// Beginning Game Programming
// Chapter 6
// Load_Bitmap program

//header files to include
#pragma comment(lib, "libd3d9.a")
#include <d3d9.h>
#include <d3dx9.h>
#include <time.h>




//application title
#define APPTITLE "Create_Surface"

//macros to read the keyboard asynchronously
#define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEY_UP(vk_code)((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)

//screen resolution
#define SCREEN_WIDTH 1440
#define SCREEN_HEIGHT 900

//forward declarations
LRESULT WINAPI WinProc(HWND,UINT,WPARAM,LPARAM);
ATOM MyRegisterClass(HINSTANCE);
int Game_Init(HWND);
void Game_Run(HWND);
void Game_End(HWND);

//Direct3D objects
LPDIRECT3D9 d3d = NULL; 
LPDIRECT3DDEVICE9 d3ddev = NULL; 

LPDIRECT3DSURFACE9 backbuffer = NULL;
LPDIRECT3DSURFACE9 surface = NULL;


//window event callback function
LRESULT WINAPI WinProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
    switch( msg )
    {
        case WM_DESTROY:
            Game_End(hWnd);
            PostQuitMessage(0);
            return 0;
    }

    return DefWindowProc( hWnd, msg, wParam, lParam );
}


//helper function to set up the window properties
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    //create the window class structure
    WNDCLASSEX wc;
    wc.cbSize = sizeof(WNDCLASSEX); 

    //fill the struct with info
    wc.style         = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc   = (WNDPROC)WinProc;
    wc.cbClsExtra	 = 0;
    wc.cbWndExtra	 = 0;
    wc.hInstance     = hInstance;
    wc.hIcon         = NULL;
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = APPTITLE;
    wc.hIconSm       = NULL;

    //set up the window with the class info
    return RegisterClassEx(&wc);
}


//entry point for a Windows program
int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR     lpCmdLine,
                   int       nCmdShow)
{
    // declare variables
	MSG msg;

	// register the class
	MyRegisterClass(hInstance);

    // initialize application 
    //note--got rid of initinstance
    HWND hWnd;

    //create a new window
    hWnd = CreateWindow(
       APPTITLE,              //window class
       APPTITLE,              //title bar
       WS_EX_TOPMOST | WS_VISIBLE | WS_POPUP,   //window style
       CW_USEDEFAULT,         //x position of window
       CW_USEDEFAULT,         //y position of window
       SCREEN_WIDTH,          //width of the window
       SCREEN_HEIGHT,         //height of the window
       NULL,                  //parent window
       NULL,                  //menu
       hInstance,             //application instance
       NULL);                 //window parameters

    //was there an error creating the window?
    if (!hWnd)
      return FALSE;

    //display the window
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);
	
	//initialize the game
    if (!Game_Init(hWnd))
        return 0;


    // main message loop
    int done = 0;
	while (!done)
    {
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) 
	    {
            //look for quit message
            if (msg.message == WM_QUIT)
                done = 1;

            //decode and pass messages on to WndProc
		    TranslateMessage(&msg);
		    DispatchMessage(&msg);
	    }
        else
            //process game loop (else prevents running after window is closed)
            Game_Run(hWnd);
    }

	return msg.wParam;
}


int Game_Init(HWND hwnd)
{
    HRESULT result;

    //initialize Direct3D
    d3d = Direct3DCreate9(D3D_SDK_VERSION);
    if (d3d == NULL)
    {
        MessageBox(hwnd, "Error initializing Direct3D", "Error", MB_OK);
        return 0;
    }

    //set Direct3D presentation parameters
    D3DPRESENT_PARAMETERS d3dpp; 
    ZeroMemory(&d3dpp, sizeof(d3dpp));

    d3dpp.Windowed = FALSE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;
    d3dpp.BackBufferCount = 1;
    d3dpp.BackBufferWidth = SCREEN_WIDTH;
    d3dpp.BackBufferHeight = SCREEN_HEIGHT;
    d3dpp.hDeviceWindow = hwnd;

    //create Direct3D device
    d3d->CreateDevice(
        D3DADAPTER_DEFAULT, 
        D3DDEVTYPE_HAL, 
        hwnd,
        D3DCREATE_SOFTWARE_VERTEXPROCESSING,
        &d3dpp, 
        &d3ddev);

    if (d3ddev == NULL)
    {
        MessageBox(hwnd, "Error creating Direct3D device", "Error", MB_OK);
        return 0;
    }

	//set random number seed
	srand(time(NULL));

    //clear the backbuffer to black
    d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,0), 1.0f, 0);
    
    //create surface
    result = d3ddev->CreateOffscreenPlainSurface(
        640,                //width of the surface
        480,                //height of the surface
        D3DFMT_X8R8G8B8,    //surface format
        D3DPOOL_DEFAULT,    //memory pool to use
        &surface,           //pointer to the surface
        NULL);              //reserved (always NULL)

    if (result != D3D_OK)
        return 1;

    //load surface from file into newly created surface
    result = D3DXLoadSurfaceFromFile(
        surface,            //destination surface
        NULL,               //destination palette
        NULL,               //destination rectangle
        "legotron.bmp",     //source filename
        NULL,               //source rectangle
        D3DX_DEFAULT,       //controls how image is filtered
        0,                  //for transparency (0 for none)
        NULL);              //source image info (usually NULL)

    //make sure file was loaded okay
    if (result != D3D_OK)
        return 1;

    //return okay
    return 1;
}

void Game_Run(HWND hwnd)
{
    //make sure the Direct3D device is valid
    if (d3ddev == NULL)
        return;

    //start rendering
    if (d3ddev->BeginScene())
    {
        //create pointer to the back buffer
        d3ddev->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &backbuffer);

        //draw surface to the backbuffer
        d3ddev->StretchRect(surface, NULL, backbuffer, NULL, D3DTEXF_NONE);

       
        //stop rendering
        d3ddev->EndScene();
    }

    //display the back buffer on the screen
    d3ddev->Present(NULL, NULL, NULL, NULL);

    //check for escape key (to exit program)
    if (KEY_DOWN(VK_ESCAPE))
        PostMessage(hwnd, WM_DESTROY, 0, 0);

}

void Game_End(HWND hwnd)
{
    //free the surface
    surface->Release();

    //release the Direct3D device
    if (d3ddev != NULL) 
        d3ddev->Release();

    //release the Direct3D object
    if (d3d != NULL)
        d3d->Release();
}