Direct3D 11教程6：光照
原文地址：http://msdn.microsoft.com/en-us/library/ff729723.aspx。
概览
在前面的教程中，因为所有物体都是以相同的方式被光照亮，因此还不够真实。本教程将介绍简单的光照概念以及如何施加光照，这个技术将使用Lambert光照模型。
这个教程的会在前一个示例的基础上包含一个光源，光源链接在轨道运行的立方体上，光照的效果可以在中央立方体表面上看到。
源代码
(SDK root)\Samples\C++\Direct3D11\Tutorials\Tutorial06
光照
在本教程中将介绍最简单的光照类型：Lambert光照。Lambert光照具有相同的光照强度而不考虑离开光源的距离。当光照射到表面时，反射光的强度根据光在表面上的入射角大小进行计算。当光线垂直射向表面，反射回所有光照，具有最大的光强。当入射角变大时，光的强度也会减弱。
要计算表面的光照强度，必须计算光照方向和表面法线之间的夹角。法线定义为垂直于平面的一个矢量，角度的计算只需使用一个简单的点乘即可，返回的结果是光照方向矢量在法线上的投影长度。入射角越大，投影长度越短，这样，我们就有一个正确的方法调整漫反射光照。
本教程使用的光源接近于单向光，表示光源的矢量决定了光线的方向。因为这是一个近似，所以物体的位置无关紧要，我们认为光照方向都是一样的。这种光源的一个例子就是太阳，在一个场景中，太阳光总是被认为是同一方向的。
另一种类型的光源是点光源，从光源中心发出光线；还有一种是聚光灯，它发出的光线具有方向性但又不是均匀照射所有物体。
初始化光照
在本教程中，我们使用两个光源。一个静止放置在立方体的上后方，另一个绕着它旋转。
因为光照是由shader进行计算的，所以必须首先声明变量然后将它们与technique绑定。在本例中，我们只需光照方向和颜色值。第一个光源为灰色不移动，第二个是一个沿轨道绕行的红色光源。
// 设置光源参数
XMFLOAT4 vLightDirs[2] =
{
XMFLOAT4( -0.577f, 0.577f, -0.577f, 1.0f ),
XMFLOAT4( 0.0f, 0.0f, -1.0f, 1.0f ),
};
XMFLOAT4 vLightColors[2] =
{
XMFLOAT4( 0.5f, 0.5f, 0.5f, 1.0f ),
XMFLOAT4( 0.5f, 0.0f, 0.0f, 1.0f )
};
第二个光源还像上一个教程中的立方体那样旋转，施加的矩阵会改变光照方向，让光照总是朝向中心。注意，XMVec3Transform方法用来在矢量上乘以矩阵。在前面的教程中，我们只是将变换矩阵乘进世界矩阵中，然后传递到shader用于变换；但本例中基于简化的考虑，我们在CPU中对光源进行世界变换。
// 使第2个正方体绕原点旋转 // Rotate the second light around the origin XMMATRIX mRotate = XMMatrixRotationY( -2.0f * t ); XMVECTOR vLightDir = XMLoadFloat4( &vLightDirs[1] ); vLightDir = XMVector3Transform( vLightDir, mRotate ); XMStoreFloat4( &vLightDirs[1], vLightDir );
光照方向和颜色都传递到shader中，对应的变量被调用并设置，参数被传递。
// // 更新矩阵和光源变量 // ConstantBuffer cb1; cb1.mWorld = XMMatrixTranspose( g_World ); cb1.mView = XMMatrixTranspose( g_View ); cb1.mProjection = XMMatrixTranspose( g_Projection ); cb1.vLightDir[0] = vLightDirs[0]; cb1.vLightDir[1] = vLightDirs[1]; cb1.vLightColor[0] = vLightColors[0]; cb1.vLightColor[1] = vLightColors[1]; cb1.vOutputColor = XMFLOAT4(0, 0, 0, 0); g_pImmediateContext->UpdateSubresource( g_pConstantBuffer, 0, NULL, &cb1, 0, 0 );
在像素着色器中绘制光照
设置了所有数据我们就可以计算每一个像素的lambert光照因子了，使用的是上面提到过的点乘规则。
有了点乘结果后，就可以将这个结果乘以光照颜色计算光照的影响了。这个值被传递到saturate方法，这个方法将结果限定在[0,1]区间。最后，两个光源的效果会相加获得最终的像素颜色。
物体表面材质并没有考虑在光照计算中，表面的最终颜色只包含光照颜色。
//
// Pixel Shader
//
float4 PS( PS_INPUT input) : SV_Target
{
float4 finalColor = 0;
//对两个光源进行NdotL光照计算
for(int i=0; i<2; i++)
{
finalColor += saturate( dot( (float3)vLightDir[i],input.Norm) * vLightColor[i] );
}
return finalColor;
}
经过像素着色器的处理，像素的颜色就被光照调制，你可以在中央立方体表面看到光照效果。因为本例中同一表面的法线方向相同，所以同一表面的光照强度相同。漫反射（Diffuse）光照是一个非常简单容易的光照模型，你可以使用更复杂的光照模型实现更加真实的效果。
完整代码
#include <windows.h>
#include <d3d11.h>
#include <d3dcompiler.h>
#include <directxmath.h>
#include "resource.h"
using namespace DirectX;
//--------------------------------------------------------------------------------------
// 顶点结构
//--------------------------------------------------------------------------------------
struct SimpleVertex
{
XMFLOAT3 Pos;
XMFLOAT3 Normal;
};
struct ConstantBuffer
{
XMMATRIX mWorld;
XMMATRIX mView;
XMMATRIX mProjection;
XMFLOAT4 vLightDir[2];
XMFLOAT4 vLightColor[2];
XMFLOAT4 vOutputColor;
};
//--------------------------------------------------------------------------------------
// 全局变量
//--------------------------------------------------------------------------------------
