Diff: Bullet/bullet.h

Revision:

21:edfeb289b21f

Parent:

17:7bc7127782e4

--- a/Bullet/bullet.h	Thu Oct 29 02:21:11 2015 +0000
+++ b/Bullet/bullet.h	Thu Oct 29 03:56:30 2015 +0000
@@ -3,22 +3,50 @@
 
 #include "tank.h"
 
+#define BULLET_NO_COLLISION -1
+#define BULLET_OFF_SCREEN   -2
+
 class Bullet{
     public:
-        int x0;
-        int y0;
-        float vx0;
-        float vy0;
-        int x;
-        int y;
+        
+        // (x0, y0) is the position of the bullet at the start of its trajectory.
+        int x0, y0;
+        
+        // The components of the bullet's initial velocity.
+        float vx0, vy0;
+        
+        // The current position of the bullet.
+        int x, y;
+        
+        // How fast is the bullet?
         int speed;
+        
+        // Keep track of the time since the bullet was shot.
         float time;
+        
+        // Keep track of whether the bullet is currently in flight.
+        // If it is in_flight, update its position. Otherwise, ignore it.
+        // Set in_flight when the bullet is shot.
+        // Reset in_flight when the bullet hits something.
         bool in_flight;
         
+        // Keep a pointer to the tank that shot this bullet. You'll need
+        // it to access information about the tank.
         Tank* tank;
         
+        // Create a bullet!
         Bullet(Tank* t);
+        
+        // Shoot the bullet!
         void shoot(void);
+        
+        // given a time delta, calculate the new (x, y) coords of the bullet.
+        void update_position(float dt);
+        
+        // Once per frame, plug in the time since the last frame.
+        // Clear the old bullet and redraw it in the new place.
+        // Do collision detection here. Return a code describing what has
+        // (or hasn't) been hit.
         int time_step(float dt);    
 };