game.cpp

// Module:			Gameplay Programming
// Assignment 1:	Pixl

// Programming 2D Games
// Copyright (c) 2011 by: 
// Charles Kelly
// Chapter 6 game.cpp v1.0

#include "spacewar.h"

// The primary class should inherit from Game class

//=============================================================================
// Constructor
//=============================================================================
Game::Game()
{
	input = new Input();        // initialize keyboard input immediately
	// additional initialization is handled in later call to input->initialize()
	paused = false;             // game is not paused
	graphics = NULL;
	initialized = false;
}

//=============================================================================
// Destructor
//=============================================================================
Game::~Game()
{
	deleteAll();                // free all reserved memory
	ShowCursor(true);           // show cursor
}

//=============================================================================
// Window message handler
//=============================================================================
LRESULT Game::messageHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
	if (initialized)     // do not process messages if not initialized
	{
		switch (msg)
		{
		case WM_DESTROY:
		PostQuitMessage(0);        //tell Windows to kill this program
		return 0;
		case WM_KEYDOWN: case WM_SYSKEYDOWN:    // key down
		input->keyDown(wParam);
		return 0;
		case WM_KEYUP: case WM_SYSKEYUP:        // key up
		input->keyUp(wParam);
		return 0;
		case WM_CHAR:                           // character entered
		input->keyIn(wParam);
		return 0;
		case WM_MOUSEMOVE:                      // mouse moved
		input->mouseIn(lParam);
		return 0;
		case WM_INPUT:                          // raw mouse data in
		input->mouseRawIn(lParam);
		return 0;
		case WM_LBUTTONDOWN:                    // left mouse button down
		input->setMouseLButton(true);
		input->mouseIn(lParam);             // mouse position
		return 0;
		case WM_LBUTTONUP:                      // left mouse button up
		input->setMouseLButton(false);
		input->mouseIn(lParam);             // mouse position
		return 0;
		case WM_MBUTTONDOWN:                    // middle mouse button down
		input->setMouseMButton(true);
		input->mouseIn(lParam);             // mouse position
		return 0;
		case WM_MBUTTONUP:                      // middle mouse button up
		input->setMouseMButton(false);
		input->mouseIn(lParam);             // mouse position
		return 0;
		case WM_RBUTTONDOWN:                    // right mouse button down
		input->setMouseRButton(true);
		input->mouseIn(lParam);             // mouse position
		return 0;
		case WM_RBUTTONUP:                      // right mouse button up
		input->setMouseRButton(false);
		input->mouseIn(lParam);             // mouse position
		return 0;
		case WM_XBUTTONDOWN: case WM_XBUTTONUP: // mouse X button down/up
		input->setMouseXButton(wParam);
		input->mouseIn(lParam);             // mouse position
		return 0;
		case WM_DEVICECHANGE:                   // check for controller insert
		input->checkControllers();
		return 0;
		}
	}
	return DefWindowProc(hwnd, msg, wParam, lParam);    // let Windows handle it
}

//=============================================================================
// Initializes the game
// throws GameError on error
//=============================================================================
void Game::initialize(HWND hw)
{
	hwnd = hw;                                  // save window handle

	// initialize graphics
	graphics = new Graphics();
	// throws GameError
	graphics->initialize(hwnd, GAME_WIDTH, GAME_HEIGHT, FULLSCREEN);

	// initialize input, do not capture mouse
	input->initialize(hwnd, false);             // throws GameError

	// attempt to set up high resolution timer
	if (QueryPerformanceFrequency(&timerFreq) == false)
		throw(GameError(gameErrorNS::FATAL_ERROR, "Error initializing high resolution timer"));

	QueryPerformanceCounter(&timeStart);        // get starting time

	// Init sound system
	audio = new Audio();
	// If sound files defined
	if (*WAVE_BANK != '\0' && *SOUND_BANK != '\0') {
		if (FAILED(hr = audio->initialise())) {
			if (hr == HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND))
				throw(GameError(gameErrorNS::FATAL_ERROR,
				"Failed to initialize sound system" \
				"because media file not found."));
			else
				throw(GameError(gameErrorNS::FATAL_ERROR,
				"Failed to initialize sound system."));
		}
	}

	initialized = true;
}

//=============================================================================
// Render game items
//=============================================================================
void Game::renderGame()
{
	//start rendering
	if (SUCCEEDED(graphics->beginScene()))
	{
		render();           // call render() in derived object

		//stop rendering
		graphics->endScene();
	}
	handleLostGraphicsDevice();

	//display the back buffer on the screen
	graphics->showBackbuffer();
}

//=============================================================================
// Handle lost graphics device
//=============================================================================
void Game::handleLostGraphicsDevice()
{
	// test for and handle lost device
	hr = graphics->getDeviceState();
	if (FAILED(hr))                  // if graphics device is not in a valid state
	{
		// if the device is lost and not available for reset
		if (hr == D3DERR_DEVICELOST)
		{
			Sleep(100);             // yield cpu time (100 mili-seconds)
			return;
		}
		// the device was lost but is now available for reset
		else if (hr == D3DERR_DEVICENOTRESET)
		{
			releaseAll();
			hr = graphics->reset(); // attempt to reset graphics device
			if (FAILED(hr))          // if reset failed
				return;
			resetAll();
		}
		else
			return;                 // other device error
	}
}

//=============================================================================
// Call repeatedly by the main message loop in WinMain
//=============================================================================
void Game::run(HWND hwnd) {
	if (graphics == NULL)            // if graphics not initialized
		return;

	// calculate elapsed time of last frame, save in deltaTime
	QueryPerformanceCounter(&timeEnd);
	deltaTime = (float)(timeEnd.QuadPart - timeStart.QuadPart) / (float)timerFreq.QuadPart;

	// Power saving code, requires winmm.lib
	// if not enough time has elapsed for desired frame rate
	if (deltaTime < MIN_FRAME_TIME)
	{
		sleepTime = (DWORD)((MIN_FRAME_TIME - deltaTime) * 1000);
		timeBeginPeriod(1);         // Request 1mS resolution for windows timer
		Sleep(sleepTime);           // release cpu for sleepTime
		timeEndPeriod(1);           // End 1mS timer resolution
		return;
	}

	if (deltaTime > MAX_FRAME_TIME) // if frame rate is very slow
		deltaTime = MAX_FRAME_TIME; // limit maximum deltaTime

	timeStart = timeEnd;

	update();                   // update all game items
	UpdateEntities();
	ai();                       // artificial intelligence
	collisions();               // handle collisions

	renderGame();                   // draw all game items
	input->readControllers();       // read state of controllers

	input->clear(inputNS::KEYS_PRESSED);
}

void Game::releaseAll() {
}

void Game::resetAll()
{}

//=============================================================================
// Delete all reserved memory
//=============================================================================
void Game::deleteAll() {
	releaseAll();               // call onLostDevice() for every graphics item
	SAFE_DELETE(graphics);
	SAFE_DELETE(input);
	initialized = false;
}