//---------------------------------------------------------------------------
/*
Book:           AI for Game Developers
Authors:        David M. Bourg & Glenn Seemann
Example:        Pattern movement in continuous environments, Chapter 3
*/
//---------------------------------------------------------------------------
// Windows Header Files:
#include <windows.h>
#include <windef.h>
#include <commctrl.h>
#include <commdlg.h>
#include <wingdi.h> 

// C RunTime Header Files:
#include <stdlib.h>
#include <malloc.h>
#include <memory.h>
#include <stdio.h>
#include <math.h>

// Local Header Files:
#include "resource.h"
#include "winmain.h"


// Defines:
#define	APPNAME	"AI Ch2 Demo"

// Forward declarations for non-window related functions
void	DrawLineToDC(HDC hdc, int h1, int v1, int h2, int v2, int thk, COLORREF clr);
void	DrawRectangleToDC(HDC hdc, RECT *r, int thk, COLORREF borderCLR, COLORREF fillCLR);
void	DrawEllipseToDC(HDC hdc, RECT *r, int thk, COLORREF clr);
void	DrawStringToDC(HDC hdc, int x, int y, LPCSTR lpszString, int size, int ptsz);
void	CreateBackBuffer(void);
void	DeleteBackBuffer(void);



// Forward declarations for window related functions
LRESULT CALLBACK DemoDlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK DefaultWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);


BOOL InitApplication(HINSTANCE);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);



// Window related global variables
HINSTANCE		hinst; 
HWND			hMainWindow;
RECT			MainWindowRect;
HDC				BackBufferDC;
HBITMAP			hBackBuffer;
LPBITMAPINFO	lpBackBufferBitmapInfo;
bool			Initialized = false;
int				nShowCmd;

/*HINSTANCE	hInst; // current instance
int			nShowCmd; // current show command	
char		szAppName[] = APPNAME; // The name of this application
char		szTitle[]   = APPNAME; // The title bar text
HWND		hTheMainWindow;
*/

// globals

bool	ShowTrails;
bool	ShowVectors;
bool	BasicChase;
bool	BasicEvade;
bool	InterceptChase;
bool	PotentialChase;
bool	Patrol;
bool	ZigZag;


// Forward declarations for non-window related functions
void	InitializeVariables(void);
void	DrawTopView(HDC hdc, RECT *r);
void	DrawLine(HDC hdc, int h1, int v1, int h2, int v2, int thk, COLORREF clr);
void	DrawRectangle(HDC hdc, RECT *r, int thk, COLORREF clr);
void	DrawString(HDC hdc, int x, int y, LPCSTR lpszString, int size, int ptsz);

extern	void UpdateSimulation(void);
extern	bool Initialize(void);

//----------------------------------------------------------------------------------------------------//
// This is the applications "main" function. Note that I'm not using a message loop here
// since there is no main window. All I do is display a dialog box immediately upon startup
// and let the dialog handler take care of the messages.
//----------------------------------------------------------------------------------------------------//
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
//----------------------------------------------------------------------------------------------------//
{	

	MSG msg;
	HANDLE hAccelTable;		

	if (!hPrevInstance) {
		// Perform instance initialization:
		if (!InitApplication(hInstance)) {
			return (FALSE);
		}
	}

	// Perform application initialization:	
	if (!InitInstance(hInstance, nCmdShow)) {
		return (FALSE);
	}

	hAccelTable = LoadAccelerators (hInstance, APPNAME);

	// Main message loop:
	while (1) {		

		while(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
			if (msg.message == WM_QUIT) {
				return msg.wParam;
			}
			TranslateMessage(&msg);
			DispatchMessage(&msg);			
		}
		
		if(Initialized)
			UpdateSimulation();

