渐进网格技术实现-优快云博客

本文链接：https://blog.youkuaiyun.com/lingang_/article/details/3105092
以先前文章中的 DirectX 框架为基础,写了一个导入.x文件生成渐进网格的例子。按下'A'键增加网格顶点数(不超过最大值) 按下 'S' 键减小顶点数 (不小于最小值)
代码清单:
 
 // 
//xfile.cpp  
//by tianzhihen 
//2008.10.19 
//VC8.0           
// 
#include "d3dUtility.h" 
#include <vector> 
IDirect3DDevice9* Device = 0 ;
const int Width = 640;
const int Height = 480;
ID3DXMesh*                      SourceMesh = 0; //网格 
ID3DXPMesh*                     PMesh = 0;      //渐进网格 
std::vector<D3DMATERIAL9>       Mtrl(0);        //材质 
std::vector<IDirect3DTexture9*> Textures(0);    //纹理 
bool Setup()
{
    HRESULT hr = 0;
    ID3DXBuffer* adjBuffer = 0;   // 邻接缓存 
    ID3DXBuffer* mtrlBuffer = 0;  // 材质缓存 
    DWORD numMtrls = 0;           // 材质数量 
    // 
    // 从 .X 文件中加载数据到网格 
    // 
    hr = D3DXLoadMeshFromX(
        "bigship1.x",
        D3DXMESH_MANAGED,//托管内存池 
        Device,
        &adjBuffer,
        &mtrlBuffer,
        0,
        &numMtrls,
        &SourceMesh //目的网格地址 
        );
    if(FAILED(hr))
    {
        ::MessageBox(0, "D3DXLoadMeshFromX() - FAILED", 0, 0);
        return false;
    }
    if (mtrlBuffer!=0&&numMtrls!=0)
    {
        //材质存在 
        /*
         typedef struct D3DXMATERIAL {
                D3DMATERIAL9 MatD3D;    //材质
                LPSTR pTextureFilename; //纹理地址
            } D3DXMATERIAL, *LPD3DXMATERIAL;
        */
        D3DXMATERIAL* mtrls =(D3DXMATERIAL*)mtrlBuffer->GetBufferPointer();
        for (int i=0;i<numMtrls;i++)
        {
            mtrls[i].MatD3D.Ambient = mtrls[i].MatD3D.Diffuse;  // .X 文件中没有定义材质的环境光分量 
            Mtrl.push_back(mtrls[i].MatD3D);
            if (mtrls[i].pTextureFilename!=0)
            {
                IDirect3DTexture9* tex = 0;
                D3DXCreateTextureFromFile(Device,mtrls[i].pTextureFilename,&tex);   //加载纹理 
                Textures.push_back(tex);
            }
            else
            {
                Textures.push_back(0);
            }
        }
    }
    d3d::Release<ID3DXBuffer*>(mtrlBuffer);
    // 
    // 优化网格数据 
    // 
    hr = SourceMesh->OptimizeInplace(
            D3DXMESHOPT_ATTRSORT|
            D3DXMESHOPT_COMPACT|
            D3DXMESHOPT_VERTEXCACHE,
            (DWORD*)adjBuffer->GetBufferPointer(),
            (DWORD*)adjBuffer->GetBufferPointer(),
            0,0
        );
    if (FAILED(hr))
    {
        ::MessageBox(0,"OptimizeInplace() - FAILED",0,0);
        d3d::Release<ID3DXBuffer*>(adjBuffer);
        return E_FAIL;
    }
    // 
    // 生成渐进网格 
    // 
    hr = D3DXGeneratePMesh(
            SourceMesh,
            (DWORD*)adjBuffer->GetBufferPointer(),
            0,
            0,
            1,
            D3DXMESHSIMP_FACE,
            
