @@
+#include <ncurses.h>
+#include <math.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#define WIDTH 30
+#define HEIGHT 10
+#define PAD_SIZE 4
+#define BALL "O"
+#define PAD "#"
+#define BLUE 1
+#define RED 2
+#define YELLOW 3
+#define BALL_ATTRS A_BOLD | COLOR_PAIR(YELLOW)
+#define PAD_P1_ATTRS A_BOLD | COLOR_PAIR(BLUE)
+#define PAD_P2_ATTRS A_BOLD | COLOR_PAIR(RED)
+#define PI 3.1415926535
+#define DELTA 50000
+#define UP -1
+#define DOWN 1
+
+enum game_state {
+	GS_OK,
+	GS_WIN_P1,
+	GS_WIN_P2,
+} gs = GS_OK;
+
+struct vec2_d {
+	double x, y;
+};
+
+struct vec2_i {
+	int x, y;
+};
+
+struct ball {
+	struct vec2_d pos;
+	struct vec2_d dir;
+	double angle;
+} ball;
+
+WINDOW* screen = NULL;
+struct vec2_i p1_pad, p2_pad;
+double velocity = 0.5;
+
+int between(int low, int high, int x) {
+	return x >= low && x <= high;
+}
+
+void set_ball_angle(double radians) {
+	ball.dir.x = cos(radians);
+	ball.dir.y = sin(radians);
+	ball.angle = radians;
+}
+
+void draw_pad(int p) {
+	struct vec2_i *pad = NULL;
+	pad = (p == 1 ? &p1_pad : &p2_pad);
+
+	p == 1 ? wattron(screen, PAD_P1_ATTRS) : wattron(screen, PAD_P2_ATTRS);
+	for (int i = 0; i < PAD_SIZE; i++) {
+		mvwprintw(screen, pad->y + i, pad->x, "%s", PAD);
+	}
+	p == 1 ? wattroff(screen, PAD_P1_ATTRS) : wattroff(screen, PAD_P2_ATTRS);
+}
+
+void move_pad(int p, int dir) {
+	struct vec2_i *pad = NULL;
+	pad = (p == 1 ? &p1_pad : &p2_pad);
+
+	if (dir == UP)
+		mvwprintw(screen, pad->y + PAD_SIZE - 1, pad->x, " ");
+	else
+		mvwprintw(screen, pad->y, pad->x, " ");
+
+	pad->y += dir;
+	if (pad->y <= 0)
+		pad->y = 1;
+	else if (pad->y >= HEIGHT - PAD_SIZE - 1)
+		pad->y = HEIGHT - PAD_SIZE - 1;
+
+	draw_pad(p);
+}
+
+void move_ball() {
+	int collided_pad = FALSE, collided_wall = FALSE;
+	struct vec2_d old_pos = ball.pos;
+
+	ball.pos.x += ball.dir.x * velocity;
+	ball.pos.y -= ball.dir.y * velocity;
+
+	if ((int)ball.pos.y <= 0) {
+		collided_wall = TRUE;
+		ball.pos.y = 1.0;
+	} else if ((int)ball.pos.y >= HEIGHT - 1) {
+		collided_wall = TRUE;
+		ball.pos.y = HEIGHT - 2;
+	}
+	
+	if (collided_wall) {
+		set_ball_angle(0 - ball.angle);
+		gs = GS_OK;
+		goto draw;
+	}
+	
+	if (((int)ball.pos.x == p1_pad.x && between(p1_pad.y, p1_pad.y + PAD_SIZE - 1, ball.pos.y))) {
+		collided_pad = TRUE;
+		ball.pos.x = p1_pad.x + 1.0;
+	} else if ((int)ball.pos.x == p2_pad.x && between(p2_pad.y, p2_pad.y + PAD_SIZE - 1, ball.pos.y)) {
+		collided_pad = TRUE;
+		ball.pos.x = p2_pad.x - 1.0;
+	}
+
+	if (collided_pad) {
+		set_ball_angle(PI - ball.angle);
+		gs = GS_OK;
+		goto draw;
+	}
+
+	if ((int)ball.pos.x <= 0) {
+		gs = GS_WIN_P2;
+		return;
+	} else if ((int)ball.pos.x >= WIDTH - 1) {
+		gs = GS_WIN_P1;
+		return;
+	} else {
+		gs = GS_OK;
+	}
+
+draw:
+	mvwprintw(screen, (int)old_pos.y, (int)old_pos.x, " ");
+	wattron(screen, BALL_ATTRS);
+	mvwprintw(screen, (int)ball.pos.y, (int)ball.pos.x, "%s", BALL);
+	wattroff(screen, BALL_ATTRS);
+}
+
+void run() {
+	int should_run = TRUE, key;
+
+	draw_pad(1);
+	draw_pad(2);
+
+	while (should_run) {
+		key = wgetch(screen);
+		switch (key) {
+			case 'w': case 'W':
+				move_pad(1, UP);
+				break;
+			case 's': case 'S':
+				move_pad(1, DOWN);
+				break;
+			case KEY_UP:
+				move_pad(2, UP);
+				break;
+			case KEY_DOWN:
+				move_pad(2, DOWN);
+				break;
+			case 'q': case 'Q':
+				should_run = FALSE;
+				break;
+		}
+		move_ball();
+		
+		box(screen, 0, 0);
+		wrefresh(screen);
+
+		if (gs != GS_OK)
+			should_run = false;
+
+		usleep(DELTA);
+	}
+}
+
+void setup() {
+	initscr();
+	cbreak();
+	noecho();
+	keypad(stdscr, TRUE);
+	curs_set(FALSE);
+	start_color();
+	init_pair(BLUE, COLOR_BLUE, COLOR_BLACK);
+	init_pair(RED, COLOR_RED, COLOR_BLACK);
+	init_pair(YELLOW, COLOR_YELLOW, COLOR_BLACK);
+	
+	refresh();
+	
+	int max_x, max_y, screen_x, screen_y;
+	getmaxyx(stdscr, max_y, max_x);
+
+	screen_x = (max_x - WIDTH) / 2;
+	screen_y = (max_y - HEIGHT) / 2;
+
+	screen = newwin(HEIGHT, WIDTH, screen_y, screen_x);
+	box(screen, 0, 0);
+	nodelay(screen, TRUE);
+	keypad(screen, TRUE);
+	wrefresh(screen);
+
+	p1_pad.x = 1.;
+	p1_pad.y = 1.;
+	p2_pad.x = WIDTH - 2.;
+	p2_pad.y = 1.;
+	ball.pos.x = (double)(WIDTH / 2);
+	ball.pos.y = (double)(HEIGHT / 2);
+	set_ball_angle(PI/3);
+}
+
+void cleanup() {
+	endwin();
+}
+
+int main() {
+	setup();
+	run();
+	cleanup();
+
+	if (gs == GS_WIN_P1)
+		puts("Player 1 wins!\n");
+	else if (gs == GS_WIN_P2)
+		puts("Player 2 wins!\n");
+	else
+		puts("Game ended.\n");
+	return 0;
+}