c/ninvaders-0.1.1/ufo.c

   1 /**
   2  * nInvaders - a space invaders clone for ncurses
   3  * Copyright (C) 2002-2003 Dettus
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  *
  19  * homepage: http://ninvaders.sourceforge.net
  20  * mailto: ninvaders-devel@lists.sourceforge.net
  21  *
  22  */
  23
  24
  25 #include "ufo.h"
  26 #include "aliens.h"
  27 #include "nInvaders.h"
  28
  29 static int fShowUfo = 0;
  30
  31 /**
  32  * initialize ufo attributes
  33  */
  34 void ufoReset()
  35 {
  36         ufoClear(ufo.posX, ufo.posY);   // clear old position of player
  37
  38         fShowUfo = 0;                   // do not show ufo
  39         ufo.posY = UFOPOSY;             // set vertical Position
  40         ufo.posX = SCREENWIDTH - UFOWIDTH;// set horizontal Position
  41 }
  42
  43 /**
  44  * move ufo horizontally to position posX
  45  */
  46 static void ufoMove(int posX)
  47 {
  48         ufoClear(ufo.posX, ufo.posY);   // clear sprite
  49         ufo.posX = posX;
  50         ufoRefresh();
  51         ufoDisplay(ufo.posX, ufo.posY);
  52 }
  53
  54
  55 /**
  56  * move ufo and check if it reached the left screen border
  57  */
  58 void ufoMoveLeft()
  59 {
  60         // check if space between ufo and screen border is big enough
  61         if (ufo.posX > 1) {
  62                 // desired movement is possible
  63                 ufoMove(ufo.posX - 1);
  64         } else {
  65                 ufoReset();
  66         }
  67 }
  68
  69 /**
  70  * check if the first screen line is free for the ufo and
  71  * display it randomly
  72  */
  73 int ufoShowUfo()
  74 {
  75         if (aliens.posY > 0 && fShowUfo == 0) { // aliens one line down
  76                 if ((random() % 200) == 0) {
  77                         fShowUfo = 1;
  78                 }
  79         }
  80
  81         return fShowUfo;
  82 }
  83
  84 /**
  85  * check if ufo was hit by player and delete it from screen
  86  */
  87 int ufoHitCheck(int shotX, int shotY)
  88 {
  89         int fUfoWasHit = 0;
  90
  91         // if shot reached vertikal position of ufo
  92         if (shotY == UFOPOSY) {
  93                 // if shot hits ufo
  94                 if (shotX >= ufo.posX && shotX <= ufo.posX + UFOWIDTH -1) {
  95                         ufoReset();
  96                         fUfoWasHit = 1;
  97                 }
  98         }
  99
 100         return fUfoWasHit;
 101 }