File content as of revision 22:d2969236b4f3:

#include "Engine.h"

// Reference for the technique used to generate random numbers.
// [1] "rand" cplusplus. [Online] Available: http://www.cplusplus.com/reference/cstdlib/rand/ [Accessed: 22 April 2019].  

// Buffer to print updated score.
char buffer[14];   

// Constructor and destructor.
Engine::Engine() {} 

Engine::~Engine() {}

void Engine::init() {
  // 
  reset_skater();
  reset_engine();
  srand(time(NULL));  // Set up for generating random numbers, [1].
}

void Engine::check_reset(N5110 &lcd, Gamepad &gamepad) {
  // If reset flag is true, end and restart the game.
  if (_skater.get_reset_flag()) {
    execute_dying_sequence(lcd, gamepad);
    wait(1);
    reset_skater();
    reset_engine();
  }
}

void Engine::execute_dying_sequence(N5110 &lcd, Gamepad &gamepad) {
  wait(1);
  lcd.clear();
  for (int i = 0; i < 40; i = i + 8) {  // Counter for y direction, sweeps top 
  // to bottom.
    for (int j = 0; j < 84; j++) {  // Counter for x direction, sweeps L to R 
      lcd.setPixel(j,i,true);
      lcd.setPixel(i,j,true);
      lcd.printString("TRY AGAIN",30,5);  
      lcd.refresh();
      gamepad.tone(int(1099 - 15.4*j - 1.2*i), 0.05);  // Frequnecy of tone is 
      // dependent on counters. 
      wait(0.001);
      sprintf(buffer,"%2d",_player_score); 
      lcd.printString(buffer,0,5);
    }  
  }
}

void Engine::reset_skater() {
  _skater_direction = Left;
  _start_platform_flag = true;  // For printing start text in EngineController
  _skater.set_reset_flag(false);
  _moving_counter = 0;
  _jump_counter = 20; 
  _fall_flag = false;
}  

void Engine::reset_engine() {
  _input.coord.x = 0;
  _input.coord.y = 0;
  _input.A_flag = false;
  _lower_platforms.init(40);  // 40 is the platform y coord.
  _upper_platforms.init(22);  // 22 is the platform y coord.
  _coin.init();
  _fire.init();
  _coin_collision_flag = false;
  _player_score = 0;
}  

void Engine::read_input(Gamepad &gamepad) {
  _input.coord = gamepad.get_mapped_coord(); 
  _input.A_flag = gamepad.check_event(Gamepad::A_PRESSED);
} 

void Engine::process_y(Gamepad &gamepad) {
  // Sets the y coord by first checking if the skater should be falling.
  set_fall_flag();
  if (_fall_flag) {
    _skater.fall(_fall_flag, gamepad);
  } else {
    _skater.set_y_position( _input.A_flag, _jump_counter, _level_condition, 
                           gamepad);
  }
  _fall_flag = _skater.get_fall_flag();  // Update fall flag.
  _skater_y = _skater.get_y_position();
  _jump_counter = _skater.get_jump_counter();  // Update jump counter.
}

void Engine::set_fall_flag() {
  // Set the fall flag to true if the skater is not on one of the lower 
  // platforms.
  if (((_lower_line_1.x_end < _skater_x) 
      && (_skater_x < (_lower_line_2.x_start - 6)))  
      && _skater_y == 23) {
    _fall_flag = true; 
  } else if (((_lower_line_2.x_end < _skater_x) 
             && (_skater_x < (_lower_line_3.x_start - 6))) 
             && _skater_y == 23) {
    _fall_flag = true;
  } else if (((_lower_line_3.x_end < _skater_x) 
             && (_skater_x < (_lower_line_1.x_start - 6))) 
             && _skater_y == 23) {
    _fall_flag = true;
  }   
}
    
void Engine::process_x(int game_counter) {
  // Sets the x coord.
  _skater.set_x_position_and_sprite(_input.coord.x, 
    _moving_counter, 
    _skater_direction,
    _input.coord.y);
  _skater_x = _skater.get_x_position();
  _moving_counter = _skater.get_moving_counter();  // Update moving counter.
  _speed_divider = int(-0.05*_player_score + 4);
  if ((game_counter % _speed_divider == 0) && (_input.coord.x > -0.1)) {  
  // Move the skater along with platforms at rate determined by speed divider.
    _moving_counter--;
  }
}
    
void Engine::process_sprite() {
  // Update the sprite and direction.
  _skater_sprite = _skater.get_sprite_value();
  _skater_direction = _skater.get_direction();
}


void Engine::set_level_condition() {
  // If the skater is under or on top of any of the upper platforms, set
  // level condition to 1.
  if (((_upper_line_1.x_start - 6) <= _skater_x) 
      && (_skater_x <= _upper_line_1.x_end)) {
    _level_condition = 1; 
  } else if (((_upper_line_2.x_start - 6) <= _skater_x) 
             && (_skater_x <= _upper_line_2.x_end)) {
    _level_condition = 1;
  } else if (((_upper_line_3.x_start - 6) <= _skater_x) 
             && (_skater_x <= _upper_line_3.x_end)) {
    _level_condition = 1;
  } else {
    _level_condition = 0;
  }   
}
    
