03. Initializing Direct3D 11

全局变量

IDXGISwapChain* SwapChain;
ID3D11Device* d3d11Device;
ID3D11DeviceContext* d3d11DevCon;
ID3D11RenderTargetView* renderTargetView;

float red = 0.0f;
float green = 0.0f;
float blue = 0.0f;
int colormodr = 1;
int colormodg = 1;
int colormodb = 1;

函数原型

bool InitializeDirect3d11App(HINSTANCE hInstance);
void ReleaseObjects();
bool InitScene();
void UpdateScene();
void DrawScene();

if(!InitializeDirect3d11App(hInstance))    //Initialize Direct3D
{
    MessageBox(0, L"Direct3D Initialization - Failed",
        L"Error", MB_OK);
    return 0;
}

if(!InitScene())    //Initialize our scene
{
    MessageBox(0, L"Scene Initialization - Failed",
        L"Error", MB_OK);
    return 0;
}

messageloop();

ReleaseObjects();    

Initializing Direct3D 11初始化dx11

bool InitializeDirect3dApp(HINSTANCE hInstance)
{
HRESULT hr;

//Describe our Buffer
DXGI_MODE_DESC bufferDesc;

ZeroMemory(&bufferDesc, sizeof(DXGI_MODE_DESC));

bufferDesc.Width = Width;
bufferDesc.Height = Height;
bufferDesc.RefreshRate.Numerator = 60;
bufferDesc.RefreshRate.Denominator = 1;
bufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
bufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
bufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;

//Describe our SwapChain
DXGI_SWAP_CHAIN_DESC swapChainDesc; 
    
ZeroMemory(&swapChainDesc, sizeof(DXGI_SWAP_CHAIN_DESC));

swapChainDesc.BufferDesc = bufferDesc;
swapChainDesc.SampleDesc.Count = 1;
swapChainDesc.SampleDesc.Quality = 0;
swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
swapChainDesc.BufferCount = 1;
swapChainDesc.OutputWindow = hwnd; 
swapChainDesc.Windowed = TRUE; 
swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;


//Create our SwapChain
hr = D3D11CreateDeviceAndSwapChain(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, NULL, NULL, NULL,
    D3D11_SDK_VERSION, &swapChainDesc, &SwapChain, &d3d11Device, NULL, &d3d11DevCon);

//Create our BackBuffer
ID3D11Texture2D* BackBuffer;
hr = SwapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ), (void**)&BackBuffer );

//Create our Render Target
hr = d3d11Device->CreateRenderTargetView( BackBuffer, NULL, &renderTargetView );
BackBuffer->Release();

//Set our Render Target
d3d11DevCon->OMSetRenderTargets( 1, &renderTargetView, NULL );

return true;
}

Describing the BackBuffer( DXGI_MODE_DESC )

typedef struct DXGI_MODE_DESC {
  UINT                     Width;//宽度
  UINT                     Height;//高度
  DXGI_RATIONAL            RefreshRate;//刷新率 设为60HZ
  DXGI_FORMAT              Format;//显示方式 rgba每个8bit 一共32bit
  DXGI_MODE_SCANLINE_ORDER ScanlineOrdering;//渲染方式 不指定 双缓冲无所谓
  DXGI_MODE_SCALING        Scaling;//缩放 不指定
} DXGI_MODE_DESC, *LPDXGI_MODE_DESC;

DXGI_MODE_DESC bufferDesc;

ZeroMemory(&bufferDesc, sizeof(DXGI_MODE_DESC));

bufferDesc.Width = Width;
bufferDesc.Height = Height;
bufferDesc.RefreshRate.Numerator = 60;
bufferDesc.RefreshRate.Denominator = 1;
bufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
bufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;//渲染方式不指定
bufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;//缩放不指定

