Im reading the book "Beginning Game Programming" second edition by Jonathan s. Harbour,
and in chapter 5 my program crashes at d3d->CreateDevice. here is my source code:


//Beginning game programming
//Chapter 5
//d3d_windowed program

#include <d3d9.h>
#include <time.h>

#define APPTITLE "Direct3d_Windowed"

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

LPDIRECT3D9 d3d = NULL;
LPDIRECT3DDEVICE9 d3ddev = NULL;

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);
}

ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wc;
wc.cbSize = sizeof(WNDCLASSEX);
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;

return RegisterClassEx(&wc);
}

int WINAPI WinMain(HINSTANCE hInstance,
HINSTANCE hPreviousInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
MSG msg;

MyRegisterClass(hInstance);

HWND hWnd;

hWnd = CreateWindow(
APPTITLE,
APPTITLE,
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
500,
400,
NULL,
NULL,
hInstance,
NULL);

if (!hWnd)
return FALSE;

ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);

if (!Game_Init(hWnd))
return 0;

int done = 0;

while (!done)
{
if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))
{
if (msg.message == WM_QUIT)
{
MessageBox(hWnd,"Recieved WM_QUIT message","WinMain",MB_OK);
done = 1;
}

TranslateMessage(&msg);
DispatchMessage(&msg);
}

else
Game_Run(hWnd);
}
return msg.wParam;
}

int Game_Init(HWND hWnd)
{
MessageBox(hWnd,"Game Is About To Run", "Game_Init",MB_OK);

d3d = Direct3DCreate9(D3D_SDK_VERSION);

if (d3d = NULL)
{
MessageBox(hWnd,"Error Initializing Direct3d","Error",MB_OK);
return 0;
}

D3DPRESENT_PARAMETERS d3dpp;
ZeroMemory(&d3dpp,sizeof(d3dpp));
d3dpp.Windowed = TRUE;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;

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;
}

srand(time(NULL));

return 1;
}

void Game_Run(HWND hWnd)
{
if (d3ddev == NULL)
return;

d3ddev->Clear(0,NULL,D3DCLEAR_TARGET,D3DCOLOR_XRGB(0,255,255),1.0f,0);

if (d3ddev->BeginScene())
{
d3ddev->EndScene();
}

d3ddev->Present(NULL,NULL,NULL,NULL);
}

void Game_End(HWND hWnd)
{
MessageBox(hWnd,"Program is about to end","Game_End",MB_OK);

if (d3ddev != NULL)
d3ddev->Release();

if (d3d != NULL)
d3d->Release();
}


it seems that the crush has something to do with the pointers of d3d and d3ddev although i might be mistaken.

All help will be greatly appreciated.

Your problem is this line:

if (d3d = NULL)

...

it's assigning your d3d pointer to NULL, instead of comparing... what you want is :

if (d3d == NULL)

...

Wow,
do i feel silly.

Thank you so much, i dont know how i could miss that.