DX11 三维空间： depth信息与stencil信息

fxc.exe可以用于 编译fx的语法问题。

今天实现： 1.显示两个不同z值的不同纹理三角形  2.一个被覆盖掉一部分   

问题：为什么是ID3D11Texture2D 而不是ID3D11Buffer来创建 depthStencil  Buffer呢，规定吧，毕竟depthStencil需要知道view的width和height，是“结构化”的内存，buffer是非结构化的

http://lengbingteng.iteye.com/blog/1745472  第一段关于资源和视图的解释。

DX11 数据的分层：  model-View （什么数据，申请空间---数据的应用）， ID3D11Resource 确定数据成分是buffer还是texture     ID3D11View确定数据的应用是渲染显示还是depthStencil

Note：别忘记在 Render循环每帧开始 清空depth为1 ：g_pImmediateContext->ClearDepthStencilView(g_pDepthStencilView,D3D11_CLEAR_DEPTH,1.0f,0);

三种buffer：constant一般性

创建depthStencil的步骤：

1.定义： ID3D11Texture2D     ID3D11DepthStencilView 

2.初始化： 实现depthStencil的desc 申请数据空间，并且确定数据的作用。

Creates a depth buffer (a DepthStencil texture). It also creates a DepthStencilView of the depth buffer so that Direct3D 11 knows to use it as a Depth Stencil texture.

3.Render里，进行每帧绘制前的depth清空。

结果：

由于depth的作用，z值小的覆盖z大的，即0-1之间，1是最里面的

//--------------------------------------------------------------------------------------
// File: Tutorial03.cpp
//
// This application displays a triangle using Direct3D 11
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//--------------------------------------------------------------------------------------
#include <windows.h>
#include <d3d11.h>
#include <d3dx11.h>
#include <d3dcompiler.h>
#include <xnamath.h>
#include "resource.h"


//--------------------------------------------------------------------------------------
// Structures
//--------------------------------------------------------------------------------------
struct SimpleVertex
{
    XMFLOAT3 Pos;
    XMFLOAT2 Tex;//add texture position
};

struct  SimpleMatrix
{
    XMMATRIX mWorld;
    XMMATRIX mView;
    XMMATRIX mProject;
};

//--------------------------------------------------------------------------------------
// Global Variables
//--------------------------------------------------------------------------------------
HINSTANCE               g_hInst = NULL;
HWND                    g_hWnd = NULL;
D3D_DRIVER_TYPE         g_driverType = D3D_DRIVER_TYPE_NULL;
D3D_FEATURE_LEVEL       g_featureLevel = D3D_FEATURE_LEVEL_11_0;
ID3D11Device*           g_pd3dDevice = NULL;
ID3D11DeviceContext*    g_pImmediateContext = NULL;
IDXGISwapChain*         g_pSwapChain = NULL;
ID3D11RenderTargetView* g_pRenderTargetView = NULL;
ID3D11VertexShader*     g_pVertexShader = NULL;
ID3D11PixelShader*      g_pPixelShader = NULL;
ID3D11InputLayout*      g_pVertexLayout = NULL;
ID3D11Buffer*           g_pVertexBuffer = NULL;

ID3D11Buffer*           g_pIndexBuffer = NULL;

//BEGIN 添加纹理
ID3D11ShaderResourceView  *g_pTextureRV[2] ={NULL,NULL};
ID3D11SamplerState        *g_pSamplerLinear = NULL;
//end

//constant buffer
ID3D11Buffer             *g_pConstantMatrixBuffer = NULL;
XMMATRIX  g_pWorld;
XMMATRIX  g_View;
XMMATRIX  g_Project;
//

//BEGIN 添加depthStencil buffer和view 
ID3D11Texture2D  *g_pDepthStencilBuffer = NULL;//
ID3D11DepthStencilView *g_pDepthStencilView = NULL;
//end


//--------------------------------------------------------------------------------------
// Forward declarations
//--------------------------------------------------------------------------------------
HRESULT InitWindow( HINSTANCE hInstance, int nCmdShow );
HRESULT InitDevice();
void CleanupDevice();
LRESULT CALLBACK    WndProc( HWND, UINT, WPARAM, LPARAM );
void Render();


//--------------------------------------------------------------------------------------
// Entry point to the program. Initializes everything and goes into a message processing 
// loop. Idle time is used to render the scene.
//--------------------------------------------------------------------------------------
int WINAPI wWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLine, int nCmdShow )
{
    UNREFERENCED_PARAMETER( hPrevInstance );
    UNREFERENCED_PARAMETER( lpCmdLine );

    if( FAILED( InitWindow( hInstance, nCmdShow ) ) )
        return 0;

    if( FAILED( InitDevice() ) )
    {
        CleanupDevice();
        return 0;
    }

