#include "Global.h"

DISPLAYSETTINGS	Display;																		//Contains resolution, color depth, z buffer depth
PADDLE			PaddleLeft;																		//Create a paddle
PADDLE			PaddleRight;																	//Create a paddle
BALL			Ball;																			//Create a ball
BOOL			key[256];																		//Allows for smooth keyboard movement

extern FMUSIC_MODULE *Song0;
int currentCamera=0;																			//Keeps track of the current camera position

HINSTANCE hInstance;

BOOL CALLBACK SetupDialogProc(HWND hDlg,UINT message,WPARAM wParam,LPARAM lParam){
	GetFocus();
	switch(message){
	case WM_INITDIALOG:
		break;
	case WM_COMMAND:
		switch(LOWORD(wParam)){
		case IDC_PLAY:
			EndDialog(hDlg,0);
			break;
		default:
			return FALSE;
		}
	}
	return TRUE;
}

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int iCmdShow){	//WinMain
	WNDCLASS	wc;
	HWND		hWnd;																			//Window handle
	MSG			msg;																			//Message datatype
	BOOL		Done=FALSE;																		//Boolean value. If Done==TRUE, then exit
	HDC			hDC;																			//Device context handle
	HGLRC		hRC;																			//Rendering context handle

	//REGISTER WINDOW CLASS
	wc.style			=	CS_OWNDC;															//Creates a private DC for the Window (DC is not shared across applications)
	wc.lpfnWndProc		=	WndProc;															//Handles messages
	wc.cbClsExtra		=	0;																	//No extra window data
	wc.cbWndExtra		=	0;																	//No extra window data
	wc.hInstance		=	hInstance;															//Set the instance
	wc.hIcon			=	LoadIcon(hInstance,"Pong3D");										//Load the Pong3D icon
	wc.hCursor			=	LoadCursor(NULL,IDC_ARROW);											//Load the mouse arrow pointer
	wc.hbrBackground	=	NULL;																//No background brush is required in OpenGL
	wc.lpszMenuName		=	NULL;
	wc.lpszClassName	=	"Pong3D";

	if(!RegisterClass(&wc)){																	//Attempt to register the class
		ErrorMsg("Fatal: Pong 3D was unable to register the window class. Aborting");			//If failed, display error message
		return 0;																				//Exit WinMain
	}

	DisplaySettings(&Display,1024,768,16,16);													//Set the display settings

	if(!(hWnd=CreateWindowEx(WS_EX_APPWINDOW,"Pong3D","Pong3D",WS_POPUP|WS_CLIPSIBLINGS,		//Attempt to create the window
		0,0,Display.width,Display.height,NULL,NULL,hInstance,NULL))){
		ErrorMsg("Fatal: Pong3D was unable to create the window. Aborting");					//If window creation fails, display error message
		return 0;																				//Exit WinMain
	}

	DEVMODE dmScreenSettings;																	//Device Mode
	memset(&dmScreenSettings,0,sizeof(dmScreenSettings));										//Makes Sure Memory's Cleared
	dmScreenSettings.dmSize			= sizeof(dmScreenSettings);									//Size Of The Devmode Structure
	dmScreenSettings.dmPelsWidth	= Display.width;											//Selected Screen Width
	dmScreenSettings.dmPelsHeight	= Display.height;											//Selected Screen Height
	dmScreenSettings.dmBitsPerPel	= Display.colorBits;										//Selected Bits Per Pixel
	dmScreenSettings.dmFields		= DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
	
	if(ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL){		//Attempt to enter full screen device mode
		ErrorMsg("Your graphics card does not support full screen device mode. Aborting");		//if failed, display error message
		return 0;																				//Exit WinMain
	}

	if(!EnableOpenGL(hWnd,&hDC,&hRC)){															//Attempt to enable OpenGL for the window
		ErrorMsg("Fatal: OpenGL was unable to initialize. Aborting");							//If failed, display an error message
		return 0;																				//exit WinMain
	}
	LoadSounds();																				//Load sfx and music into memory
	PlayMusic(Song0);																			//Stream the music
	SetupRC();																					//Set up the rendering context
	ResetGame(&PaddleLeft,&PaddleRight,&Ball);													//Start a new game

	while(!Done){																				//Program main loop
		if(PeekMessage(&msg,NULL,0,0,PM_REMOVE)){												//Check for quit message
			if(msg.message==WM_QUIT) Done = TRUE;												//If WM_QUIT then break the main loop
			else{																				//If program hasnt recieved WM_QUIT...
				TranslateMessage(&msg);															//Translates keystrokes that may be specific to this application
				DispatchMessage(&msg);															//Pass message to Windows, WndProc, etc
			}
		}
		else{
////////////////OPENGL CODING STARTS HERE////////////////
			glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);									//Clear screen with current color			
			MoveBall(&Ball);																	//Move the ball
			Collision(&PaddleLeft,&PaddleRight,&Ball);											//Check for collisions
			DrawPaddle(&PaddleLeft,-PLAYFIELD_W);												//Draw the left paddle to the screen
			DrawPaddle(&PaddleRight,PLAYFIELD_W);												//Draw the right paddle to the screen
			DrawBall(&Ball);																	//Draw the ball to the screen
			DrawBackBoard();																	//Draw the backboard
			ChooseCamera(currentCamera);														//Use the given camera
			SwapBuffers(hDC);																	//Swap virtual screen to physical screen
/////////////////OPENGL CODING ENDS HERE/////////////////
			ProcessKeys();																		//Process user input
		}
	}
	FreeSounds();																				//Free the sounds and music from memory
	ChangeDisplaySettings(NULL,0);																//Switch display settings back to desktop mode

	if(!DisableOpenGL(hWnd,hDC,hRC))															//Attempt to shutdown OpenGL
		ErrorMsg("An error occurred while attempting to disable OpenGL");						//Display an error message
	if(!DestroyWindow(hWnd))																	//Destroy the window explicitly
		ErrorMsg("Pong3D failed to destroy the window");										//Display an error message
	return msg.wParam;																			//Return back to the desktop
}

