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颜色立方体示例Demo

1. 核心代码

我们已经讲解了足够多的内容，现在我们可以开始编写一个简单的颜色立方体演示程序了。这个例子基本上包含了我们前面讲到的所有内容。读者应该对照前面的几节，仔细研究这些代码，直到把每一行代码都弄懂为止。

//***************************************************************************************// BoxDemo.cpp by Frank Luna (C) 2011 All Rights Reserved.//// Demonstrates rendering a colored box.//// Controls://      Hold the left mouse button down and move the mouse to rotate.//      Hold the right mouse button down to zoom in and out.////***************************************************************************************#include "d3dApp.h"#include "d3dx11Effect.h"#include "MathHelper.h"struct Vertex{    XMFLOAT3 Pos;    XMFLOAT4 Color;};class BoxApp : public D3DApp{public:    BoxApp(HINSTANCE hInstance);    ~BoxApp();    bool Init();    void OnResize();    void UpdateScene(float dt);    void DrawScene();    void OnMouseDown(WPARAM btnState, int x, int y);    void OnMouseUp(WPARAM btnState, int x, int y);    void OnMouseMove(WPARAM btnState, int x, int y);private:    void BuildGeometryBuffers();    void BuildFX();    void BuildVertexLayout();private:    ID3D11Buffer* mBoxVB;    ID3D11Buffer* mBoxIB;    ID3DX11Effect* mFX;    ID3DX11EffectTechnique* mTech;    ID3DX11EffectMatrixVariable* mfxWorldViewProj;    ID3D11InputLayout* mInputLayout;    XMFLOAT4X4 mWorld;    XMFLOAT4X4 mView;    XMFLOAT4X4 mProj;    float mTheta;    float mPhi;    float mRadius;    POINT mLastMousePos;};int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE prevInstance,                   PSTR cmdLine, int showCmd){    // Enable run-time memory check for debug builds.#if defined(DEBUG) | defined(_DEBUG)    _CrtSetDbgFlag( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );#endif    BoxApp theApp(hInstance);    if( !theApp.Init() )        return 0;    return theApp.Run();}BoxApp::BoxApp(HINSTANCE hInstance): D3DApp(hInstance), mBoxVB(0), mBoxIB(0), mFX(0), mTech(0),  mfxWorldViewProj(0), mInputLayout(0),  mTheta(1.5f*MathHelper::Pi), mPhi(0.25f*MathHelper::Pi), mRadius(5.0f){    mMainWndCaption = L"Box Demo";    mLastMousePos.x = 0;    mLastMousePos.y = 0;    XMMATRIX I = XMMatrixIdentity();    XMStoreFloat4x4(&mWorld, I);    XMStoreFloat4x4(&mView, I);    XMStoreFloat4x4(&mProj, I);}BoxApp::~BoxApp(){    ReleaseCOM(mBoxVB);    ReleaseCOM(mBoxIB);    ReleaseCOM(mFX);    ReleaseCOM(mInputLayout);}bool BoxApp::Init(){    if(!D3DApp::Init())        return false;    BuildGeometryBuffers();    BuildFX();    BuildVertexLayout();    return true;}void BoxApp::OnResize(){    D3DApp::OnResize();    // 当窗口大小改变时，需要更新横纵比，并重新计算投影矩阵    XMMATRIX P = XMMatrixPerspectiveFovLH(0.25f*MathHelper::Pi, AspectRatio(), 1.0f, 1000.0f);    XMStoreFloat4x4(&mProj, P);}void BoxApp::UpdateScene(float dt){    // Convert Spherical to Cartesian coordinates.    float x = mRadius*sinf(mPhi)*cosf(mTheta);    float z = mRadius*sinf(mPhi)*sinf(mTheta);    float y = mRadius*cosf(mPhi);    // 创建视矩阵    XMVECTOR pos    = XMVectorSet(x, y, z, 1.0f);    XMVECTOR target = XMVectorZero();    XMVECTOR up     = XMVectorSet(0.0f, 1.0f, 0.0f, 0.0f);    XMMATRIX V = XMMatrixLookAtLH(pos, target, up);    XMStoreFloat4x4(&mView, V);}void BoxApp::DrawScene(){    md3dImmediateContext->ClearRenderTargetView(mRenderTargetView, reinterpret_cast
   
