ELEC2645 (2019/20)
Joshua O'hara 201291390
Dependencies: mbed
Diff: Alien/Alien.cpp
- Revision:
- 43:1ac200335a68
- Parent:
- 38:6f50b548226e
- Child:
- 44:3b904d25ee12
--- a/Alien/Alien.cpp Tue May 26 13:10:12 2020 +0000
+++ b/Alien/Alien.cpp Tue May 26 15:13:10 2020 +0000
@@ -2,15 +2,15 @@
void Alien::init(int x, int y, int size, int level) {
- _alive = true;
- _shoot = false;
- _powerup = true;
- _create_powerup = false;
- _x = x;
+ _alive = true; //alien life is true
+ _shoot = false; //set shoot flag to false to be turned true by flag set function
+ _powerup = true; //set powerup flag to true, will be turned to false when alien dies so alien can only drop 1 powerup
+ _create_powerup = false; //create powerup flag false as no powerup has been created
+ _x = x; //set starting position
_y = y;
- _size = size;
- _speed = 1 + 0.3 * level;
- _alien_bullet_vector.init();
+ _size = size; //set size (width)
+ _speed = 1 + 0.3 * level; //set speed in x diretion, increases with level to make game get harder
+ _alien_bullet_vector.init(); //initialise the alien's vector of bullets
// printf(" speed = %2d ",Speed);
}
@@ -18,60 +18,58 @@
void Alien::render(N5110 &lcd)
{
if(_alive == true){
- lcd.drawLine(_x,_y+1,_x+_size-1,_y+1,1);
+ lcd.drawLine(_x,_y+1,_x+_size-1,_y+1,1); //draw alien (traingular pointing down)
lcd.setPixel(_x,_y,true);
lcd.setPixel(_x+_size-1,_y,true);
lcd.setPixel(_x+_size/2,_y+2,true);
_alien_bullet_vector.render(lcd);
}
- if(_create_powerup == true){
- _powerup_vector[0].render(lcd);
+ if(_create_powerup == true){ //draw powerup if one has been created
+ _powerup_vector[0].render(lcd); //we only need to check 0th powerup in vector as only one can be added to vector per alien
//printf("powerup render");
}
}
Vector2D Alien::get_position()
{
- Vector2D p = {_x,_y};
+ Vector2D p = {_x,_y}; //returns a 2d vector of the alien's position
return p;
}
void Alien::update(int step_x, int remainder_x, Gamepad &pad, int counter, int level)
{
- _x+=_speed;
- int counter_ = counter;
- int step_x_ = step_x;
- int remainder_x_ = remainder_x;
- if (_x < 1 + remainder_x_*step_x_) {
- _x = 1 + remainder_x_*step_x_;
- _speed = -_speed;
- _y = _y + 2;
+ _x+=_speed; //change xposition according to speed
+ int counter_ = counter; //copy counter value to function variable
+ int step_x_ = step_x; //copy step value to function variable
+ int remainder_x_ = remainder_x; //copy remainder value to function variable
+ if (_x < 1 + remainder_x_*step_x_) { //make alien change directions and move down screen if alien armada reaches edge of the screen
+ _x = 1 + remainder_x_*step_x_; //using the remainder_x_ value (which shows this alien's position in the row, e.g 3 from left)
+ _speed = -_speed; //and the distance between alien's, we can calculate at which point on the screen each alien
+ _y = _y + 2; //should change directions
}
- if (_x > WIDTH - _size - 1 - (4-remainder_x_)*step_x_) {
+ if (_x > WIDTH - _size - 1 - (4-remainder_x_)*step_x_) { //same process but for other side of screen
_x = WIDTH - _size - 1 - (4-remainder_x_)*step_x_;
_speed = -_speed;
_y = _y + 2;
}
- shoot_flag_set(counter_,level); //runs flag set function
- _alien_bullet_vector.update(_x,_y,_shoot);
- _shoot = false;
+ shoot_flag_set(counter_,level); //runs flag set function
+ _alien_bullet_vector.update(_x,_y,_shoot); //updates the vector of alien bullets
+ _shoot = false; //sets shoot flag to false in case alien shot on this loop