//Window Procedure (Process window messages)
LRESULT CALLBACK WndProc(HWND hWnd,UINT message,WPARAM wParam,LPARAM lParam){					//Processes messages
	switch(message){
		case WM_DESTROY:																		//Application is ready to close
			PostQuitMessage(0);																	//Terminates message loop in WinMain
			return 0;
		case WM_SYSCOMMAND:																		//Intercept System Commands
			if(wParam==SC_SCREENSAVE) return 0;													//Don't allow screensaver to start
		case WM_KEYDOWN:																		//If a key is being pressed			
			if(wParam==VK_RETURN){																//If user hits the enter key
				if(currentCamera>=MAX_CAMERAS-1) currentCamera=-1;								//If camera number exceeds MAX_CAMERAS set camera number to 0
				currentCamera++;																//Change the camera view
			}
			if(wParam==VK_F1) DialogBox(hInstance,"SetupDialog",hWnd,(DLGPROC)SetupDialogProc);
			key[wParam] = TRUE;																	//Set the key to true if it has been pressed
			return 0;
		case WM_KEYUP:																			//If a key is released
			key[wParam] = FALSE;																//If the key is released, set it to false
			return 0;
	}
	return DefWindowProc(hWnd,message,wParam,lParam);											//If message wasn't processed, return it to Windows
}

//This function attempts to get the device and rendering contexts.  Returns TRUE on success, FALSE on fail
BOOL EnableOpenGL(HWND hWnd,HDC *hDC,HGLRC *hRC){												//Enables OpenGL
	PIXELFORMATDESCRIPTOR pfd;																	//Pixel Format Descriptor
	int format;																					//To hold pixel format
	*hDC=GetDC(hWnd);																			//Get the device context (DC)

	//SET THE PIXEL FORMAT FOR THE DEVICE CONTEXT
	memset(&pfd,0,sizeof(pfd));
	pfd.nSize			= sizeof(pfd);															//Size of the pfd
	pfd.nVersion		= 1;																	//Always equals 1
	pfd.dwFlags			= PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|PFD_DOUBLEBUFFER;				//Pixel format: is used to draw to window, needs to support OpenGL, has double buffering capabilities
	pfd.iPixelType		= PFD_TYPE_RGBA;														//Pixel type (Red Green Blue Alpha)
	pfd.cColorBits		= Display.colorBits;													//24 bit color buffer
	pfd.cDepthBits		= Display.depthBits;													//16 bit depth buffer

	format = ChoosePixelFormat(*hDC,&pfd);														//Choose correct pixel format
	SetPixelFormat(*hDC,format,&pfd);															//Set the pixel format
 
	*hRC=wglCreateContext(*hDC);																//Create rendering context
	if(!wglMakeCurrent(*hDC,*hRC)) return FALSE;												//Enable rendering context
	return TRUE;																				//Return true if deinitialization was successful
}

//This function attempts to release the device and rendering contexts.  Returns TRUE on success, FALSE on fail
BOOL DisableOpenGL(HWND hWnd,HDC hDC,HGLRC hRC){
	if(!wglMakeCurrent(NULL,NULL)) return FALSE;												//Attempt to release the rendering context
	if(!wglDeleteContext(hRC)) return FALSE;													//Attempt to delete the rendering context
	if(!ReleaseDC(hWnd,hDC)) return FALSE;														//Attempt to release the device context
	return TRUE;																				//Return true if deinitialization was successful
}

//This function initializes the members of the DISPLAYSETTINGS structure with the given arguments
VOID DisplaySettings(struct DISPLAYSETTINGS *displaySettings, int w,int h,int color,int depth){
	displaySettings->colorBits=color;															//Set the color depth
	displaySettings->depthBits=depth;															//Set the depth bits
	displaySettings->height=h;																	//Set the screen height resolution
	displaySettings->width=w;																	//Set the screen width resolution
}

//Sets up our rendering context
VOID SetupRC(void){
	glEnable(GL_DEPTH_TEST);																	//Enable depth testing (Don't show hidden faces)
	glEnable(GL_CULL_FACE);																		//Don't draw back faces
	glFrontFace(GL_CCW);																		//Shapes have a counter-clockwise winding
	glEnable(GL_LIGHTING);
	glEnable(GL_COLOR_MATERIAL);
	glColorMaterial(GL_FRONT,GL_AMBIENT_AND_DIFFUSE);
	glClearColor(0.0f,0.0f,0.0f,1.0f);															//Set the color
	glViewport(0,0,Display.width,Display.height);												//Set the viewport
	glMatrixMode(GL_PROJECTION);																//Switch to perspective mode
	glLoadIdentity();																			//Reset the perspective matrix
	gluPerspective(45.0f,Display.width/Display.height,1.0,400.0);								//Set to perspective mode. (Objects converge in distance)
	glMatrixMode(GL_MODELVIEW);																	//Switch to model matrix
	glLoadIdentity();																			//Reset the model matrix
	SetupLights();
}

VOID ErrorMsg(char *Message){																	//Display an error message with the given string
	MessageBeep(0);																				//Make a beep
	MessageBox( GetFocus(),Message,"Pong3D - An error has occurred",MB_ICONASTERISK|MB_OK );	//Display the message
}