Describing the SwapChain( DXGI_MODE_DESC )

typedef struct DXGI_SWAP_CHAIN_DESC {
  DXGI_MODE_DESC   BufferDesc;// 上述的backbuffer
  DXGI_SAMPLE_DESC SampleDesc;//采样方式
  DXGI_USAGE       BufferUsage;//
  UINT             BufferCount;//缓冲区数量 1：双缓冲 2：三缓冲
  HWND             OutputWindow;//我们自己的输出窗口
  BOOL             Windowed;//是否窗口化
  DXGI_SWAP_EFFECT SwapEffect;//cpu访问后台缓冲区的方式
  UINT             Flags;//额外的标志
} DXGI_SWAP_CHAIN_DESC;

DXGI_SWAP_CHAIN_DESC swapChainDesc; 
    
ZeroMemory(&swapChainDesc, sizeof(DXGI_SWAP_CHAIN_DESC));

swapChainDesc.BufferDesc = bufferDesc;
swapChainDesc.SampleDesc.Count = 1;//每个像素多重采样的数量
swapChainDesc.SampleDesc.Quality = 0;//质量
swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
swapChainDesc.BufferCount = 1;
swapChainDesc.OutputWindow = hwnd; 
swapChainDesc.Windowed = TRUE; 
swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;

Creating the Device and SwapChain( D3D11CreateDeviceAndSwapChain() )

HRESULT D3D11CreateDeviceAndSwapChain(
  __in   IDXGIAdapter *pAdapter,//我们使用的adapter NULL使用默认的
  __in   D3D_DRIVER_TYPE DriverType,//direct3d要怎么实现 D3D_DRIVER_TYPE_HARDWARE将由gpu来实现
  __in   HMODULE Software,//软件栅格化的句柄 NULL
  __in   UINT Flags,//NULL
  __in   const D3D_FEATURE_LEVEL *pFeatureLevels,//NULL 使用最好的
  __in   UINT FeatureLevels,//NULL
  __in   UINT SDKVersion,//D3D11_SDK_VERSION
  __in   const DXGI_SWAP_CHAIN_DESC *pSwapChainDesc,//刚创建的交换链
  __out  IDXGISwapChain **ppSwapChain,//接收我们刚创建的交换链
  __out  ID3D11Device **ppDevice,//device
  __out  D3D_FEATURE_LEVEL *pFeatureLevel,//D3D_FEATURE_LEVEL 最高的
  __out  ID3D11DeviceContext **ppImmediateContext//device context
);

hr = D3D11CreateDeviceAndSwapChain(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, NULL, NULL, NULL,
    D3D11_SDK_VERSION, &swapChainDesc, &SwapChain, &d3d11Device, NULL, &d3d11DevCon);

Creating the BackBuffer( GetBuffer() )

HRESULT GetBuffer(
  [in]       UINT Buffer,//0
  [in]       REFIID riid,//ID3D11Texture2D 改变后缓冲区的借口类型的引用id
  [in, out]  void **ppSurface//backbuffer
);

ID3D11Texture2D* BackBuffer;
hr = SwapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ), (void**)&BackBuffer );

Creating the Render Target( ID3D11Device::CreateRenderTargetView() ) and release backbuffer

HRESULT CreateRenderTargetView(
  [in]   ID3D11Resource *pResource,//Back buffer
  [in]   const D3D11_RENDER_TARGET_VIEW_DESC *pDesc,//设null创建一个视图来访问mipmap为0的所有子资源
  [out]  ID3D11RenderTargetView **ppRTView//rendertarget

hr = d3d11Device->CreateRenderTargetView( BackBuffer, NULL, &renderTargetView );
BackBuffer->Release();

Set the Render Targets( ID3D11DeviceContext::OMSetRenderTargets() )

void OMSetRenderTargets(
  [in]  UINT NumViews,//需要绑定的View 数目 我们只有一个
  [in]  ID3D11RenderTargetView *const **ppRenderTargetViews,//需要绑定的view
  [in]  ID3D11DepthStencilView *pDepthStencilView//深度模板 没有设NULL
);

Clean Up

释放所有我们创建的com objects

void ReleaseObjects()
{
    //Release the COM Objects we created
    SwapChain->Release();
    d3d11Device->Release();
    d3dDevCon->Release();
}