        );
    d3d::Release<ID3DXMesh*>(SourceMesh);
    d3d::Release<ID3DXBuffer*>(adjBuffer);
    if(FAILED(hr))
    {
        ::MessageBox(0, "D3DXGeneratePMesh() - FAILED", 0, 0);
        return E_FAIL;
    }
    // 设置渐进网格初始面片值为最大 
    DWORD maxFaces = PMesh->GetMaxFaces();
    PMesh->SetNumFaces(maxFaces);
    //纹理采样模式 
    Device->SetSamplerState(0, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);
    Device->SetSamplerState(0, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);
    Device->SetSamplerState(0, D3DSAMP_MIPFILTER, D3DTEXF_POINT);
    // 
    // 设置光照 
    // 
    D3DXVECTOR3 dir(1.0f,-1.0f,1.0f);
    D3DXCOLOR col(1.0f,1.0f,1.0f,1.0f);
    D3DLIGHT9 light = d3d::InitDirectionalLight(&dir,&col);
    Device->SetLight(0,&light);
    Device->LightEnable(0,true);
    Device->SetRenderState(D3DRS_NORMALIZENORMALS, true);
    Device->SetRenderState(D3DRS_SPECULARENABLE, true);
    // 
    // 设置取景变换矩阵 
    // 
    D3DXVECTOR3 pos(-8.0f, 4.0f, -12.0f);
    D3DXVECTOR3 target(0.0f, 0.0f, 0.0f);
    D3DXVECTOR3 up(0.0f, 1.0f, 0.0f);
    D3DXMATRIX V;
    D3DXMatrixLookAtLH(
        &V,
        &pos,
        &target,
        &up);
    Device->SetTransform(D3DTS_VIEW, &V);
    // 
    // 设置投影矩阵 
    // 
    D3DXMATRIX proj;
    D3DXMatrixPerspectiveFovLH(
        &proj,
        D3DX_PI * 0.5f, // 90 - degree 
        (float)Width / (float)Height,
        1.0f,
        1000.0f);
    Device->SetTransform(D3DTS_PROJECTION, &proj);
    return true;
}
void Cleanup()
{
    d3d::Release<ID3DXPMesh*>(PMesh);
    for (int i=0;i<Textures.size();i++)
    {
        d3d::Release<IDirect3DTexture9*>(Textures[i]);
    }
}
bool Display(float timeDelta)
{
    if (Device)
    {
        int numFaces = PMesh->GetNumFaces();
        if (::GetAsyncKeyState('A')&0x8000f)
        {
            //按下'A'键则增加面片数 
            PMesh->SetNumFaces(numFaces+1);
            if(PMesh->GetNumFaces()==numFaces)
                PMesh->SetNumFaces(numFaces+2);
        }
        if(::GetAsyncKeyState('S')&0x8000f)
        {
            //按下'S'键则减少面片数 
            PMesh->SetNumFaces(numFaces-1);
        }
        // 
        // 绘制场景 
        // 
        Device->Clear(0,0,D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER,0xffffffff,1.0f,0);
        Device->BeginScene();
        for (int i=0;i<Mtrl.size();i++)
        {
            //绘制模型 
            Device->SetMaterial(&Mtrl[i]);
            Device->SetTexture(0,Textures[i]);
            PMesh->DrawSubset(i);
            // 绘制面片线框 
            Device->SetMaterial(&d3d::YELLOW_MTRL);
            Device->SetRenderState(D3DRS_FILLMODE,D3DFILL_WIREFRAME);
            PMesh->DrawSubset(i);
            Device->SetRenderState(D3DRS_FILLMODE,D3DFILL_SOLID);
        }
        Device->EndScene();
        Device->Present(0,0,0,0);
        
    }
    return true;
}
// 
// WndProc 
// 
LRESULT CALLBACK d3d::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch( msg )
    {
    case WM_DESTROY:
        ::PostQuitMessage(0);
        break;
    case WM_KEYDOWN:
        if( wParam == VK_ESCAPE )
            ::DestroyWindow(hwnd);
        break;
    }
    return ::DefWindowProc(hwnd, msg, wParam, lParam);
}
// 
// WinMain 
// 
int WINAPI WinMain(HINSTANCE hinstance,
                   HINSTANCE prevInstance, 
                   PSTR cmdLine,
                   int showCmd)
{
    if(!d3d::InitD3D(hinstance,
        Width, Height, true, D3DDEVTYPE_HAL, &Device))
    {
        ::MessageBox(0, "InitD3D() - FAILED", 0, 0);
        return 0;
    }
    if(!Setup())
    {
        ::MessageBox(0, "Setup() - FAILED", 0, 0);
        return 0;
    }
    d3d::EnterMsgLoop( Display );
    Cleanup();
    Device->Release();
    return 0;
}
 