类CDXUTMeshFile位于DXUTMesh.h和DXUTMesh.cpp中，继承自类CDXUTMeshFrame，其实类CDXUTMeshFrame本身只完成一些基础操作，不是最终使用的一个类，CDXUTMeshFile在CDXUTMeshFrame的基础上将各种操作进一步封装。
在.x网格模型中使用框架的主要目的是实现模型自身包含的动画，而CDXUTMeshFile和CDXUTMeshFrame虽然考虑了网格模型的层次框架，可是并没有实现对网格模型动画的播放，所以通常不直接使用这两个类，因为对于不包含动画信息的静态网格模型CDXUTMesh类就已经足够了。当然也完全可以像使用CDXUTMesh类一样使用CDXUTMeshFile类来操作不包含动画信息的网格模型。
来看看CDXUTMeshFile的定义：
//-----------------------------------------------------------------------------
// Name: class CDXUTMeshFile
// Desc: Class for loading and rendering file-based meshes
//-----------------------------------------------------------------------------
class CDXUTMeshFile : public CDXUTMeshFrame
{
HRESULT LoadMesh( LPDIRECT3DDEVICE9 pd3dDevice, LPD3DXFILEDATA pFileData, CDXUTMeshFrame* pParentFrame );
HRESULT LoadFrame( LPDIRECT3DDEVICE9 pd3dDevice, LPD3DXFILEDATA pFileData, CDXUTMeshFrame* pParentFrame );
public:
HRESULT Create( LPDIRECT3DDEVICE9 pd3dDevice, LPCWSTR strFilename );
HRESULT CreateFromResource( LPDIRECT3DDEVICE9 pd3dDevice, LPCWSTR strResource, LPCWSTR strType );
// For pure devices, specify the world transform.
// If the world transform is not specified on pure devices, this function will fail.
HRESULT Render( LPDIRECT3DDEVICE9 pd3dDevice, D3DXMATRIX* pmatWorldMatrix = NULL );
CDXUTMeshFile() : CDXUTMeshFrame( L"CDXUTMeshFile_Root" ) {}
};
LoadMesh()负责从ID3DXFileData中加载一个网格，该函数是内部调用的，其实质是调用CDXUTMesh::Create()函数来加载。
HRESULT CDXUTMeshFile::LoadMesh(LPDIRECT3DDEVICE9 pd3dDevice, LPD3DXFILEDATA pFileData, CDXUTMeshFrame* pParentFrame)
{
// Currently only allowing one mesh per frame
if( pParentFrame->m_pMesh )
return E_FAIL;
// Get the mesh name
CHAR strAnsiName[512] = {0};
WCHAR strName[512];
SIZE_T dwNameLength = 512;
HRESULT hr;
if( FAILED( hr = pFileData->GetName(strAnsiName, &dwNameLength) ) )
return hr;
MultiByteToWideChar(CP_ACP, 0, strAnsiName, -1, strName, 512);
strName[511] = 0;
// Create the mesh
pParentFrame->m_pMesh = new CDXUTMesh(strName);
if( pParentFrame->m_pMesh == NULL )
return E_OUTOFMEMORY;
pParentFrame->m_pMesh->Create( pd3dDevice, pFileData );
return S_OK;
}
LoadFrame()用于从ID3DXFileData中加载一个框架：
HRESULT CDXUTMeshFile::LoadFrame(LPDIRECT3DDEVICE9 pd3dDevice, LPD3DXFILEDATA pFileData, CDXUTMeshFrame* pParentFrame)
{
LPD3DXFILEDATA pChildData = NULL;
GUID Guid;
SIZE_T cbSize;
CDXUTMeshFrame* pCurrentFrame;
HRESULT hr;
// Get the type of the object
if( FAILED( hr = pFileData->GetType( &Guid ) ) )
return hr;
if(Guid == TID_D3DRMMesh)
{
hr = LoadMesh(pd3dDevice, pFileData, pParentFrame);