- if(_powerup == true){
- powerup_flag_set();
- if(_create_powerup == true){
- PowerUp new_powerup_;
- new_powerup_.init(_x,_y,3);
- _powerup_vector.push_back(new_powerup_);
+ if(_powerup == true){ //runs the powerup flag set to determine if the create powerup flag will be set to true upon alien death
+ create_powerup_flag_set(); //powerup flag set function will not run if alien is still alive so create powerup flag cannot be set to true
+ if(_create_powerup == true){ //powerup flag will be set to false after alien dies so this block of code is only run 1 time after death
+ PowerUp new_powerup_; //creating a new powerup only oncre
+ new_powerup_.init(_x,_y,3); //initialising powerup
+ _powerup_vector.push_back(new_powerup_); //adding powerup to a vector for use outside of function
//printf(" powerup created ");
}
}
- if(_create_powerup == true){
- _powerup_vector[0].update();
+ if(_create_powerup == true){ //updates powerup if one has been created
+ _powerup_vector[0].update(); //we only need to check 0th powerup in vector as only one can be added to vector per alien
//printf("powerup update");
}
-
-
//printf(" speed = %2d ",Speed);
}
@@ -89,8 +87,8 @@
void Alien::shoot_flag_set(int counter, int level)
{
int counter_ = counter;
- if(counter_%8 == 1){ //sets shoot to true every 8 main loop iterations and if a random number falls below a decided limit and the alien is alive
- int r_ = rand()%20;
+ if(counter_%8 == 1){ //sets shoot to true every 8 main loop iterations (1 1/3 secs) and if a random number falls below a decided limit and the alien is alive
+ int r_ = rand()%20; //test a random number so alien doesnt shoot every 8 loops
if((r_ < level+1)&& //limit increases with level, so aliens will shoot more as game goes on
(_alive == true)) {
_shoot = true;
@@ -109,11 +107,11 @@
_alien_bullet_vector.set_hit(i,hit); //sets the hit value of bullet i in this aliens bullet vector
}
-void Alien::powerup_flag_set()
+void Alien::create_powerup_flag_set()
{
- if(_alive == false){
- _powerup = false;
- int rand_ = rand()%6;
+ if(_alive == false){ //check to see if ship has died
+ _powerup = false; //set powerup flag to false as we only want to create 1 powerup per alien when alien dies
+ int rand_ = rand()%6; //test a random number to set create powerup flag, as we dont want every alien death to yield a powerup drop
if(rand_ == 0){
_create_powerup = true;
}
@@ -123,24 +121,24 @@
Vector2D Alien::get_powerup_position()
{
Vector2D v;
- if(_create_powerup == true){
- v = _powerup_vector[0].get_position();
+ if(_create_powerup == true){ //returns powerup position if powerup has been created
+ v = _powerup_vector[0].get_position(); //we only need to check 0th powerup in vector as only one can be added to vector per alien
}
return v;
}
void Alien::set_powerup_hit(bool x)
{
- if(_create_powerup == true){
- _powerup_vector[0].set_hit(x);
+ if(_create_powerup == true){ //sets powerup hit if powerup has been created
+ _powerup_vector[0].set_hit(x); //we only need to check 0th powerup in vector as only one can be added to vector per alien
}
}
bool Alien::get_powerup_hit()
{
bool x;
- if(_create_powerup == true){
- x = _powerup_vector[0].get_hit();
+ if(_create_powerup == true){ //returns powerup hit value if powerup has been created
+ x = _powerup_vector[0].get_hit(); //we only need to check 0th powerup in vector as only one can be added to vector per alien
}
return x;
}