nInvaders.c

/**
 * nInvaders - a space invaders clone for ncurses
 * Copyright (C) 2002-2003 Dettus
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * homepage: http://ninvaders.sourceforge.net
 * mailto: ninvaders-devel@lists.sourceforge.net
 *
 */


#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include "nInvaders.h"
#include "player.h"
#include "aliens.h"
#include "ufo.h"
#include "highscore.h"

#define FPS 50

int lives;
long score;
int status; // status handled in timer

int weite;
int level;
int skill_level;

#define GAME_LOOP 1
#define GAME_NEXTLEVEL 2
#define GAME_PAUSED 3
#define GAME_OVER 4
#define GAME_EXIT 5
#define GAME_HIGHSCORE 6




/**
 * initialize level: reset attributes of most units
 */
static void initLevel()
{
	playerReset();
	aliensReset();
	ufoReset();
	bunkersReset();
	render();
	drawscore();
}


/**
 * evaluate command line parameters 
 */
static void evaluateCommandLine(int argc, char **argv)
{
	
	// -l : set skill level
	if (argc == 3 && strcmp(argv[1], "-l") == 0) {
		if (argv[2][0] >= '0' && argv[2][0] <= '9') {
			skill_level = argv[2][0] - 48;
		} else {
			argc = 2;
		}
	}

	// -gpl : show GNU GPL
	if (argc == 2 && strcmp(argv[1], "-gpl") == 0) {
		showGpl();
	}

	// wrong command line: show usage
	if (argc == 2 || (argc == 3 && strcmp(argv[1], "-l") != 0)) {
		showVersion();
		showUsage();
		exit(1);
	}
}


static void finish(int sig)
{
        endwin();
	showGplShort();
	
	fprintf(stderr,"\n");
	fprintf(stderr,"\n");
	fprintf(stderr,"=========================================================================\n");
	fprintf(stderr,"\n");
	
	fprintf(stderr,"Final score: %7.7ld, Final level: %2.2d\nFinal rating... ",score,level);
	if (lives>0)
		fprintf(stderr,"Quitter\n\n");
	else if(score<5000)
		fprintf(stderr,"Alien Fodder\n\n");
	else if(score<7500)
		fprintf(stderr,"Easy Target\n\n");
	else if(score<10000)
		fprintf(stderr,"Barely Mediocre\n\n");
	else if(score<12500)
		fprintf(stderr,"Shows Promise\n\n");
	else if(score<15000)
		fprintf(stderr,"Alien Blaster\n\n");
	else if(score<20000)
		fprintf(stderr,"Earth Defender\n\n");
	else if(score>19999)
		fprintf(stderr,"Supreme Protector\n\n");
	
	showVersion();
        exit(0);
}


void drawscore()
{
	statusDisplay(level, score, lives);
}


/**
 * reads input from keyboard and do action
 */
void readInput()
{
	int ch;
	static int lastmove;

	ch = getch();		// get key pressed

	switch (status) {

	case GAME_PAUSED:

		if (ch == 'p') {
			status = GAME_LOOP;
		}
		break;
		       
	case GAME_HIGHSCORE:

		if (ch == ' ') {
			titleScreenClear();
			level = 0;      // reset level
			score = 0;      // reset score
			lives = 3;      // restore lives
			status = GAME_NEXTLEVEL;
		} else if (ch == 'q') {	// quit game
			status = GAME_EXIT;
		} else if (ch == 'a') { //DEBUG: add highscore entry
			addEntry("CHEATER!", 6666, 1);
		}
		break;

	case GAME_OVER:
		break; // don't do anything

	default:

		if (ch == 'l' || ch == KEY_RIGHT) {	// move player right
			if (lastmove == 'l') {
				playerTurboOn();	// enable Turbo
			} else {
				playerTurboOff();	// disable Turbo
			}
			playerMoveRight();		// move player
			lastmove = 'l';			// remember last move for turbo mode
		} else if (ch == 'h' || ch == KEY_LEFT) {	// move player left 
			if (lastmove == 'h') {
				playerTurboOn();	// enable Turbo
			} else {
				playerTurboOff();	// disable Turbo
			}
			playerMoveLeft();		// move player
			lastmove = 'h';			// remember last move for turbo mode
		} else if (ch == 'k' || ch == ' ') {	// shoot missile
			playerLaunchMissile();
		} else if (ch == 'p') {			// pause game until 'p' pressed again
			// set status to game paused
			status = GAME_PAUSED;
		} else if (ch == 'W') {			// cheat: goto next level
			status = GAME_NEXTLEVEL;
		} else if (ch == 'L') {			// cheat: one more live
			lives++;
			drawscore();
		} else if (ch == 'q') {	// quit game
			status = GAME_EXIT;
		} else {		// disable turbo mode if key is not kept pressed
			lastmove = ' ';
		}