if( FAILED(hr) )
return hr;
}
if(Guid == TID_D3DRMFrameTransformMatrix)
{
D3DXMATRIX* pmatMatrix;
hr = pFileData->Lock(&cbSize, (LPCVOID*) &pmatMatrix);
if( FAILED(hr) )
return hr;
// Update the parent's matrix with the new one
pParentFrame->SetMatrix(pmatMatrix);
}
if(Guid == TID_D3DRMFrame)
{
// Get the frame name
CHAR strAnsiName[512] = "";
WCHAR strName[512];
SIZE_T dwNameLength = 512;
SIZE_T cChildren;
if( FAILED( hr = pFileData->GetName(strAnsiName, &dwNameLength) ) )
return hr;
MultiByteToWideChar(CP_ACP, 0, strAnsiName, -1, strName, 512);
strName[511] = 0;
// Create the frame
pCurrentFrame = new CDXUTMeshFrame(strName);
if(pCurrentFrame == NULL)
return E_OUTOFMEMORY;
pCurrentFrame->m_pNext = pParentFrame->m_pChild;
pParentFrame->m_pChild = pCurrentFrame;
// Enumerate child objects
pFileData->GetChildren(&cChildren);
for (UINT iChild = 0; iChild < cChildren; iChild++)
{
// Query the child for its FileData
hr = pFileData->GetChild(iChild, &pChildData);
if( SUCCEEDED(hr) )
{
hr = LoadFrame(pd3dDevice, pChildData, pCurrentFrame);
SAFE_RELEASE( pChildData );
}
if( FAILED(hr) )
return hr;
}
}
return S_OK;
}
首先，该函数调用GetType()获取对象的GUID：
// Get the type of the object if( FAILED( hr = pFileData->GetType( &Guid ) ) ) return hr;
接下来根据GUID分别进行相应的操作，若是网格则调用LoadMesh()加载网格，若是框架变换矩阵则设置变换矩阵，若是框架，相应的操作有些复杂，首先获取框架的名称并将其转化为widechar类型：
if( FAILED( hr = pFileData->GetName(strAnsiName, &dwNameLength) ) ) return hr;
MultiByteToWideChar(CP_ACP, 0, strAnsiName, -1, strName, 512); strName[511] = 0;
接着新建一个CDXUTMeshFrame对象并将其添加进链表：
// Create the frame pCurrentFrame = new CDXUTMeshFrame(strName); if(pCurrentFrame == NULL) return E_OUTOFMEMORY;
pCurrentFrame->m_pNext = pParentFrame->m_pChild; pParentFrame->m_pChild = pCurrentFrame;
最后遍历子框架并递归调用LoadFrame()加载框架:
// Enumerate child objects
pFileData->GetChildren(&cChildren);
for (UINT iChild = 0; iChild < cChildren; iChild++) { // Query the child for its FileData hr = pFileData->GetChild(iChild, &pChildData);
if( SUCCEEDED(hr) ) { hr = LoadFrame(pd3dDevice, pChildData, pCurrentFrame); SAFE_RELEASE( pChildData ); }
if( FAILED(hr) ) return hr; }
第一个Create()函数负责从模型文件加载网格模型：
HRESULT CDXUTMeshFile::Create(LPDIRECT3DDEVICE9 pd3dDevice, LPCWSTR strFilename)
{
LPD3DXFILE pDXFile = NULL;
LPD3DXFILEENUMOBJECT pEnumObj = NULL;
LPD3DXFILEDATA pFileData = NULL;
HRESULT hr;
SIZE_T cChildren;
// Create a x file object
if( FAILED( hr = D3DXFileCreate(&pDXFile) ) )
return E_FAIL;
// Register templates for d3drm and patch extensions.
