Direct3D的初始化

对于我这种今天才刚开学学习DX的初学者来说，初始化Direct3D真是件让人头疼的事。不过好歹对照龙书弄出来了。。

初始化Direct3D的步骤：

1、获取IDirect3D9的指针

2、查检设备性能。判断主显卡是否支持硬件顶点运算

3、初始化D3DPRESENT_PARAMETERS结构体的一个实例

4、创建IDirect3DDevice9对像 （它代表了我们用来显示3D图形的物理设备对像）

IDirect3DDevice9 *pDevice = NULL;
// Step 1:得到指向IDirect3D9的指针 
	IDirect3D9* d3d9 = 0;
    d3d9 = Direct3DCreate9(D3D_SDK_VERSION);

    if( !d3d9 )
	{
		::MessageBox(0, "Direct3DCreate9() - FAILED", 0, 0);
		return false;
	}

	// Step 2:检查硬件性能

	D3DCAPS9 caps;
	d3d9->GetDeviceCaps(D3DADAPTER_DEFAULT, deviceType, &caps);

	int vp = 0;
	if( caps.DevCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT )
		vp = D3DCREATE_HARDWARE_VERTEXPROCESSING;
	else
		vp = D3DCREATE_SOFTWARE_VERTEXPROCESSING;

	// Step 3:填充结构体 
	D3DPRESENT_PARAMETERS d3dpp;
	d3dpp.BackBufferWidth            = width;
	d3dpp.BackBufferHeight           = height;
	d3dpp.BackBufferFormat           = D3DFMT_A8R8G8B8;
	d3dpp.BackBufferCount            = 1;
	d3dpp.MultiSampleType            = D3DMULTISAMPLE_NONE;
	d3dpp.MultiSampleQuality         = 0;
	d3dpp.SwapEffect                 = D3DSWAPEFFECT_DISCARD; 
	d3dpp.hDeviceWindow              = hwnd;
	d3dpp.Windowed                   = windowed;
	d3dpp.EnableAutoDepthStencil     = true; 
	d3dpp.AutoDepthStencilFormat     = D3DFMT_D24S8;
	d3dpp.Flags                      = 0;
	d3dpp.FullScreen_RefreshRateInHz = D3DPRESENT_RATE_DEFAULT;
	d3dpp.PresentationInterval       = D3DPRESENT_INTERVAL_IMMEDIATE;

	// Step 4:创建设备对象
	hr = d3d9->CreateDevice(
		D3DADAPTER_DEFAULT, // primary adapter
		deviceType,         // device type
		hwnd,               // window associated with device
		vp,                 // vertex processing
	    &d3dpp,             // present parameters
	    device);            // return created device
d3d9->Release();