	}

	return (msg.wParam);

	lpCmdLine; // This will prevent 'unused formal parameter' warnings



}


BOOL InitApplication(HINSTANCE hInstance)
{
    WNDCLASS  wc;
    HWND      hwnd;

    hwnd = FindWindow (APPNAME, NULL);
    if (hwnd) {
        if (IsIconic(hwnd)) {
            ShowWindow(hwnd, SW_RESTORE);
        }
        SetForegroundWindow (hwnd);

        return FALSE;
        }

        wc.style         = CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS;
        wc.lpfnWndProc   = (WNDPROC)WndProc;
        wc.cbClsExtra    = 0;
        wc.cbWndExtra    = 0;
        wc.hInstance     = hInstance;
        wc.hIcon         = NULL;//LoadIcon (hInstance, MAKEINTRESOURCE(IDI_MAINICON));
        wc.hCursor       = LoadCursor(NULL, IDC_ARROW);//NULL
        wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);//(HBRUSH)(COLOR_WINDOW+1);

		wc.lpszMenuName = MAKEINTRESOURCE(IDR_MAINMENU);
		
		wc.lpszClassName = APPNAME;
        
		return RegisterClass(&wc);
}


BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{			
	hinst = hInstance;
	nShowCmd = nCmdShow;	

	MainWindowRect.left = 0;
	MainWindowRect.top = 0;
	MainWindowRect.right = _WINWIDTH;
	MainWindowRect.bottom = _WINHEIGHT;
 
	hMainWindow = CreateWindow(	APPNAME, 
								APPNAME,
								WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN | WS_CLIPSIBLINGS,
								0, 0, _WINWIDTH, _WINHEIGHT,
								NULL, NULL, hinst, NULL);
			
	// create back buffer
	CreateBackBuffer();

	ShowWindow(hMainWindow, nCmdShow);
    UpdateWindow(hMainWindow);

	Initialized = Initialize();

	return (TRUE);
}


LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	
	int			wmId, wmEvent;   		
	BOOL		validmenu = FALSE;	
	int			selection =0;
	PAINTSTRUCT			ps;
	HDC			pDC;
	WPARAM		key;
	int			w, h;
	UINT		state;
	
	switch (message) {

		case WM_CREATE:
			ShowTrails = true;
			ShowVectors = false;
			BasicChase = false;
			BasicEvade = false;
			InterceptChase = false;
			PotentialChase = false;
			Patrol = false;
			ZigZag = true;
			break;

		case WM_ACTIVATE:
			state = ShowTrails ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_SHOWTRAILS, state);
			
			state = ShowVectors ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_SHOWVECTORS, state);
			
			state = BasicChase ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_BASICCHASE, state);

			state = BasicEvade ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_BASICEVADE, state);

			state = InterceptChase ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_INTERCEPT, state);

			state = PotentialChase ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_POTENTIALCHASE, state);

			state = Patrol ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_SQUAREPATROL, state);

			state = ZigZag ? MF_CHECKED:MF_UNCHECKED;
			CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_ZIGZAG, state);

			break;

		case WM_COMMAND:
			wmId    = LOWORD(wParam); 
			wmEvent = HIWORD(wParam); 
			
			switch(wmId) {

				case ID_CLOSEMENU:
					DeleteBackBuffer();
					PostQuitMessage(0);
					break;

				case ID_OPTIONS_SHOWTRAILS:
					ShowTrails = !ShowTrails;
					state = ShowTrails ? MF_CHECKED:MF_UNCHECKED;
					CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_SHOWTRAILS, state);
					break;

				case ID_OPTIONS_SHOWVECTORS:
					ShowVectors = !ShowVectors;
					state = ShowVectors ? MF_CHECKED:MF_UNCHECKED;
					CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_SHOWVECTORS, state);					
					break;

				case ID_OPTIONS_BASICCHASE:
					BasicChase = !BasicChase;
					state = BasicChase ? MF_CHECKED:MF_UNCHECKED;
					CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_BASICCHASE, state);

					if(BasicEvade)
					{
						BasicEvade = false;
						CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_BASICEVADE, MF_UNCHECKED);
					}

					if(InterceptChase)
					{
						InterceptChase = false;
						CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_INTERCEPT, MF_UNCHECKED);
					}

					break;

				case ID_OPTIONS_BASICEVADE:
					BasicEvade = !BasicEvade;
					state = BasicEvade ? MF_CHECKED:MF_UNCHECKED;
					CheckMenuItem(GetMenu(hMainWindow), ID_OPTIONS_BASICEVADE, state);
					
					if(BasicChase)