if( FAILED( hr = pDXFile->RegisterTemplates((void*) D3DRM_XTEMPLATES, D3DRM_XTEMPLATE_BYTES) ) )
{
SAFE_RELEASE( pDXFile );
return E_FAIL;
}
// Find the path to the file, and convert it to ANSI (for the D3DXOF API)
WCHAR strPath[MAX_PATH];
CHAR strPathANSI[MAX_PATH];
DXUTFindDXSDKMediaFileCch(strPath, sizeof(strPath) / sizeof(WCHAR), strFilename);
WideCharToMultiByte(CP_ACP, 0, strPath, -1, strPathANSI, MAX_PATH, NULL, NULL);
strPathANSI[MAX_PATH - 1] = 0;
// Create enum object
hr = pDXFile->CreateEnumObject((void*) strPathANSI, D3DXF_FILELOAD_FROMFILE, &pEnumObj);
if( FAILED(hr) )
{
SAFE_RELEASE( pDXFile );
return hr;
}
// Enumerate top level objects (which are always frames)
pEnumObj->GetChildren(&cChildren);
for (UINT iChild = 0; iChild < cChildren; iChild++)
{
hr = pEnumObj->GetChild(iChild, &pFileData);
if (FAILED(hr))
return hr;
hr = LoadFrame(pd3dDevice, pFileData, this);
SAFE_RELEASE(pFileData);
if( FAILED(hr) )
{
SAFE_RELEASE(pEnumObj);
SAFE_RELEASE(pDXFile);
return E_FAIL;
}
}
SAFE_RELEASE(pFileData);
SAFE_RELEASE(pEnumObj);
SAFE_RELEASE(pDXFile);
return S_OK;
}
首先函数创建了一个ID3DXFileData对象并注册了XFILE标准模板：
// Create a x file object if( FAILED( hr = D3DXFileCreate(&pDXFile) ) ) return E_FAIL;
// Register templates for d3drm and patch extensions. if( FAILED( hr = pDXFile->RegisterTemplates((void*) D3DRM_XTEMPLATES, D3DRM_XTEMPLATE_BYTES) ) ) { SAFE_RELEASE( pDXFile ); return E_FAIL; }
接下来查找网格模型文件将路径存储在strPath中，并将该路径转化为ANSI类型存储在strPathANSI中：
// Find the path to the file, and convert it to ANSI (for the D3DXOF API)
WCHAR strPath[MAX_PATH]; CHAR strPathANSI[MAX_PATH]; DXUTFindDXSDKMediaFileCch(strPath, sizeof(strPath) / sizeof(WCHAR), strFilename);
WideCharToMultiByte(CP_ACP, 0, strPath, -1, strPathANSI, MAX_PATH, NULL, NULL); strPathANSI[MAX_PATH - 1] = 0;
再接下来创建一个ID3DXFileEnumObject枚举对象负责从.x文件中读取数据：
// Create enum object hr = pDXFile->CreateEnumObject((void*) strPathANSI, D3DXF_FILELOAD_FROMFILE, &pEnumObj);
if( FAILED(hr) ) { SAFE_RELEASE( pDXFile ); return hr; }
函数CreateEnumObject()声明如下：
Creates an enumerator object that will read a .x file.
HRESULT CreateEnumObject( LPCVOID pvSource, D3DXF_FILELOADOPTIONS loadflags, ID3DXFileEnumObject ** ppEnumObj);
Parameters
pvSource
[out] The data source. Either:
A file name
A D3DXF_FILELOADMEMORY structure
A D3DXF_FILELOADRESOURCE structure
Depending on the value of loadflags.
loadflags
[in] Value that specifies the source of the data. This value can be one of the D3DXF_FILELOADOPTIONS flags.
ppEnumObj
[out] Address of a pointer to an ID3DXFileEnumObject interface, representing the created enumerator object.
Return Values
If the method succeeds, the return value is S_OK. If the method fails, the return value can be one of the following: D3DXFERR_BADVALUE, D3DXFERR_PARSEERROR.
Remarks
After using this method, use one of the ID3DXFileEnumObject methods to retrieve a data object.
