PlayState.cpp

#include "PlayState.h"
#include <iostream>
#include "TextureManager.h"
#include "Game.h"
#include "Player.h"
#include "Enemy.h"
#include "InputHandler.h"
#include "PauseState.h"
#include "GameOverState.h"

const std::string PlayState::s_playID = "PLAY";

void PlayState::update()
{	
	//listen for ESC key to pause the game
	if (TheInputHandler::Instance()->isKeyDown(SDL_SCANCODE_ESCAPE))
	{
		TheGame::Instance()->getStateMachine()->pushState(new PauseState());
	}

	for (int i = 0; i < (int)m_gameObjects.size(); ++i)
	{
		m_gameObjects[i]->update();
	}

	if (checkCollision(dynamic_cast<SDLGameObject*>(m_gameObjects[0]), dynamic_cast<SDLGameObject*>(m_gameObjects[1])))
	{
		TheGame::Instance()->getStateMachine()->pushState(new GameOverState());
	}
}

void PlayState::render()
{
	for (int i = 0; i < (int)m_gameObjects.size(); ++i)
	{
		m_gameObjects[i]->draw();
	}
}

bool PlayState::onEnter()
{
	if (!TheTextureManager::Instance()->load("assets/helicopter.png", "helicopter", TheGame::Instance()->getRenderer()))
	{
		return false;
	}

	if (!TheTextureManager::Instance()->load("assets/helicopter2.png", "helicopter2", TheGame::Instance()->getRenderer()))
	{
		return false;
	}

	GameObject* player = new Player(new LoaderParams(500, 100, 128, 55, 5, "helicopter"));
	GameObject* enemy = new Enemy(new LoaderParams(100, 100, 128, 55, 5, "helicopter2"));

	m_gameObjects.push_back(player);
	m_gameObjects.push_back(enemy);

	std::cout << "entering PlayState\n";
	return true;
}

bool PlayState::onExit()
{	
	for (int i = 0; i < (int)m_gameObjects.size(); ++i)
	{
		m_gameObjects[i]->clean();
	}
	m_gameObjects.clear();
	TheTextureManager::Instance()->clearFromTextureMap("helicopter");

	std::cout << "exiting PlayState\n";
	return true;
}

//collision detection, will trigger the GameOverState
bool PlayState::checkCollision(SDLGameObject* p1, SDLGameObject* p2)
{
	float leftA, leftB;
	float rightA, rightB;
	float topA, topB;
	float bottomA, bottomB;

	leftA = p1->getPosition().getX();
	rightA = p1->getPosition().getX() + p1->getWidth();  
	topA = p1->getPosition().getY();  
	bottomA = p1->getPosition().getY() + p1->getHeight();
	
	//Calculate the sides of rect B  
	leftB = p2->getPosition().getX();  
	rightB = p2->getPosition().getX() + p2->getWidth();  
	topB = p2->getPosition().getY();  
	bottomB = p2->getPosition().getY() + p2->getHeight();
	
	//If any of the sides from A are outside of B  
	if (bottomA <= topB) { return false; }
	if (topA >= bottomB) { return false; }
	if (rightA <= leftB) { return false; }
	if (leftA >= rightB) { return false; }
	
	return true;
}