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;
ID3D11Texture2D* g_pDepthStencil = NULL;
ID3D11DepthStencilView* g_pDepthStencilView = NULL;
ID3D11VertexShader* g_pVertexShader = NULL;
ID3D11PixelShader* g_pPixelShader = NULL;
ID3D11PixelShader* g_pPixelShaderSolid = NULL;
ID3D11InputLayout* g_pVertexLayout = NULL;
ID3D11Buffer* g_pVertexBuffer = NULL;
ID3D11Buffer* g_pIndexBuffer = NULL;
ID3D11Buffer* g_pConstantBuffer = NULL;
XMMATRIX g_World;
XMMATRIX g_View;
XMMATRIX g_Projection;
//--------------------------------------------------------------------------------------
// 函数声明
//--------------------------------------------------------------------------------------
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;
}
//--------------------------------------------------------------------------------------
// 注册和创建窗口
//--------------------------------------------------------------------------------------
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 6", 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 D3DCompile
//
// With VS 11, we could load up prebuilt .cso files instead...
//--------------------------------------------------------------------------------------
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 = D3DCompileFromFile( szFileName, NULL, NULL, szEntryPoint, szShaderModel,
dwShaderFlags, 0, ppBlobOut, &pErrorBlob );
if( FAILED(hr) )
{
if( pErrorBlob != NULL )
OutputDebugStringA( (char*)pErrorBlob->GetBufferPointer() );
if( pErrorBlob ) pErrorBlob->Release();
return hr;
}
if( pErrorBlob ) pErrorBlob->Release();
return S_OK;
}
//--------------------------------------------------------------------------------------
// 创建Direct3D设备和交换链
//--------------------------------------------------------------------------------------
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;
// Create depth stencil texture
D3D11_TEXTURE2D_DESC descDepth;
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_pDepthStencil );
if( FAILED( hr ) )
return hr;
// Create the depth stencil view
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_pDepthStencil, &descDSV, &g_pDepthStencilView );
if( FAILED( hr ) )
return hr;
g_pImmediateContext->OMSetRenderTargets( 1, &g_pRenderTargetView, g_pDepthStencilView );
// 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"Tutorial06.fx", "VS", "vs_4_0", &pVSBlob );
if( FAILED( hr ) )
{
MessageBox( NULL,
L"The FX file cannot be compiled. Please run this executable from the
directory that contains the FX file.", 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 },
{ "NORMAL", 0, DXGI_FORMAT_R32G32B32_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"Tutorial06.fx", "PS", "ps_4_0", &pPSBlob );
if( FAILED( hr ) )
{
MessageBox( NULL,
L"The FX file cannot be compiled. Please run this executable from the directory
that contains the FX file.", 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;
// Compile the pixel shader
pPSBlob = NULL;
hr = CompileShaderFromFile( L"Tutorial06.fx", "PSSolid", "ps_4_0", &pPSBlob );
if( FAILED( hr ) )
{
MessageBox( NULL,
L"The FX file cannot be compiled. Please run this executable from the directory
that contains the FX file.", L"Error", MB_OK );
return hr;
}
// Create the pixel shader