void Engine::generate_level(int game_counter) {
  generate_lower_lines();
  generate_upper_lines();
  _coin.generate_coin();
  generate_fire(game_counter);
}

void Engine::generate_lower_lines() {
  // Use a scaled random number to generate the length of the lower lines.
  _length_1 = (rand() %20) + 10;  // [1].   
  _lower_platforms.set_line_1(_length_1);
  _lower_line_1 = _lower_platforms.get_line_1(); 
  _length_2 = (rand() %20) + 10;  // [1].       
  _lower_platforms.set_line_2(_length_2);
  _lower_line_2 = _lower_platforms.get_line_2();
  _length_3 = (rand() %20) + 10;  // [1].      
  _lower_platforms.set_line_3(_length_3);
  _lower_line_3 = _lower_platforms.get_line_3();
}

void Engine::generate_upper_lines() {   
  // Set the length of the upper lines to be proportionally smaller to
  // the length of the lower lines.
  _upper_platforms.set_line_1(_length_1 / 2);
  _upper_line_1 = _upper_platforms.get_line_1();       
  _upper_platforms.set_line_2(_length_2 / 2);
  _upper_line_2 = _upper_platforms.get_line_2();  
  _upper_platforms.set_line_3(_length_3 / 2);
  _upper_line_3 = _upper_platforms.get_line_3();
}

void Engine::generate_fire(int game_counter) {
  // Generates the x and y coordinate of the fire. Y oscillates from 5 to 23.
  _fire.generate_fire(); // Generates X coord of fire.
  _fire_y = int(-0.0073*game_counter*game_counter + 0.73*game_counter + 5);  
  // Y is calculated from parabolic relation to game counter. 
}

void Engine::update_lcd(N5110 &lcd){
  lcd.drawSprite(_skater_x,_skater_y,17,10,
                (int *)_skater.get_sprite(_skater_sprite));
  lcd.drawSprite(_coin.get_coin_x(),_coin.get_coin_y(),5,5,
                 (int*)_coin.get_coin_sprite());
  lcd.drawSprite(_fire.get_fire_x(),_fire_y,5,8,(int*)_fire.get_fire_sprite()); 
  lcd.drawLine(_lower_line_2.x_start,_lower_line_2.y,_lower_line_2.x_end,
               _lower_line_2.y,FILL_BLACK);
  lcd.drawLine(_lower_line_1.x_start,_lower_line_1.y,_lower_line_1.x_end,
               _lower_line_1.y,FILL_BLACK);
  lcd.drawLine(_lower_line_3.x_start,_lower_line_3.y,_lower_line_3.x_end,
               _lower_line_3.y,FILL_BLACK);
  lcd.drawLine(_upper_line_2.x_start,_upper_line_2.y,_upper_line_2.x_end,
               _upper_line_2.y,FILL_BLACK);
  lcd.drawLine(_upper_line_1.x_start,_upper_line_1.y,_upper_line_1.x_end,
               _upper_line_1.y,FILL_BLACK);
  lcd.drawLine(_upper_line_3.x_start,_upper_line_3.y,_upper_line_3.x_end,
               _upper_line_3.y,FILL_BLACK);
  sprintf(buffer,"%2d",_player_score);
  lcd.printString(buffer,0,0);
}

bool Engine::get_start_platform_flag() {
  if (_input.A_flag) _start_platform_flag = false;  // Means starting platform 
  // will vanish after first jump of the game.
  return _start_platform_flag;
}

void Engine::check_coin_collision(Gamepad &gamepad) {
  if (_skater_x == _coin.get_coin_x() 
      && (_skater_y == _coin.get_coin_y() - 10)) {  // Small adjustment for Y 
  // coord compensates for skater sprite size.
    _coin_collision_flag = true;
    _player_score++;
    _coin.set_coin((rand() % 100),(abs(rand() % 100 - 20)));  // Place coin 
    // on a constrained random position, [1].
    gamepad.tone(1500, 0.05);  // Make noise on buzzer.
    wait(0.05);
    gamepad.tone(3000, 0.05);   
  }
}

void Engine::check_fire_collision(Gamepad &gamepad) {
  if (_input.coord.y > -0.1 
      && _skater_x == _fire.get_fire_x() 
      && _skater_y > _fire_y - 10 
      && _skater_y < _fire_y + 10) {  // If skater is not ducking. A range of Y 
  // coords to make collision more frequent.
    _skater.set_reset_flag(true);
    gamepad.tone(400, 0.25); // Make noise on buzzer.
    wait(0.05);
    gamepad.tone(200, 0.25);
  } else if ( _skater_x < -10 || _skater_x > 84 ) { // If skater goes off the 
  // screen.
    _skater.set_reset_flag(true);
    gamepad.tone(200, 0.5);
  }
}

int Engine::get_player_score() {
  return _player_score;
}