    // Main message loop
    MSG msg = {0};
    while( WM_QUIT != msg.message )
    {
        if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) )
        {
            TranslateMessage( &msg );
            DispatchMessage( &msg );
        }
        else
        {
            Render();
        }
    }

    CleanupDevice();

    return ( int )msg.wParam;
}


//--------------------------------------------------------------------------------------
// Register class and create window
//--------------------------------------------------------------------------------------
HRESULT InitWindow( HINSTANCE hInstance, int nCmdShow )
{
    // Register class
    WNDCLASSEX wcex;
    wcex.cbSize = sizeof( WNDCLASSEX );
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon( hInstance, ( LPCTSTR )IDI_TUTORIAL1 );
    wcex.hCursor = LoadCursor( NULL, IDC_ARROW );
    wcex.hbrBackground = ( HBRUSH )( COLOR_WINDOW + 1 );
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = L"TutorialWindowClass";
    wcex.hIconSm = LoadIcon( wcex.hInstance, ( LPCTSTR )IDI_TUTORIAL1 );
    if( !RegisterClassEx( &wcex ) )
        return E_FAIL;

    // Create window
    g_hInst = hInstance;
    RECT rc = { 0, 0, 640, 480 };
    AdjustWindowRect( &rc, WS_OVERLAPPEDWINDOW, FALSE );
    g_hWnd = CreateWindow( L"TutorialWindowClass", L"Direct3D 11 Tutorial 3: Shaders",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, rc.right - rc.left, rc.bottom - rc.top, NULL, NULL, hInstance,
        NULL );
    if( !g_hWnd )
        return E_FAIL;

    ShowWindow( g_hWnd, nCmdShow );

    return S_OK;
}


//--------------------------------------------------------------------------------------
// Helper for compiling shaders with D3DX11
//--------------------------------------------------------------------------------------
HRESULT CompileShaderFromFile( WCHAR* szFileName, LPCSTR szEntryPoint, LPCSTR szShaderModel, ID3DBlob** ppBlobOut )
{
    HRESULT hr = S_OK;

    DWORD dwShaderFlags = D3DCOMPILE_ENABLE_STRICTNESS;
#if defined( DEBUG ) || defined( _DEBUG )
    // Set the D3DCOMPILE_DEBUG flag to embed debug information in the shaders.
    // Setting this flag improves the shader debugging experience, but still allows 
    // the shaders to be optimized and to run exactly the way they will run in 
    // the release configuration of this program.
    dwShaderFlags |= D3DCOMPILE_DEBUG;
#endif

    ID3DBlob* pErrorBlob;
    hr = D3DX11CompileFromFile( szFileName, NULL, NULL, szEntryPoint, szShaderModel, 
        dwShaderFlags, 0, NULL, ppBlobOut, &pErrorBlob, NULL );
    if( FAILED(hr) )
    {
        if( pErrorBlob != NULL )
            OutputDebugStringA( (char*)pErrorBlob->GetBufferPointer() );
        if( pErrorBlob ) pErrorBlob->Release();
        return hr;
    }
    if( pErrorBlob ) pErrorBlob->Release();

    return S_OK;
}


//--------------------------------------------------------------------------------------
// Create Direct3D device and swap chain
//--------------------------------------------------------------------------------------
HRESULT InitDevice()
{
    HRESULT hr = S_OK;

    RECT rc;
    GetClientRect( g_hWnd, &rc );
    UINT width = rc.right - rc.left;
    UINT height = rc.bottom - rc.top;

    UINT createDeviceFlags = 0;
#ifdef _DEBUG
    createDeviceFlags |= D3D11_CREATE_DEVICE_DEBUG;
#endif

    D3D_DRIVER_TYPE driverTypes[] =
    {
        D3D_DRIVER_TYPE_HARDWARE,
        D3D_DRIVER_TYPE_WARP,
        D3D_DRIVER_TYPE_REFERENCE,
    };
    UINT numDriverTypes = ARRAYSIZE( driverTypes );

    D3D_FEATURE_LEVEL featureLevels[] =
    {
        D3D_FEATURE_LEVEL_11_0,
        D3D_FEATURE_LEVEL_10_1,
        D3D_FEATURE_LEVEL_10_0,
    };
    UINT numFeatureLevels = ARRAYSIZE( featureLevels );