    (&Colors::LightSteelBlue));    md3dImmediateContext->ClearDepthStencilView(mDepthStencilView, D3D11_CLEAR_DEPTH|D3D11_CLEAR_STENCIL, 1.0f, 0);    md3dImmediateContext->IASetInputLayout(mInputLayout);    md3dImmediateContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);    UINT stride = sizeof(Vertex);    UINT offset = 0;    md3dImmediateContext->IASetVertexBuffers(0, 1, &mBoxVB, &stride, &offset);    md3dImmediateContext->IASetIndexBuffer(mBoxIB, DXGI_FORMAT_R32_UINT, 0);    // Set constants    XMMATRIX world = XMLoadFloat4x4(&mWorld);    XMMATRIX view  = XMLoadFloat4x4(&mView);    XMMATRIX proj  = XMLoadFloat4x4(&mProj);    XMMATRIX worldViewProj = world*view*proj;    mfxWorldViewProj->SetMatrix(reinterpret_cast
    
     (&worldViewProj));    D3DX11_TECHNIQUE_DESC techDesc;    mTech->GetDesc( &techDesc );    for(UINT p = 0; p < techDesc.Passes; ++p)    {        mTech->GetPassByIndex(p)->Apply(0, md3dImmediateContext);        // 立方体有36个索引        md3dImmediateContext->DrawIndexed(36, 0, 0);    }    HR(mSwapChain->Present(0, 0));}void BoxApp::OnMouseDown(WPARAM btnState, int x, int y){    mLastMousePos.x = x;    mLastMousePos.y = y;    SetCapture(mhMainWnd);}void BoxApp::OnMouseUp(WPARAM btnState, int x, int y){    ReleaseCapture();}void BoxApp::OnMouseMove(WPARAM btnState, int x, int y){    if( (btnState & MK_LBUTTON) != 0 )    {        // Make each pixel correspond to a quarter of a degree.        float dx = XMConvertToRadians(0.25f*static_cast
     
      (x - mLastMousePos.x));        float dy = XMConvertToRadians(0.25f*static_cast
      
       (y - mLastMousePos.y));        // Update angles based on input to orbit camera around box.        mTheta += dx;        mPhi   += dy;        // Restrict the angle mPhi.        mPhi = MathHelper::Clamp(mPhi, 0.1f, MathHelper::Pi-0.1f);    }    else if( (btnState & MK_RBUTTON) != 0 )    {        // Make each pixel correspond to 0.005 unit in the scene.        float dx = 0.005f*static_cast
       