hr = g_pd3dDevice->CreatePixelShader( pPSBlob->GetBufferPointer(), pPSBlob->GetBufferSize(), NULL, &g_pPixelShaderSolid );
pPSBlob->Release();
if( FAILED( hr ) )
return hr;
// Create vertex buffer
SimpleVertex vertices[] =
{
{ XMFLOAT3( -1.0f, 1.0f, -1.0f ), XMFLOAT3( 0.0f, 1.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, -1.0f ), XMFLOAT3( 0.0f, 1.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, 1.0f ), XMFLOAT3( 0.0f, 1.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, 1.0f, 1.0f ), XMFLOAT3( 0.0f, 1.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, -1.0f, -1.0f ), XMFLOAT3( 0.0f, -1.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, -1.0f, -1.0f ), XMFLOAT3( 0.0f, -1.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, -1.0f, 1.0f ), XMFLOAT3( 0.0f, -1.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, -1.0f, 1.0f ), XMFLOAT3( 0.0f, -1.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, -1.0f, 1.0f ), XMFLOAT3( -1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, -1.0f, -1.0f ), XMFLOAT3( -1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, 1.0f, -1.0f ), XMFLOAT3( -1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, 1.0f, 1.0f ), XMFLOAT3( -1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, -1.0f, 1.0f ), XMFLOAT3( 1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, -1.0f, -1.0f ), XMFLOAT3( 1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, -1.0f ), XMFLOAT3( 1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, 1.0f ), XMFLOAT3( 1.0f, 0.0f, 0.0f ) },
{ XMFLOAT3( -1.0f, -1.0f, -1.0f ), XMFLOAT3( 0.0f, 0.0f, -1.0f ) },
{ XMFLOAT3( 1.0f, -1.0f, -1.0f ), XMFLOAT3( 0.0f, 0.0f, -1.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, -1.0f ), XMFLOAT3( 0.0f, 0.0f, -1.0f ) },
{ XMFLOAT3( -1.0f, 1.0f, -1.0f ), XMFLOAT3( 0.0f, 0.0f, -1.0f ) },
{ XMFLOAT3( -1.0f, -1.0f, 1.0f ), XMFLOAT3( 0.0f, 0.0f, 1.0f ) },
{ XMFLOAT3( 1.0f, -1.0f, 1.0f ), XMFLOAT3( 0.0f, 0.0f, 1.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, 1.0f ), XMFLOAT3( 0.0f, 0.0f, 1.0f ) },
{ XMFLOAT3( -1.0f, 1.0f, 1.0f ), XMFLOAT3( 0.0f, 0.0f, 1.0f ) },
};
D3D11_BUFFER_DESC bd;
ZeroMemory( &bd, sizeof(bd) );
bd.Usage = D3D11_USAGE_DEFAULT;
bd.ByteWidth = sizeof( SimpleVertex ) * 24;
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 );
// Create index buffer
WORD indices[] =
{
3,1,0,
2,1,3,
6,4,5,
7,4,6,
11,9,8,
10,9,11,
14,12,13,
15,12,14,
19,17,16,
18,17,19,
22,20,21,
23,20,22
};
bd.Usage = D3D11_USAGE_DEFAULT;
bd.ByteWidth = sizeof( WORD ) * 36; // 36 vertices needed for 12 triangles in a triangle list
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 );
// Create the constant buffer
bd.Usage = D3D11_USAGE_DEFAULT;
bd.ByteWidth = sizeof(ConstantBuffer);
bd.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
bd.CPUAccessFlags = 0;
hr = g_pd3dDevice->CreateBuffer( &bd, NULL, &g_pConstantBuffer );
if( FAILED( hr ) )
return hr;
// Initialize the world matrices
g_World = XMMatrixIdentity();
// Initialize the view matrix
XMVECTOR Eye = XMVectorSet( 0.0f, 4.0f, -10.0f, 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_Projection = XMMatrixPerspectiveFovLH( XM_PIDIV4, width / (FLOAT)height, 0.01f, 100.0f );
return S_OK;
}
//--------------------------------------------------------------------------------------