Initialize Scene

初始化场景

bool InitScene()
{

    return true;
}

Update Scene

更新场景，如改变objects 位置，改变值，场景内的任何改变，本节只改变背景颜色

void UpdateScene()
{
    //Update the colors of our scene
    red += colormodr * 0.00005f;
    green += colormodg * 0.00002f;
    blue += colormodb * 0.00001f;

    if(red >= 1.0f || red <= 0.0f)
        colormodr *= -1;
    if(green >= 1.0f || green <= 0.0f)
        colormodg *= -1;
    if(blue >= 1.0f || blue <= 0.0f)
        colormodb *= -1;
}

Render Scene

DrawScene() render 我们的场景，该函数只渲染场景不更新场景 交换前后缓冲区，掉present会将back buffer 渲染到屏幕

void DrawScene()
{
    //Clear our backbuffer to the updated color
    D3DXCOLOR bgColor( red, green, blue, 1.0f );

    d3d11DevCon->ClearRenderTargetView(renderTargetView, bgColor);

    //Present the backbuffer to the screen 
    SwapChain->Present(0, 0);
}

messageloop()方法，先调用UpdateScene() 更新场景，然后然后掉DrawScene()把backbuffer渲染到屏幕

int messageloop(){
MSG msg;
ZeroMemory(&msg, sizeof(MSG));
while(true)
{
    BOOL PeekMessageL( 
        LPMSG lpMsg,
        HWND hWnd,
        UINT wMsgFilterMin,
        UINT wMsgFilterMax,
        UINT wRemoveMsg
        );

    if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
    {
        if (msg.message == WM_QUIT)
            break;
        TranslateMessage(&msg);    
        DispatchMessage(&msg);
    }
    else{
///////////////**************new**************////////////////////
        // run game code
        
        UpdateScene();
        DrawScene();
        
///////////////**************new**************////////////////////
    }
}
return msg.wParam;
}

Error Checking: 

DXGetErrorDescription 

需添加#include <DXErr.h>和 DXErr.lib

#pragma comment (lib, "DXErr.lib")
#include <DXErr.h>

...

bool InitializeDirect3d11App(HINSTANCE hInstance)
{
    HRESULT hr;

    //Describe our Buffer
    DXGI_MODE_DESC bufferDesc;

    ZeroMemory(&bufferDesc, sizeof(DXGI_MODE_DESC));

    bufferDesc.Width = Width;
    bufferDesc.Height = Height;
    bufferDesc.RefreshRate.Numerator = 60;
    bufferDesc.RefreshRate.Denominator = 1;
    bufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    bufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
    bufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;
    
    //Describe our SwapChain
    DXGI_SWAP_CHAIN_DESC swapChainDesc; 
        
    ZeroMemory(&swapChainDesc, sizeof(DXGI_SWAP_CHAIN_DESC));

    swapChainDesc.BufferDesc = bufferDesc;
    swapChainDesc.SampleDesc.Count = 1;
    swapChainDesc.SampleDesc.Quality = 0;
    swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    swapChainDesc.BufferCount = 1;
    swapChainDesc.OutputWindow = hwnd; 
    swapChainDesc.Windowed = TRUE; 
    swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;


    //Create our SwapChain
    hr = D3D11CreateDeviceAndSwapChain(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, NULL, NULL, NULL,
        D3D11_SDK_VERSION, &swapChainDesc, &SwapChain, &d3d11Device, NULL, &d3d11DevCon);
    if(FAILED(hr))
    {    
        MessageBox(NULL, DXGetErrorDescription(hr),
            TEXT(" D3D11CreateDeviceAndSwapChain"), MB_OK);    
        return 0;    
    }    

    //Create our BackBuffer
    ID3D11Texture2D* BackBuffer;
    hr = SwapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ), (void**)&BackBuffer );
    if(FAILED(hr))
    {    
        MessageBox(NULL, DXGetErrorDescription(hr),
            TEXT("SwapChain->GetBuffer"), MB_OK);    
        return 0;    
    }    