    DXGI_SWAP_CHAIN_DESC sd;
    ZeroMemory( &sd, sizeof( sd ) );
    sd.BufferCount = 1;
    sd.BufferDesc.Width = width;
    sd.BufferDesc.Height = height;
    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    sd.BufferDesc.RefreshRate.Numerator = 60;
    sd.BufferDesc.RefreshRate.Denominator = 1;
    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    sd.OutputWindow = g_hWnd;
    sd.SampleDesc.Count = 1;
    sd.SampleDesc.Quality = 0;
    sd.Windowed = TRUE;

    for( UINT driverTypeIndex = 0; driverTypeIndex < numDriverTypes; driverTypeIndex++ )
    {
        g_driverType = driverTypes[driverTypeIndex];
        hr = D3D11CreateDeviceAndSwapChain( NULL, g_driverType, NULL, createDeviceFlags, featureLevels, numFeatureLevels,
            D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice, &g_featureLevel, &g_pImmediateContext );
        if( SUCCEEDED( hr ) )
            break;
    }
    if( FAILED( hr ) )
        return hr;

    // Create a render target view
    ID3D11Texture2D* pBackBuffer = NULL;
    hr = g_pSwapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ), ( LPVOID* )&pBackBuffer );
    if( FAILED( hr ) )
        return hr;

    hr = g_pd3dDevice->CreateRenderTargetView( pBackBuffer, NULL, &g_pRenderTargetView );
    pBackBuffer->Release();
    if( FAILED( hr ) )
        return hr;


    //BEGIN 添加深度蒙版buffer
    D3D11_TEXTURE2D_DESC descDepth;//为什么不用D3D11_BUFFER_DESC
    ZeroMemory( &descDepth, sizeof(descDepth) );
    descDepth.Width = width;
    descDepth.Height = height;
    descDepth.MipLevels = 1;
    descDepth.ArraySize = 1;
    descDepth.Format = DXGI_FORMAT_D24_UNORM_S8_UINT;
    descDepth.SampleDesc.Count = 1;
    descDepth.SampleDesc.Quality = 0;
    descDepth.Usage = D3D11_USAGE_DEFAULT;
    descDepth.BindFlags = D3D11_BIND_DEPTH_STENCIL;
    descDepth.CPUAccessFlags = 0;
    descDepth.MiscFlags = 0;

    hr = g_pd3dDevice->CreateTexture2D(&descDepth,NULL,&g_pDepthStencilBuffer);
    if (FAILED(hr))
    {
        return hr;
    }
    
    D3D11_DEPTH_STENCIL_VIEW_DESC descDSV;
    ZeroMemory( &descDSV, sizeof(descDSV) );
    descDSV.Format = descDepth.Format;
    descDSV.ViewDimension = D3D11_DSV_DIMENSION_TEXTURE2D;
    descDSV.Texture2D.MipSlice = 0;

    hr =  g_pd3dDevice->CreateDepthStencilView(g_pDepthStencilBuffer,&descDSV,&g_pDepthStencilView);
    if( FAILED( hr ) )
        return hr;

        g_pImmediateContext->OMSetRenderTargets( 1, &g_pRenderTargetView, g_pDepthStencilView );
    //END




    // Setup the viewport
    D3D11_VIEWPORT vp;
    vp.Width = (FLOAT)width;
    vp.Height = (FLOAT)height;
    vp.MinDepth = 0.0f;
    vp.MaxDepth = 1.0f;
    vp.TopLeftX = 0;
    vp.TopLeftY = 0;
    g_pImmediateContext->RSSetViewports( 1, &vp );

    // Compile the vertex shader
    ID3DBlob* pVSBlob = NULL;
    hr = CompileShaderFromFile( L"Tutorial03.fx", "VS", "vs_4_0", &pVSBlob );
    if( FAILED( hr ) )
    {
        MessageBox( NULL,
            L"VS Error.", L"Error", MB_OK );
        return hr;
    }

    // Create the vertex shader
    hr = g_pd3dDevice->CreateVertexShader( pVSBlob->GetBufferPointer(), pVSBlob->GetBufferSize(), NULL, &g_pVertexShader );
    if( FAILED( hr ) )
    {    
        pVSBlob->Release();
        return hr;
    }

    // Define the input layout
    D3D11_INPUT_ELEMENT_DESC layout[] =
    {
        { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
        { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0 },
    };
    UINT numElements = ARRAYSIZE( layout );

    // Create the input layout
    hr = g_pd3dDevice->CreateInputLayout( layout, numElements, pVSBlob->GetBufferPointer(),
        pVSBlob->GetBufferSize(), &g_pVertexLayout );
    pVSBlob->Release();
    if( FAILED( hr ) )
        return hr;