// Clean up the objects we've created
//--------------------------------------------------------------------------------------
void CleanupDevice()
{
if( g_pImmediateContext ) g_pImmediateContext->ClearState();
if( g_pConstantBuffer ) g_pConstantBuffer->Release();
if( g_pVertexBuffer ) g_pVertexBuffer->Release();
if( g_pIndexBuffer ) g_pIndexBuffer->Release();
if( g_pVertexLayout ) g_pVertexLayout->Release();
if( g_pVertexShader ) g_pVertexShader->Release();
if( g_pPixelShaderSolid ) g_pPixelShaderSolid->Release();
if( g_pPixelShader ) g_pPixelShader->Release();
if( g_pDepthStencil ) g_pDepthStencil->Release();
if( g_pDepthStencilView ) g_pDepthStencilView->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()
{
// Update our time
static float t = 0.0f;
if( g_driverType == D3D_DRIVER_TYPE_REFERENCE )
{
t += ( float )XM_PI * 0.0125f;
}
else
{
static DWORD dwTimeStart = 0;
DWORD dwTimeCur = GetTickCount();
if( dwTimeStart == 0 )
dwTimeStart = dwTimeCur;
t = ( dwTimeCur - dwTimeStart ) / 1000.0f;
}
// Rotate cube around the origin
g_World = XMMatrixRotationY( t );
// 设置光源参数
XMFLOAT4 vLightDirs[2] =
{
XMFLOAT4( -0.577f, 0.577f, -0.577f, 1.0f ),
XMFLOAT4( 0.0f, 0.0f, -1.0f, 1.0f ),
};
XMFLOAT4 vLightColors[2] =
{
XMFLOAT4( 0.5f, 0.5f, 0.5f, 1.0f ),
XMFLOAT4( 0.5f, 0.0f, 0.0f, 1.0f )
};
// 使第2个光源绕原点旋转
XMMATRIX mRotate = XMMatrixRotationY( -2.0f * t );
XMVECTOR vLightDir = XMLoadFloat4( &vLightDirs[1] );
vLightDir = XMVector3Transform( vLightDir, mRotate );
XMStoreFloat4( &vLightDirs[1], vLightDir );
//
// 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 );
//
// Clear the depth buffer to 1.0 (max depth)
//
g_pImmediateContext->ClearDepthStencilView( g_pDepthStencilView, D3D11_CLEAR_DEPTH, 1.0f, 0 );
//
// 更新矩阵和光源变量
//
ConstantBuffer cb1;
cb1.mWorld = XMMatrixTranspose( g_World );
cb1.mView = XMMatrixTranspose( g_View );
cb1.mProjection = XMMatrixTranspose( g_Projection );
cb1.vLightDir[0] = vLightDirs[0];
cb1.vLightDir[1] = vLightDirs[1];
cb1.vLightColor[0] = vLightColors[0];
cb1.vLightColor[1] = vLightColors[1];
cb1.vOutputColor = XMFLOAT4(0, 0, 0, 0);
g_pImmediateContext->UpdateSubresource( g_pConstantBuffer, 0, NULL, &cb1, 0, 0 );
//
// 绘制立方体
//
g_pImmediateContext->VSSetShader( g_pVertexShader, NULL, 0 );
g_pImmediateContext->VSSetConstantBuffers( 0, 1, &g_pConstantBuffer );
g_pImmediateContext->PSSetShader( g_pPixelShader, NULL, 0 );
g_pImmediateContext->PSSetConstantBuffers( 0, 1, &g_pConstantBuffer );
g_pImmediateContext->DrawIndexed( 36, 0, 0 );
//
// 绘制两个光源
//
for( int m = 0; m < 2; m++ )
{
XMMATRIX mLight = XMMatrixTranslationFromVector( 5.0f * XMLoadFloat4( &vLightDirs[m] ) );
XMMATRIX mLightScale = XMMatrixScaling( 0.2f, 0.2f, 0.2f );
mLight = mLightScale * mLight;
// 更新世界矩阵to reflect the current light
cb1.mWorld = XMMatrixTranspose( mLight );
cb1.vOutputColor = vLightColors[m];
g_pImmediateContext->UpdateSubresource( g_pConstantBuffer, 0, NULL, &cb1, 0, 0 );
g_pImmediateContext->PSSetShader( g_pPixelShaderSolid, NULL, 0 );
g_pImmediateContext->DrawIndexed( 36, 0, 0 );
}
//
// Present our back buffer to our front buffer
//
g_pSwapChain->Present( 0, 0 );
}
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发布时间：2012/7/8 9:11:13 阅读次数：7152