    //Create our Render Target
    hr = d3d11Device->CreateRenderTargetView( BackBuffer, NULL, &renderTargetView );
    BackBuffer->Release();
    if(FAILED(hr))
    {    
        MessageBox(NULL, DXGetErrorDescription(hr),
            TEXT("d3d11Device->CreateRenderTargetView"), MB_OK);    
        return 0;    
    }    

    //Set our Render Target
    d3d11DevCon->OMSetRenderTargets( 1, &renderTargetView, NULL );

    return true;
}

///////////////**************new**************////////////////////

#include <windows.h>
#include <d3d11.h>
#include <d3dx11.h>
#include <d3dx10.h>
#include <xnamath.h>

//Global Declarations//
IDXGISwapChain* SwapChain;
ID3D11Device* d3d11Device;
ID3D11DeviceContext* d3d11DevCon;
ID3D11RenderTargetView* renderTargetView;

float red = 0.0f;
float green = 0.0f;
float blue = 0.0f;
int colormodr = 1;
int colormodg = 1;
int colormodb = 1;

///////////////**************new**************////////////////////

LPCTSTR WndClassName = L"firstwindow";
HWND hwnd = NULL;

const int Width  = 300;
const int Height = 300;

///////////////**************new**************////////////////////

//Function Prototypes//
bool InitializeDirect3d11App(HINSTANCE hInstance);
void ReleaseObjects();
bool InitScene();
void UpdateScene();
void DrawScene();

///////////////**************new**************////////////////////

bool InitializeWindow(HINSTANCE hInstance,
                      int ShowWnd,
                      int width, int height,
                      bool windowed);
int messageloop();

LRESULT CALLBACK WndProc(HWND hWnd,
                         UINT msg,
                         WPARAM wParam,
                         LPARAM lParam);


int WINAPI WinMain(HINSTANCE hInstance,    //Main windows function
                   HINSTANCE hPrevInstance, 
                   LPSTR lpCmdLine,
                   int nShowCmd)
{

    if(!InitializeWindow(hInstance, nShowCmd, Width, Height, true))
    {
        MessageBox(0, L"Window Initialization - Failed",
            L"Error", MB_OK);
        return 0;
    }

    ///////////////**************new**************////////////////////

    if(!InitializeDirect3d11App(hInstance))    //Initialize Direct3D
    {
        MessageBox(0, L"Direct3D Initialization - Failed",
            L"Error", MB_OK);
        return 0;
    }

    if(!InitScene())    //Initialize our scene
    {
        MessageBox(0, L"Scene Initialization - Failed",
            L"Error", MB_OK);
        return 0;
    }

    messageloop();

    ReleaseObjects();

    ///////////////**************new**************////////////////////

    return 0;
}

bool InitializeWindow(HINSTANCE hInstance,
                      int ShowWnd,
                      int width, int height,
                      bool windowed)
{
    typedef struct _WNDCLASS {
        UINT cbSize;
        UINT style;
        WNDPROC lpfnWndProc;
        int cbClsExtra;
        int cbWndExtra;
        HANDLE hInstance;
        HICON hIcon;
        HCURSOR hCursor;
        HBRUSH hbrBackground;
        LPCTSTR lpszMenuName;
        LPCTSTR lpszClassName;
    } WNDCLASS;

    WNDCLASSEX wc;

    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = NULL;
    wc.cbWndExtra = NULL;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 2);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = WndClassName;
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    if (!RegisterClassEx(&wc))
    {
        MessageBox(NULL, L"Error registering class",    
            L"Error", MB_OK | MB_ICONERROR);
        return 1;
    }

    hwnd = CreateWindowEx(
        NULL,
        WndClassName,
        L"Window Title",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT,
        width, height,
        NULL,
        NULL,
        hInstance,
        NULL
        );

    if (!hwnd)
    {
        MessageBox(NULL, L"Error creating window",
            L"Error", MB_OK | MB_ICONERROR);
        return 1;
    }

