Diff: Ball/Ball.cpp

Revision:

85:6b21dc88f2fc

Parent:

76:52410264a72d

Child:

91:c01a736fb0d9

--- a/Ball/Ball.cpp	Mon May 06 17:49:36 2019 +0000
+++ b/Ball/Ball.cpp	Mon May 06 18:41:24 2019 +0000
@@ -12,60 +12,54 @@
 
 void Ball::init(int size,int speed, int x)
 {
-    _size = size;
+    _size = size; // size of the ball
 
-    _x = x;
-    _y = HEIGHT - _size/2 - 4;
+    _x = x;   // init position of the ball will be at the centre of the paddle
+    _y = HEIGHT - _size/2 - 4; // fixed y init position
 
     srand(time(NULL));
-    int direction = rand() % 4; // randomise initial direction. 
+    int direction = rand() % 2; // randomise initial direction. 
 
-    // 4 possibilities. Get random modulo and set velocities accordingly
+    // 2 directions, both directed upwards (N) from the paddle
     if (direction == 0) {
-        _velocity.x = speed;
-        _velocity.y = -speed;
-    } else if (direction == 1) {
-        _velocity.x = -speed;
-        _velocity.y = -speed;
-    } else if (direction == 2) {
-        _velocity.x = speed;
-        _velocity.y = -speed;
+        _velocity.x = speed; // direction = E
+        _velocity.y = -speed; // direction = N
     } else {
-        _velocity.x = -speed;
-        _velocity.y = -speed;
+        _velocity.x = -speed; // direction = W
+        _velocity.y = -speed; // direction = N
     }
 }
 
-void Ball::draw(N5110 &lcd)
+void Ball::draw(N5110 &lcd)  // draw the ball at the specified location
 {
     lcd.drawRect(_x,_y,_size,_size,FILL_BLACK);
 }
 
-void Ball::update()
+void Ball::update()  // update the ball's position, based on its current velocity
 {
     _x += _velocity.x;
     _y += _velocity.y;
 }
 
-void Ball::set_velocity(Vector2D v)
+void Ball::set_velocity(Vector2D v) // set the velocity in its x/y directions (used for collision velocity correction)
 {
     _velocity.x = v.x;
     _velocity.y = v.y;
 }
 
-Vector2D Ball::get_velocity()
+Vector2D Ball::get_velocity() // retrieve the ball's current velocities
 {
     Vector2D v = {_velocity.x,_velocity.y};
     return v;
 }
 
-Vector2D Ball::get_pos()
+Vector2D Ball::get_pos() // retrieve the ball's current coordinates
 {
     Vector2D p = {_x,_y};
     return p;
 }
 
-void Ball::set_pos(Vector2D p)
+void Ball::set_pos(Vector2D p)  // set the ball's coordinates (used for collision velocity correction)
 {
     _x = p.x;
     _y = p.y;