再接下来通过ID3DXFileEnumObjec枚举对象读取数据并调用LoadFrame()加载框架：
// Enumerate top level objects (which are always frames) pEnumObj->GetChildren(&cChildren);
for (UINT iChild = 0; iChild < cChildren; iChild++) { hr = pEnumObj->GetChild(iChild, &pFileData); if (FAILED(hr)) return hr;
hr = LoadFrame(pd3dDevice, pFileData, this); SAFE_RELEASE(pFileData);
if( FAILED(hr) ) { SAFE_RELEASE(pEnumObj); SAFE_RELEASE(pDXFile); return E_FAIL; } }
最后释放不再使用的COM对象：
SAFE_RELEASE(pFileData); SAFE_RELEASE(pEnumObj); SAFE_RELEASE(pDXFile);
第二个Create()函数与第一个非常类似，只是该函数负责从资源加载网格模型：
HRESULT CDXUTMeshFile::CreateFromResource(LPDIRECT3DDEVICE9 pd3dDevice, LPCWSTR strResource, LPCWSTR strType)
{
LPD3DXFILE pDXFile = NULL;
LPD3DXFILEENUMOBJECT pEnumObj = NULL;
LPD3DXFILEDATA pFileData = NULL;
HRESULT hr;
SIZE_T cChildren;
// Create a x file object
if( FAILED( hr = D3DXFileCreate(&pDXFile) ) )
return E_FAIL;
// Register templates for d3drm and patch extensions.
if( FAILED( hr = pDXFile->RegisterTemplates((void*) D3DRM_XTEMPLATES, D3DRM_XTEMPLATE_BYTES) ) )
{
SAFE_RELEASE( pDXFile );
return E_FAIL;
}
CHAR strTypeAnsi[MAX_PATH];
CHAR strResourceAnsi[MAX_PATH];
WideCharToMultiByte(CP_ACP, 0, strType, -1, strTypeAnsi, MAX_PATH, NULL, NULL);
strTypeAnsi[MAX_PATH - 1] = 0;
WideCharToMultiByte(CP_ACP, 0, strResource, -1, strResourceAnsi, MAX_PATH, NULL, NULL);
strResourceAnsi[MAX_PATH - 1] = 0;
D3DXF_FILELOADRESOURCE dxlr;
dxlr.hModule = NULL;
dxlr.lpName = strResourceAnsi;
dxlr.lpType = strTypeAnsi;
// Create enum object
hr = pDXFile->CreateEnumObject((void*) &dxlr, D3DXF_FILELOAD_FROMRESOURCE, &pEnumObj);
if( FAILED(hr) )
{
SAFE_RELEASE( pDXFile );
return hr;
}
// Enumerate top level objects (which are always frames)
pEnumObj->GetChildren(&cChildren);
for (UINT iChild = 0; iChild < cChildren; iChild++)
{
hr = pEnumObj->GetChild(iChild, &pFileData);
if (FAILED(hr))
return hr;
hr = LoadFrame(pd3dDevice, pFileData, this);
SAFE_RELEASE( pFileData );
if( FAILED(hr) )
{
SAFE_RELEASE(pEnumObj);
SAFE_RELEASE(pDXFile);
return E_FAIL;
}
}
SAFE_RELEASE(pFileData);
SAFE_RELEASE(pEnumObj);
SAFE_RELEASE(pDXFile);
return S_OK;
}
唯一需要解释的代码是：
D3DXF_FILELOADRESOURCE dxlr;
dxlr.hModule = NULL; dxlr.lpName = strResourceAnsi; dxlr.lpType = strTypeAnsi;
// Create enum object hr = pDXFile->CreateEnumObject((void*) &dxlr, D3DXF_FILELOAD_FROMRESOURCE, &pEnumObj);
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计算机技术与应用 → 『 C/C++编程思想 』 → DXUT源码分析 ---- 类CDXUTMeshFile
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2008/12/26 10:52:00
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DXUT源码分析 ---- 类CDXUTMeshFile(12886字) － 卷积内核，2008年12月26日
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