	} // switch
	
}
	
	
/**
 * timer
 * this method is executed every 1 / FPS seconds  
 */
void handleTimer()
{
	static int aliens_move_counter = 0; 
	static int aliens_shot_counter = 0;
	static int player_shot_counter = 0;
	static int ufo_move_counter = 0;
	static int title_animation_counter = 0;
	static int game_over_counter = 0;
	
	switch (status) {
		 
	case GAME_NEXTLEVEL:    // go to next level
		
		level++;	// increase level

		initLevel();	// initialize level
		
		aliens_move_counter = 0; 
		aliens_shot_counter = 0;
		player_shot_counter = 0;
		ufo_move_counter = 0;
		
		weite = (shipnum+(skill_level*10)-(level*5)+5)/10;
		
		if (weite < 0) {
			weite = 0;
		}
		
		// change status and start game!
		status = GAME_LOOP;

	case GAME_LOOP:   	 // do game handling
		
		// move aliens			
		if (aliens_move_counter == 0 && aliensMove() == 1) {
			// aliens reached player
			lives = 0;
			status = GAME_OVER;
		}
		
		// move player missile			
		if (player_shot_counter == 0 && playerMoveMissile() == 1) {
			// no aliens left
			status = GAME_NEXTLEVEL;
		}
		
		// move aliens' missiles
		if (aliens_shot_counter == 0 && aliensMissileMove() == 1) {
			// player was hit
			lives--;			// player looses one life
			drawscore();	                // draw score
			playerExplode();		// display some explosion graphics
			if (lives == 0) {		// if no lives left ...
				status = GAME_OVER;		// ... exit game
			}
		}
		
		// move ufo
		if (ufo_move_counter == 0 && ufoShowUfo() == 1) {
			ufoMoveLeft();			// move it one position to the left
		}
		
		
		if (aliens_shot_counter++ >= 5) {aliens_shot_counter=0;}     // speed of alien shot
		if (player_shot_counter++ >= 1) {player_shot_counter=0;}     // speed of player shot
		if (aliens_move_counter++ >= weite) {aliens_move_counter=0;} // speed of aliend
		if (ufo_move_counter++ >= 3) {ufo_move_counter=0;}           // speed of ufo
		
		refreshScreen();
		break;
		
	case GAME_PAUSED:    // game is paused
		break;
		
	case GAME_OVER:      // game over
		if (game_over_counter == 100) {
			battleFieldClear();
			status = GAME_HIGHSCORE;
			game_over_counter = 0;
		} else {
			gameOverDisplay();
			game_over_counter++;
		}
		break;
		
	case GAME_EXIT:      // exit game
		finish(0);
		break;
		
	case GAME_HIGHSCORE: // display highscore
		if (title_animation_counter == 0) {
			titleScreenDisplay();
		}

		if (title_animation_counter++ >= 6) {title_animation_counter = 0;} // speed of animation
		break;
		
	}
}


/**
 * set up timer
 */
void setUpTimer()
{
	struct itimerval myTimer;
	struct sigaction myAction;
	myTimer.it_value.tv_sec = 0;
	myTimer.it_value.tv_usec = 1000000 / FPS;
	myTimer.it_interval.tv_sec = 0;
	myTimer.it_interval.tv_usec = 1000000 / FPS;
	setitimer(ITIMER_REAL, &myTimer, NULL);
	
	myAction.sa_handler = &handleTimer;
	myAction.sa_flags = SA_RESTART;
	sigaction(SIGALRM, &myAction, NULL);
}


int main(int argc, char **argv)
{
 	weite = 0;
	score = 0;
	lives = 3;
	level = 0;
	skill_level = 1;

	evaluateCommandLine(argc, argv);	// evaluate command line parameters
	graphicEngineInit();			// initialize graphic engine
	
	// set up timer/ game handling
	setUpTimer();

	// load highscore and set start status
	highscore = readHighScore();
	status = GAME_HIGHSCORE;

	// read keyboard input
	do {
		// do movements and key-checking
		readInput();
	} while (0 == 0);

	// save highscore
	writeHighScore(highscore);
	
	return 0;
}


void doScoring(int alienType)
{
	int points[4] = {500, 200, 150, 100};   	// 0: ufo, 1:red, 2:green, 3:blue
	
	score += points[alienType];		// every alien type does different scoring points
	
	// every 6000 pts player gets a new live
	if (score % 6000 == 0){
		lives++;
	}
	
	drawscore();	// display score
}