Diff: Bullet.cpp

Revision:

13:dd1ccafe3972

Parent:

12:170175334df8

diff -r 170175334df8 -r dd1ccafe3972 Bullet.cpp
--- a/Bullet.cpp	Tue May 02 22:25:27 2017 +0000
+++ b/Bullet.cpp	Thu May 04 12:04:59 2017 +0000
@@ -12,71 +12,74 @@
 
 void Bullet::init(Vector2D CarHead)
 {
-    _bullet_x =  CarHead.x;
-    _bullet_y =  CarHead.y + 2; 
+    _bullet_x =  CarHead.x;       // same x value as the car head
+    _bullet_y =  CarHead.y + 2;   // starts from the square right above the car head
     // printf("x=%d y=%d \n",_bullet_x,_bullet_y);
 }
 
 void Bullet::draw(N5110 &lcd)
 {
-  // printf("x=%d y=%d \n",_bullet_x,_bullet_y);              
-  lcd.drawRect(_bullet_x,_bullet_y,2,2,FILL_BLACK);
-  // printf("Crashes 0 \n");
+    // printf("x=%d y=%d \n",_bullet_x,_bullet_y);
+    lcd.drawRect(_bullet_x,_bullet_y,2,2,FILL_BLACK);
+    // printf("Crashes 0 \n");
 }
 
 void Bullet::update(N5110 &lcd,int bulletDirection)
-{   
-    clearBullet(lcd);
+{
+    clear_Bullet(lcd);     // must clear the old bullet before updating otherwise bullets get shifted down with obstacles
     // printf("x=%d y=%d \n",_bullet_x,_bullet_y);
     if(bulletDirection==1) {
-    _bullet_x = _bullet_x;
-    _bullet_y = _bullet_y - 3; 
-    }
-     
-    else if(bulletDirection==2) {
-    _bullet_x = _bullet_x - 3;
-    _bullet_y = _bullet_y - 3; 
+        _bullet_x = _bullet_x;           // Direction straight up
+        _bullet_y = _bullet_y - 3;
+    }     // steps of three
+
+    else if(bulletDirection==2) {        // Direction diagonally left
+        _bullet_x = _bullet_x - 3;
+        _bullet_y = _bullet_y - 3;
+    }      // steps of three
+
+    else if(bulletDirection==3) {        // Direction diagonally right
+        _bullet_x = _bullet_x + 3;
+        _bullet_y = _bullet_y - 3;
+    }       // steps of three
+
+    if ((_bullet_x == -2)) {  // to avoid having _bullet_x = -1,
+        clear_Bullet(lcd);
+        _bullet_x = _bullet_x - 1;
+        _bullet_y = _bullet_y - 1;
     }
-    
-    else if(bulletDirection==3) {
-    _bullet_x = _bullet_x + 3;
-    _bullet_y = _bullet_y - 3; 
-    }
-      // the following piece of code to get around the problem of the game getting stuck when the value of _bullet_x = 1 
-   if ((_bullet_x == -2)) {
-      clearBullet(lcd);
-       _bullet_x = _bullet_x - 1;
-       _bullet_y = _bullet_y - 1; 
-    }
-    destroyObstacles(lcd);
+    destroy_Obstacles(lcd);   // obstacles are destroyed if collision happens between them and bullet
 }
 
-void Bullet::clearBullet(N5110 &lcd)
-{ 
+void Bullet::clear_Bullet(N5110 &lcd)
+{
+    // loop through the bullet pixels
     lcd.setPixel(_bullet_x,_bullet_y,false);       // top left
     lcd.setPixel(_bullet_x,_bullet_y+1,false);     // bottom left
     lcd.setPixel(_bullet_x+1,_bullet_y,false);     // top right
     lcd.setPixel(_bullet_x+1,_bullet_y+1,false);   // bottom right
+    // printf("they are x=%d y=%d \n",_bullet_x,_bullet_y);
 }
 
-void Bullet::destroyObstacles(N5110 &lcd)
-{     
-  // printf("they are x=%d y=%d \n",_bullet_x,_bullet_y);
-  if ((lcd.getPixel(_bullet_x,_bullet_y))     ||  // top left
-     (lcd.getPixel(_bullet_x,_bullet_y+1))    ||  // bottom left
-     (lcd.getPixel(_bullet_x+1,_bullet_y))    ||  // top right
-     (lcd.getPixel(_bullet_x+1,_bullet_y+1))  ||  // bottom right
-     (lcd.getPixel(_bullet_x,_bullet_y-1))    ||  // up left
-     (lcd.getPixel(_bullet_x+1,_bullet_y-1))  ||  // up right
-     (lcd.getPixel(_bullet_x,_bullet_y+2))    ||  // down left
-     (lcd.getPixel(_bullet_x+1,_bullet_y+2)))   { // down right
-         
-         for (int i=1; i<83; i+=1) {
+void Bullet::destroy_Obstacles(N5110 &lcd)
+{
+    // printf("they are x=%d y=%d \n",_bullet_x,_bullet_y);            // loop through the bullet pixels and surrounding pixels
+    if ((lcd.getPixel(_bullet_x,_bullet_y))     ||  // top left                     and check if any is on, so obstacle detected!
+            (lcd.getPixel(_bullet_x,_bullet_y+1))    ||  // bottom left
+            (lcd.getPixel(_bullet_x+1,_bullet_y))    ||  // top right
+            (lcd.getPixel(_bullet_x+1,_bullet_y+1))  ||  // bottom right
+            (lcd.getPixel(_bullet_x,_bullet_y-1))    ||  // up left
+            (lcd.getPixel(_bullet_x+1,_bullet_y-1))  ||  // up right
+            (lcd.getPixel(_bullet_x,_bullet_y+2))    ||  // down left
+            (lcd.getPixel(_bullet_x+1,_bullet_y+2)))   { // down right
+
+        for (int i=1; i<83; i+=1) {
             for (int j=_bullet_y-4; j<_bullet_y+5; j+=1) {
-                lcd.setPixel(i,j,false);   // loop through and turn off pixels around that obstacle
-                }
-                }
-                _bullet_x = -10;   // set the coordinates of the bullet out of the screen
-                _bullet_y = -10;   // so it won't be drawn again until re-initialise the coordinates
-        }
+                lcd.setPixel(i,j,false);   // loop through and set off pixels in and surround that obstacle
+            }                             // we covered wider area than obstacle's width since it
+        }                                 // moves down by more than one increment!
+
+        _bullet_x = -10;   // send it away by setting the coordinates of the bullet out of the screen
+        _bullet_y = -10;   // so it won't be drawn again until re-initialise the bullet's coordinates
+    }
 }
\ No newline at end of file