初始化D3D我们需要以下几步步
一.创建driver type,feature level
driver type分为3种类-hardware,warp以及reference,代表GPU,CPU模拟和软件模拟,性能依次下降
feature level代表dx的等级,从11到10依次下调
按driver type以及feature level,从高到低遍历,找到合适的跳出.
//Specifying the driver type and feature levels
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_1,
D3D_FEATURE_LEVEL_11_0,
D3D_FEATURE_LEVEL_10_1,
D3D_FEATURE_LEVEL_10_0,
};
UINT numFeatureLevels = ARRAYSIZE( featureLevels );
for( UINT driverTypeIndex = 0; driverTypeIndex < numDriverTypes; driverTypeIndex++ )
{
g_driverType = driverTypes[driverTypeIndex];
hr = D3D11CreateDevice( nullptr, g_driverType, nullptr, createDeviceFlags, featureLevels, numFeatureLevels,
D3D11_SDK_VERSION, &g_pd3dDevice, &g_featureLevel, &g_pImmediateContext );
if ( hr == E_INVALIDARG )
{
// DirectX 11.0 platforms will not recognize D3D_FEATURE_LEVEL_11_1 so we need to retry without it
hr = D3D11CreateDevice( nullptr, g_driverType, nullptr, createDeviceFlags, &featureLevels[1], numFeatureLevels - 1,
D3D11_SDK_VERSION, &g_pd3dDevice, &g_featureLevel, &g_pImmediateContext );
}
if( SUCCEEDED( hr ) )
break;
}
if( FAILED( hr ) )
return hr;
二.创建交换链
Direct3D 11 包含一个称为 DirectX 图形基础结构 (DXGI) 的设备 API。使用 DXGI 接口，我们可以控制交换链的配置方式，并可设置共享设备。初始化 Direct3D 时，我们会在这一步骤中使用 DXGI 来创建交换链。创建设备之后，我们便可以跟随一个接口链回到 DXGI 适配器。
Direct3D 设备为 DXGI 实现一个接口。首先，我们需要获取该接口并使用该接口来请求托管设备的 DXGI 适配器。然后，我们使用 DXGI 适配器来创建 DXGI 工厂。
// Obtain DXGI factory from device (since we used nullptr for pAdapter above)
IDXGIFactory1* dxgiFactory = nullptr;
{
IDXGIDevice* dxgiDevice = nullptr; //为 DXGI 实现一个接口
hr = g_pd3dDevice->QueryInterface( __uuidof(IDXGIDevice), reinterpret_cast<void**>(&dxgiDevice) );
if (SUCCEEDED(hr))
{
IDXGIAdapter* adapter = nullptr;
hr = dxgiDevice->GetAdapter(&adapter); //DXGI 适配器
if (SUCCEEDED(hr))
{
hr = adapter->GetParent( __uuidof(IDXGIFactory1), reinterpret_cast<void**>(&dxgiFactory) );//使用 DXGI 适配器来创建 DXGI 工厂。
adapter->Release();
}
dxgiDevice->Release();
}
}
if (FAILED(hr))
return hr;
一条交换链是一个设备渲染目标的集合,每个设备至少有一条交换链
渲染目标可以是颜色缓冲区,深度缓冲区或者模版缓冲区
一般来说有两个颜色缓冲区-屏幕缓冲区和背景缓冲区(双缓冲)
交换链结构体有这些成员：
sd.BufferCount = 1;//不知道为什么是1
sd.BufferDesc.Width = width;//client area的长宽
sd.BufferDesc.Height = height;
sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;//格式
sd.BufferDesc.RefreshRate.Numerator = 60;//刷新率
sd.BufferDesc.RefreshRate.Denominator = 1;
sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;//可输出渲染
sd.OutputWindow = g_hWnd;//本窗口句柄
sd.SampleDesc.Count = 1;//抗锯齿
sd.SampleDesc.Quality = 0;//抗锯齿
sd.Windowed = TRUE;
代码：
// Create swap chain
IDXGIFactory2* dxgiFactory2 = nullptr;
hr = dxgiFactory->QueryInterface( __uuidof(IDXGIFactory2), reinterpret_cast<void**>(&dxgiFactory2) );
if ( dxgiFactory2 )
{
// DirectX 11.1 or later
hr = g_pd3dDevice->QueryInterface( __uuidof(ID3D11Device1), reinterpret_cast<void**>(&g_pd3dDevice1) );
if (SUCCEEDED(hr))
{
(void) g_pImmediateContext->QueryInterface( __uuidof(ID3D11DeviceContext1), reinterpret_cast<void**>(&g_pImmediateContext1) );
}
DXGI_SWAP_CHAIN_DESC1 sd;
ZeroMemory(&sd, sizeof(sd));
sd.Width = width;
sd.Height = height;
sd.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
sd.SampleDesc.Count = 1;
sd.SampleDesc.Quality = 0;
sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
sd.BufferCount = 1;
hr = dxgiFactory2->CreateSwapChainForHwnd( g_pd3dDevice, g_hWnd, &sd, nullptr, nullptr, &g_pSwapChain1 );
if (SUCCEEDED(hr))
{
hr = g_pSwapChain1->QueryInterface( __uuidof(IDXGISwapChain), reinterpret_cast<void**>(&g_pSwapChain) );
}
dxgiFactory2->Release();
}
else
{
// DirectX 11.0 systems
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;
hr = dxgiFactory->CreateSwapChain( g_pd3dDevice, &sd, &g_pSwapChain );
}
// Note this tutorial doesn‘t handle full-screen swapchains so we block the ALT+ENTER shortcut
dxgiFactory->MakeWindowAssociation( g_hWnd, DXGI_MWA_NO_ALT_ENTER );
dxgiFactory->Release();
if (FAILED(hr))
return hr;
三 创建Render Target View
// Create a render target view
ID3D11Texture2D* pBackBuffer = nullptr;
hr = g_pSwapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ), reinterpret_cast<void**>( &pBackBuffer ) );
if( FAILED( hr ) )
return hr;
hr = g_pd3dDevice->CreateRenderTargetView( pBackBuffer, nullptr, &g_pRenderTargetView );
pBackBuffer->Release();
if( FAILED( hr ) )
return hr;
g_pImmediateContext->OMSetRenderTargets( 1, &g_pRenderTargetView, nullptr );
四 设置ViewPort
设置渲染视图,双人的可以设置两个视图之类的
// 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 );
五 渲染到屏幕
g_pImmediateContext->ClearRenderTargetView( g_pRenderTargetView, Colors::MidnightBlue );
g_pSwapChain->Present( 0, 0 );
六 释放
if( g_pImmediateContext ) g_pImmediateContext->ClearState();
if( g_pRenderTargetView ) g_pRenderTargetView->Release();
if( g_pSwapChain1 ) g_pSwapChain1->Release();
if( g_pSwapChain ) g_pSwapChain->Release();
if( g_pImmediateContext1 ) g_pImmediateContext1->Release();
if( g_pImmediateContext ) g_pImmediateContext->Release();
if( g_pd3dDevice1 ) g_pd3dDevice1->Release();
if( g_pd3dDevice ) g_pd3dDevice->Release();
时间： 2024-04-26 12:37:56