    ShowWindow(hwnd, ShowWnd);
    UpdateWindow(hwnd);

    return true;
}

///////////////**************new**************////////////////////

bool InitializeDirect3d11App(HINSTANCE hInstance)
{
    //Describe our Buffer
    DXGI_MODE_DESC bufferDesc;

    ZeroMemory(&bufferDesc, sizeof(DXGI_MODE_DESC));

    bufferDesc.Width = Width;
    bufferDesc.Height = Height;
    bufferDesc.RefreshRate.Numerator = 60;
    bufferDesc.RefreshRate.Denominator = 1;
    bufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    bufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_UNSPECIFIED;
    bufferDesc.Scaling = DXGI_MODE_SCALING_UNSPECIFIED;

    //Describe our SwapChain
    DXGI_SWAP_CHAIN_DESC swapChainDesc; 

    ZeroMemory(&swapChainDesc, sizeof(DXGI_SWAP_CHAIN_DESC));

    swapChainDesc.BufferDesc = bufferDesc;
    swapChainDesc.SampleDesc.Count = 1;
    swapChainDesc.SampleDesc.Quality = 0;
    swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    swapChainDesc.BufferCount = 1;
    swapChainDesc.OutputWindow = hwnd; 
    swapChainDesc.Windowed = TRUE; 
    swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;


    //Create our SwapChain
    D3D11CreateDeviceAndSwapChain(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, NULL, NULL, NULL,
        D3D11_SDK_VERSION, &swapChainDesc, &SwapChain, &d3d11Device, NULL, &d3d11DevCon);

    //Create our BackBuffer
    ID3D11Texture2D* BackBuffer;
    SwapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ), (void**)&BackBuffer );

    //Create our Render Target
    d3d11Device->CreateRenderTargetView( BackBuffer, NULL, &renderTargetView );
    BackBuffer->Release();

    //Set our Render Target
    d3d11DevCon->OMSetRenderTargets( 1, &renderTargetView, NULL );

    return true;
}

void ReleaseObjects()
{
    //Release the COM Objects we created
    SwapChain->Release();
    d3d11Device->Release();
    d3d11DevCon->Release();
}
bool InitScene()
{

    return true;
}

void UpdateScene()
{
    //Update the colors of our scene
    red += colormodr * 0.00005f;
    green += colormodg * 0.00002f;
    blue += colormodb * 0.00001f;

    if(red >= 1.0f || red <= 0.0f)
        colormodr *= -1;
    if(green >= 1.0f || green <= 0.0f)
        colormodg *= -1;
    if(blue >= 1.0f || blue <= 0.0f)
        colormodb *= -1;
}

void DrawScene()
{
    //Clear our backbuffer to the updated color
    D3DXCOLOR bgColor( red, green, blue, 1.0f );

    d3d11DevCon->ClearRenderTargetView(renderTargetView, bgColor);

    //Present the backbuffer to the screen
    SwapChain->Present(0, 0);
}

///////////////**************new**************////////////////////

int messageloop(){
    MSG msg;
    ZeroMemory(&msg, sizeof(MSG));
    while(true)
    {
        BOOL PeekMessageL( 
            LPMSG lpMsg,
            HWND hWnd,
            UINT wMsgFilterMin,
            UINT wMsgFilterMax,
            UINT wRemoveMsg
            );

        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            if (msg.message == WM_QUIT)
                break;
            TranslateMessage(&msg);    
            DispatchMessage(&msg);
        }
        else{
            ///////////////**************new**************////////////////////
            // run game code

            UpdateScene();
            DrawScene();

            ///////////////**************new**************////////////////////
        }
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd,
                         UINT msg,
                         WPARAM wParam,
                         LPARAM lParam)
{
    switch( msg )
    {
    case WM_KEYDOWN:
        if( wParam == VK_ESCAPE ){
            DestroyWindow(hwnd);
        }
        return 0;

    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd,
        msg,
        wParam,
        lParam);
}

工程设置如下：