    // Set the input layout
    g_pImmediateContext->IASetInputLayout( g_pVertexLayout );

    // Compile the pixel shader
    ID3DBlob* pPSBlob = NULL;
    hr = CompileShaderFromFile( L"Tutorial03.fx", "PS", "ps_4_0", &pPSBlob );
    if( FAILED( hr ) )
    {
        MessageBox( NULL,
            L"PS Error.", L"Error", MB_OK );
        return hr;
    }

    // Create the pixel shader
    hr = g_pd3dDevice->CreatePixelShader( pPSBlob->GetBufferPointer(), pPSBlob->GetBufferSize(), NULL, &g_pPixelShader );
    pPSBlob->Release();
    if( FAILED( hr ) )
        return hr;

    // Create vertex buffer
    SimpleVertex vertices[] =
    {
        {XMFLOAT3( -1.0f, 1.0f, -1.0f ),XMFLOAT2(0.0f,0.0f)},
        {XMFLOAT3( 1.0f, -1.0f, -1.0f  ),XMFLOAT2(1.0f,0.0f)},
        {XMFLOAT3( -1.0f, -1.0f, -1.0f ),XMFLOAT2(1.0f,1.0f)},


        {XMFLOAT3( -0.5f, 1.5f, -0.8f ),XMFLOAT2(0.0f,0.0f)},
        {XMFLOAT3( 1.5f, -0.5f, -0.8f  ),XMFLOAT2(1.0f,0.0f)},
        {XMFLOAT3( -0.5f, -0.5f, -0.8f ),XMFLOAT2(1.0f,1.0f)},

    };
    D3D11_BUFFER_DESC bd;
    ZeroMemory( &bd, sizeof(bd) );
    bd.Usage = D3D11_USAGE_DEFAULT;
    bd.ByteWidth = sizeof( SimpleVertex ) * 6;
    bd.BindFlags = D3D11_BIND_VERTEX_BUFFER;
    bd.CPUAccessFlags = 0;
    D3D11_SUBRESOURCE_DATA InitData;
    ZeroMemory( &InitData, sizeof(InitData) );
    InitData.pSysMem = vertices;
    hr = g_pd3dDevice->CreateBuffer( &bd, &InitData, &g_pVertexBuffer );
    if( FAILED( hr ) )
        return hr;

    // Set vertex buffer
    UINT stride = sizeof( SimpleVertex );
    UINT offset = 0;
    g_pImmediateContext->IASetVertexBuffers( 0, 1, &g_pVertexBuffer, &stride, &offset );

    WORD indices[]=
    {
        0,1,2,  

        3,4,5
    };
    bd.Usage = D3D11_USAGE_DEFAULT;
    bd.ByteWidth = sizeof( WORD ) * 6;
    bd.BindFlags = D3D11_BIND_INDEX_BUFFER;
    bd.CPUAccessFlags = 0;
    InitData.pSysMem = indices;
    hr = g_pd3dDevice->CreateBuffer( &bd, &InitData, &g_pIndexBuffer );
    if( FAILED( hr ) )
        return hr;

    // Set index buffer
    g_pImmediateContext->IASetIndexBuffer( g_pIndexBuffer, DXGI_FORMAT_R16_UINT, 0 );

    // Set primitive topology
    g_pImmediateContext->IASetPrimitiveTopology( D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST );

    bd.Usage = D3D11_USAGE_DEFAULT;
    bd.ByteWidth = sizeof(SimpleMatrix);
    bd.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
    bd.CPUAccessFlags = 0;
    hr = g_pd3dDevice->CreateBuffer( &bd, NULL, &g_pConstantMatrixBuffer );
    if( FAILED( hr ) )
        return hr;

    //BEGIN
    //载入纹理资源
    hr = D3DX11CreateShaderResourceViewFromFile(g_pd3dDevice,L"seafloor.dds",NULL,NULL,&g_pTextureRV[0],NULL);
    if (FAILED(hr))
    {
        return hr;
    }
    //载入第二个纹理
    hr = D3DX11CreateShaderResourceViewFromFile(g_pd3dDevice,L"grass.dds",NULL,NULL,&g_pTextureRV[1],NULL);
    if (FAILED(hr))
    {
        return hr;
    }

