Pong - 2 Player Game

gistfile1.cpp

#include <allegro.h>

#define DOWN_RIGHT 0
#define UP_RIGHT 1
#define DOWN_LEFT 2
#define UP_LEFT 3

void moveBall(void);
void reserveVerticalDirection(void);
void reserveHorizontalDirection(void);
void respondToKeyboard(void);
void delay();

volatile int ball_x;
volatile int ball_y;
volatile double barL_y;
volatile double barR_y;
volatile int scoreL;
volatile int scoreR;
volatile int direction;

BITMAP *ball;
BITMAP *bar;
BITMAP *buffer;
FONT *fnt;

int main()
{
   allegro_init();
   install_keyboard();
   install_timer();
   set_color_depth(32);
   set_gfx_mode(GFX_AUTODETECT_WINDOWED, 640, 480, 0, 0);
   ball = load_bitmap("ball.bmp", NULL);
   bar = load_bitmap("bar.bmp", NULL);
   fnt = load_font("pFont.pcx", NULL, NULL);
   buffer = create_bitmap(SCREEN_W, SCREEN_H);
   set_pallete(desktop_pallete);
   ball_x = SCREEN_W / 2;
   ball_y = SCREEN_H / 2;
   barL_y = SCREEN_H / 2;
   barR_y = SCREEN_H / 2;
   scoreL = 0;
   scoreR = 0;
   srand(time(NULL));
   direction = rand() % 4;
   install_int(moveBall, 3);
   install_int(respondToKeyboard, 10);

   while (!key[KEY_ESC])
   {
       clear_to_color(buffer, makecol(255, 255, 255));
       blit(ball, buffer, 0, 0, ball_x, ball_y, ball->w, ball->h);
       blit(bar, buffer, 0, 0, 0, barL_y, bar->w, bar->h);
       blit(bar, buffer, 0, 0, 620, barR_y, bar->w, bar->h);
       line(buffer, 0, 30, 640, 30, makecol(0, 0, 0));
       textprintf_ex(buffer, font, 75, 0, makecol(0, 0, 0), -1, "Left Player Score : %d", scoreL);
       textprintf_ex(buffer, font, 400, 0, makecol(0, 0, 0), -1, "Right Player Score : %d", scoreR);
       textprintf_ex(buffer, font, 200, 20, makecol(0, 0, 0), -1, "Created by C-TOS (CyB3r-t3Rr0r)");
        // vsync();
       blit(buffer, screen, 0, 0, 0, 0, buffer->w, buffer->h);
       clear_bitmap(buffer);
   }
   remove_int(moveBall);
   remove_int(respondToKeyboard);
   destroy_bitmap(ball);
   destroy_bitmap(bar);
   destroy_bitmap(buffer);
   destroy_font(fnt);
   return 0;
}
END_OF_MAIN()

void moveBall()
{
    switch (direction)
    {
        case DOWN_RIGHT:
        ++ball_x;
        ++ball_y;
        break;
        case UP_RIGHT:
        ++ball_x;
        --ball_y;
        break;
        case DOWN_LEFT:
        --ball_x;
        ++ball_y;
        break;
        case UP_LEFT:
        --ball_x;
        --ball_y;
        break;
    }
    if (ball_y <= 35 || ball_y >= 448)
    reserveVerticalDirection();
   /*
    if (ball_x <= 0 || ball_x >= 608)
    reserveHorizontalDirection();
    */
    if (ball_x < 20 && (direction == DOWN_LEFT || direction == UP_LEFT))
    {
        if (ball_y > (barL_y - 39) && ball_y < (barL_y + 99))
        reserveHorizontalDirection();
        else if (ball_x <= -20)
        {
            ++scoreR;
            ball_x = SCREEN_W / 2;
            ball_y = SCREEN_H / 2;
            direction = rand() % 4;
            delay();
        }
    }
    if (ball_x > 580 && (direction == DOWN_RIGHT || direction == UP_RIGHT))
    {
        if (ball_y > (barR_y - 39) && ball_y < (barR_y + 99))
        reserveHorizontalDirection();
        else if (ball_x >= 620)
        {
            ++scoreL;
            ball_x = SCREEN_W / 2;
            ball_y = SCREEN_H / 2;
            direction = rand() % 4;
            delay();
        }
    }
}

void reserveVerticalDirection()
{
    if ((direction % 2) == 0)
    ++direction;
    else
    --direction;
}

void reserveHorizontalDirection()
{
    direction = (direction + 2) % 4;
}

void respondToKeyboard()
{
    if (key[KEY_A])
    barL_y -= 3;
    if (key[KEY_Z])
    barL_y += 3;

    if (key[KEY_UP])
    barR_y -= 3;
    if (key[KEY_DOWN])
    barR_y += 3;

    if (barL_y < 30)
    barL_y = 30;
    else if (barL_y > 380)
    barL_y = 380;
    if (barR_y < 30)
    barR_y = 30;
    else if (barR_y > 380)
    barR_y = 380;
}

void delay()
{
    long int i;
    for (i = 123456789; i >= 0; i--);
}