Pong.c

gistfile1.txt

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <conio.h>
#include <string.h>

void print_at_xy(int x, int y, char *val);
void display_score();
void init();
int zero_lives();
void set_game_state_over();
void update_ball();
char get_input();
void update_player(char);
int ball_collides_with_bat();
void increment_score();
int ball_is_out_bounds();
void decrement_lives();
void draw();
void clean_up();
int ball_collides_with_wall();
int ball_collides_with_ceiling();
void capture_previous_pos();
void clear_screen();
void reset_ball();
void display_message(const char *);

HANDLE _output_handle;

void hidecursor()
{
   _output_handle = GetStdHandle(STD_OUTPUT_HANDLE);
   CONSOLE_CURSOR_INFO info;
   info.dwSize = 100;
   info.bVisible = FALSE;
   SetConsoleCursorInfo(_output_handle, &info);
}

int SCREEN_WIDTH;
int SCREEN_HEIGHT;
int bat_y;
int bat_x;
int BAT_WIDTH;
int BAT_SPEED;
int ball_x;
int ball_y;
int lives;
int game_state;
int GAME_STATE_OVER;
int GAME_STATE_PLAYING;
int GOAL_POINTS;
int delta_x;
int delta_y;
int score;
char ball_string[2];
char bat_string[20];
char game_over_string[30];

int prev_bat_x;
int prev_bat_y;
int prev_ball_x;
int prev_ball_y;


int main(){

    init();
    printf("\ninit");
    system("@cls||clear");

    //1000/30
    //game loop
    while(1){

        clear_screen();
        
        if(zero_lives()){
            set_game_state_over();
            print_at_xy(SCREEN_WIDTH/2 - 10, SCREEN_HEIGHT/2, game_over_string);
            display_message("Enter 'q' to quit...");
        }

        char ch = get_input();

        //clear screen and quit
        if(game_state == GAME_STATE_OVER && ch == 'q'){
            system("@cls||clear");
            break;
        }

        if(game_state == GAME_STATE_PLAYING){
            clear_screen();
            capture_previous_pos();
            update_ball();            
            update_player(ch);

            if(ball_collides_with_wall()){
                delta_x *= -1;
            }

            if(ball_collides_with_ceiling()){
                delta_y *= -1;
            }

            if(ball_collides_with_bat()){
                
                display_message("OH YEAH!!!");
                if(delta_y > 0){
                    delta_y *= -1;
                }
                
                increment_score();
            }
            if(ball_is_out_bounds()){
                decrement_lives();
                reset_ball();
                display_message("OOPSIE!!");
            }

            draw();
            Sleep(100);
        }
    }

    clean_up();
}


void init(){
    score = 0;
    lives = 3;
    GOAL_POINTS = 10;
    GAME_STATE_OVER = 1;
    GAME_STATE_PLAYING = 2;
    SCREEN_WIDTH = 40;
    SCREEN_HEIGHT = 20;
    bat_y = SCREEN_HEIGHT;
    BAT_WIDTH = 8;
    BAT_SPEED = 2;
    bat_x = (SCREEN_WIDTH/2) - (BAT_WIDTH/2);
    delta_x = 1;
    delta_y = -1;    
    ball_x = (SCREEN_WIDTH/2);
    ball_y = SCREEN_HEIGHT;
    game_state = GAME_STATE_PLAYING;
    strcpy(bat_string, "========");
    strcpy(ball_string, "O");
    strcpy(game_over_string, "GAME OVER");
    hidecursor();

    prev_bat_x = bat_x;
    prev_bat_y = bat_y;
    prev_ball_x = ball_x;
    prev_ball_y = ball_y;    
}

void reset_ball(){
    ball_x = SCREEN_WIDTH/2;
    ball_y = SCREEN_HEIGHT;
    delta_x = -1;
    delta_y = -1;
}

int zero_lives(){
    if(lives == 0){
        return 1;
    }
    return 0;
}

void set_game_state_over(){
    game_state = GAME_STATE_OVER;
}

void update_ball(){
    ball_x += delta_x;
    ball_y += delta_y;
}

char get_input(){
    char ch = 0;

    if(kbhit()){
        ch = getch();
    }

    return ch;
}

void update_player(char ch){
    if(ch == 'j' || ch == 'J')
    {
        bat_x -= BAT_SPEED;
    }
    else if(ch == 'k' || ch =='K'){
        bat_x += BAT_SPEED;
    }

    if(bat_x < 0){
        bat_x = 0;
    }
    if(bat_x + BAT_WIDTH > SCREEN_WIDTH){
        bat_x = SCREEN_WIDTH - BAT_WIDTH;
    }
}

int ball_collides_with_bat(){
    if(bat_y == ball_y || (bat_y == ball_y-1)){
        if(bat_x <= ball_x && (bat_x + BAT_WIDTH) >= ball_x){
            return 1;
        }
    }

    return 0;
}

void increment_score(){
    score += GOAL_POINTS;
}

int ball_is_out_bounds(){
    if(ball_y > SCREEN_HEIGHT + 3){
        return 1;
    }

    return 0;
}

void decrement_lives(){
    lives--;
}

void draw(){
    print_at_xy(ball_x, ball_y, ball_string);
    print_at_xy(bat_x, bat_y, bat_string);
    display_score();
}

void print_at_xy(int x, int y, char *val)
{
  COORD coord;
  coord.X = x;
  coord.Y = y;
  SetConsoleCursorPosition(_output_handle, coord);
  printf("%s", (const char *)val);
  fflush(stdout);
}

void display_score(){
    char buffer[50] = {0};
    sprintf(buffer, "SCORE: %4d LIVES: %d", score, lives);
    print_at_xy(0, 0, buffer);
}

int ball_collides_with_wall(){
    return ball_x <= 0 || (ball_x-1) >= SCREEN_WIDTH;
}

int ball_collides_with_ceiling(){
    return ball_y <= 0;
}

void capture_previous_pos(){
    prev_ball_x = ball_x;
    prev_ball_y = ball_y;
    prev_bat_x = bat_x;
    prev_bat_y = bat_y;
}

void clear_screen(){
    char buffer[] = "                      ";
    print_at_xy(prev_ball_x, prev_ball_y, buffer);
    print_at_xy(prev_bat_x, prev_bat_y, buffer);
    print_at_xy(0, 0, buffer);    
}

void display_message(const char *message){
    char buffer[100] = {0};
    strcpy(buffer, message);
    print_at_xy(SCREEN_WIDTH/2 - strlen(message)/2, 
                SCREEN_HEIGHT/2 - 1, buffer);
}

void clean_up(){
    printf("Thanks for playing.");
}