        (x - mLastMousePos.x);        float dy = 0.005f*static_cast
        
         (y - mLastMousePos.y); // Update the camera radius based on input. mRadius += dx - dy; // Restrict the radius. mRadius = MathHelper::Clamp(mRadius, 3.0f, 15.0f); } mLastMousePos.x = x; mLastMousePos.y = y;}void BoxApp::BuildGeometryBuffers(){ // 创建顶点缓冲 Vertex vertices[] = { { XMFLOAT3(-1.0f, -1.0f, -1.0f), (const float*)&Colors::White }, { XMFLOAT3(-1.0f, +1.0f, -1.0f), (const float*)&Colors::Black }, { XMFLOAT3(+1.0f, +1.0f, -1.0f), (const float*)&Colors::Red }, { XMFLOAT3(+1.0f, -1.0f, -1.0f), (const float*)&Colors::Green }, { XMFLOAT3(-1.0f, -1.0f, +1.0f), (const float*)&Colors::Blue }, { XMFLOAT3(-1.0f, +1.0f, +1.0f), (const float*)&Colors::Yellow }, { XMFLOAT3(+1.0f, +1.0f, +1.0f), (const float*)&Colors::Cyan }, { XMFLOAT3(+1.0f, -1.0f, +1.0f), (const float*)&Colors::Magenta } }; D3D11_BUFFER_DESC vbd; vbd.Usage = D3D11_USAGE_IMMUTABLE; vbd.ByteWidth = sizeof(Vertex) * 8; vbd.BindFlags = D3D11_BIND_VERTEX_BUFFER; vbd.CPUAccessFlags = 0; vbd.MiscFlags = 0; vbd.StructureByteStride = 0; D3D11_SUBRESOURCE_DATA vinitData; vinitData.pSysMem = vertices; HR(md3dDevice->CreateBuffer(&vbd, &vinitData, &mBoxVB)); // 创建索引缓冲 UINT indices[] = { // 前表面 0, 1, 2, 0, 2, 3, // 后表面 4, 6, 5, 4, 7, 6, // 左表面 4, 5, 1, 4, 1, 0, // 右表面 3, 2, 6, 3, 6, 7, // 上表面 1, 5, 6, 1, 6, 2, // 下表面 4, 0, 3, 4, 3, 7 }; D3D11_BUFFER_DESC ibd; ibd.Usage = D3D11_USAGE_IMMUTABLE; ibd.ByteWidth = sizeof(UINT) * 36; ibd.BindFlags = D3D11_BIND_INDEX_BUFFER; ibd.CPUAccessFlags = 0; ibd.MiscFlags = 0; ibd.StructureByteStride = 0; D3D11_SUBRESOURCE_DATA iinitData; iinitData.pSysMem = indices; HR(md3dDevice->CreateBuffer(&ibd, &iinitData, &mBoxIB));}void BoxApp::BuildFX(){ DWORD shaderFlags = 0; #if defined( DEBUG ) || defined( _DEBUG ) shaderFlags |= D3D10_SHADER_DEBUG; shaderFlags |= D3D10_SHADER_SKIP_OPTIMIZATION; #endif ID3D10Blob* compiledShader = 0; ID3D10Blob* compilationMsgs = 0; HRESULT hr = D3DX11CompileFromFile(L"FX/color.fx", 0, 0, 0, "fx_5_0", shaderFlags, 0, 0, &compiledShader, &compilationMsgs, 0); // compilationMsgs中包含错误或警告信息 if( compilationMsgs != 0 ) { MessageBoxA(0, (char*)compilationMsgs->GetBufferPointer(), 0, 0); ReleaseCOM(compilationMsgs); } // 就算没有compilationMsgs，也需要确保没有其他错误 if(FAILED(hr)) { DXTrace(__FILE__, (DWORD)__LINE__, hr, L"D3DX11CompileFromFile", true); } HR(D3DX11CreateEffectFromMemory(compiledShader->GetBufferPointer(), compiledShader->GetBufferSize(), 0, md3dDevice, &mFX)); // 编译完成释放资源 ReleaseCOM(compiledShader); mTech = mFX->GetTechniqueByName("ColorTech"); mfxWorldViewProj = mFX->GetVariableByName("gWorldViewProj")->AsMatrix();}void BoxApp::BuildVertexLayout(){ // 顶点输入布局描述 D3D11_INPUT_ELEMENT_DESC vertexDesc[] = { { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0}, { "COLOR", 0, DXGI_FORMAT_R32G32B32A32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0} }; // 创建顶点输入布局 D3DX11_PASS_DESC passDesc; mTech->GetPassByIndex(0)->GetDesc(&passDesc); HR(md3dDevice->CreateInputLayout(vertexDesc, 2, passDesc.pIAInputSignature, passDesc.IAInputSignatureSize, &mInputLayout));}