    //创建纹理采样状态
    D3D11_SAMPLER_DESC sampDesc;
    ZeroMemory(&sampDesc,sizeof(sampDesc));
    sampDesc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
    sampDesc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
    sampDesc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
    sampDesc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP;
    sampDesc.ComparisonFunc = D3D11_COMPARISON_NEVER;
    sampDesc.MinLOD = 0;
    sampDesc.MaxLOD = D3D11_FLOAT32_MAX;
    hr = g_pd3dDevice->CreateSamplerState(&sampDesc,&g_pSamplerLinear);

    if( FAILED( hr ) )
        return hr;


    //END

    // Initialize the world matrix
    g_pWorld = XMMatrixIdentity();

    // Initialize the view matrix
    XMVECTOR Eye = XMVectorSet( 0.0f, 1.0f, -5.0f, 0.0f );
    XMVECTOR At = XMVectorSet( 0.0f, 1.0f, 0.0f, 0.0f );
    XMVECTOR Up = XMVectorSet( 0.0f, 1.0f, 0.0f, 0.0f );
    g_View = XMMatrixLookAtLH( Eye, At, Up );

    // Initialize the projection matrix
    g_Project = XMMatrixPerspectiveFovLH( XM_PIDIV2, width / (FLOAT)height, 0.01f, 100.0f );

        
    return S_OK;
}


//--------------------------------------------------------------------------------------
// Clean up the objects we've created
//--------------------------------------------------------------------------------------
void CleanupDevice()
{
    if (g_pSamplerLinear)
    {
        g_pSamplerLinear->Release();
    }
    if (g_pConstantMatrixBuffer)
    {
        g_pConstantMatrixBuffer->Release();
    }
    if( g_pImmediateContext ) g_pImmediateContext->ClearState();
    if( g_pVertexBuffer ) g_pVertexBuffer->Release();
    if( g_pVertexLayout ) g_pVertexLayout->Release();
    if( g_pVertexShader ) g_pVertexShader->Release();
    if( g_pPixelShader ) g_pPixelShader->Release();
    if( g_pRenderTargetView ) g_pRenderTargetView->Release();
    if( g_pSwapChain ) g_pSwapChain->Release();
    if( g_pImmediateContext ) g_pImmediateContext->Release();
    if( g_pd3dDevice ) g_pd3dDevice->Release();
}


//--------------------------------------------------------------------------------------
// Called every time the application receives a message
//--------------------------------------------------------------------------------------
LRESULT CALLBACK WndProc( HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam )
{
    PAINTSTRUCT ps;
    HDC hdc;

    switch( message )
    {
    case WM_PAINT:
        hdc = BeginPaint( hWnd, &ps );
        EndPaint( hWnd, &ps );
        break;

    case WM_DESTROY:
        PostQuitMessage( 0 );
        break;

    default:
        return DefWindowProc( hWnd, message, wParam, lParam );
    }

    return 0;
}


//--------------------------------------------------------------------------------------
// Render a frame
//--------------------------------------------------------------------------------------
void Render()
{
    // Clear the back buffer 
    float ClearColor[4] = { 0.0f, 0.125f, 0.3f, 1.0f }; // red,green,blue,alpha
    g_pImmediateContext->ClearRenderTargetView( g_pRenderTargetView, ClearColor );
    g_pImmediateContext->ClearDepthStencilView(g_pDepthStencilView,D3D11_CLEAR_DEPTH,1.0f,0);

    //
    // Update variables
    //
    SimpleMatrix cb;
    cb.mWorld = XMMatrixTranspose( g_pWorld );
    cb.mView = XMMatrixTranspose( g_View );
    cb.mProject = XMMatrixTranspose( g_Project );
    g_pImmediateContext->UpdateSubresource( g_pConstantMatrixBuffer, 0, NULL, &cb, 0, 0 );
    // Render a triangle
    g_pImmediateContext->VSSetShader( g_pVertexShader, NULL, 0 );
    g_pImmediateContext->VSSetConstantBuffers(0,1,&g_pConstantMatrixBuffer);

    g_pImmediateContext->PSSetShader( g_pPixelShader, NULL, 0 );
    //BEGIN  提供纹理资源和采样状态给PixelShader使用
    g_pImmediateContext->PSSetShaderResources(0,1,&g_pTextureRV[0]);
    g_pImmediateContext->PSSetSamplers(0,1,&g_pSamplerLinear);
    //END
    g_pImmediateContext->DrawIndexed( 3, 0 , 0 );


    g_pImmediateContext->PSSetShaderResources(0,1,&g_pTextureRV[1]);
    g_pImmediateContext->DrawIndexed(3,3,0);


    // Present the information rendered to the back buffer to the front buffer (the screen)
    g_pSwapChain->Present( 0, 0 );
}

fx代码没有变。