類CDXUTMeshFrame封裝了CDXUTMesh，與CDXUTMesh不同的是，類CDXUTMeshFrame可以包含框架層次結(jié)構(gòu)，適用于更復(fù)雜的網(wǎng)格模型，框架層次正是骨骼動(dòng)畫所必須的。
首先來(lái)看看它的定義：
//-----------------------------------------------------------------------------
// Name: class CDXUTMeshFrame
// Desc: Class for loading and rendering file-based meshes
//-----------------------------------------------------------------------------
class CDXUTMeshFrame
{
public:
WCHAR m_strName[512]; // 框架名稱
D3DXMATRIX m_mat; // 框架變換矩陣（相對(duì)于網(wǎng)格模型的原點(diǎn)）
CDXUTMesh* m_pMesh; // 指向CDXUTMesh對(duì)象
CDXUTMeshFrame* m_pNext; // 指向下一個(gè)框架對(duì)象
CDXUTMeshFrame* m_pChild; // 指向子框架對(duì)象
public:
// Matrix access
void SetMatrix( D3DXMATRIX* pmat ) { m_mat = *pmat; }
D3DXMATRIX* GetMatrix() { return &m_mat; }
CDXUTMesh* FindMesh( LPCWSTR strMeshName );
CDXUTMeshFrame* FindFrame( LPCWSTR strFrameName );
bool EnumMeshes( bool (*EnumMeshCB)(CDXUTMesh*, void*), void* pContext );
HRESULT Destroy();
HRESULT RestoreDeviceObjects(LPDIRECT3DDEVICE9 pd3dDevice);
HRESULT InvalidateDeviceObjects();
HRESULT Render( LPDIRECT3DDEVICE9 pd3dDevice,
bool bDrawOpaqueSubsets = true,
bool bDrawAlphaSubsets = true,
D3DXMATRIX* pmatWorldMatrix = NULL);
CDXUTMeshFrame( LPCWSTR strName = L"CDXUTMeshFile_Frame" );
virtual ~CDXUTMeshFrame();
};
構(gòu)造函數(shù)和析構(gòu)函數(shù)只是負(fù)責(zé)初始化數(shù)據(jù)和釋放分配的資源：
CDXUTMeshFrame::CDXUTMeshFrame( LPCWSTR strName )
{
StringCchCopy(m_strName, 512, strName);
D3DXMatrixIdentity(&m_mat);
m_pMesh = NULL;
m_pChild = NULL;
m_pNext = NULL;
}
CDXUTMeshFrame::~CDXUTMeshFrame()
{
SAFE_DELETE( m_pChild );
SAFE_DELETE( m_pNext );
}
FindMesh()和FindFrame()是兩個(gè)遞歸查找函數(shù)，根據(jù)輸入的網(wǎng)格名稱和框架名稱查找對(duì)應(yīng)的網(wǎng)格和框架：
CDXUTMesh* CDXUTMeshFrame::FindMesh( LPCWSTR strMeshName )
{
CDXUTMesh* pMesh;
if( m_pMesh )
if( !lstrcmpi(m_pMesh->m_strName, strMeshName) )
return m_pMesh;
if( m_pChild )
if( NULL != ( pMesh = m_pChild->FindMesh(strMeshName) ) )
return pMesh;
if( m_pNext )
if( NULL != ( pMesh = m_pNext->FindMesh(strMeshName) ) )
return pMesh;
return NULL;
}
CDXUTMeshFrame* CDXUTMeshFrame::FindFrame( LPCWSTR strFrameName )
{
CDXUTMeshFrame* pFrame;
if( !lstrcmpi(m_strName, strFrameName) )
return this;
if( m_pChild )
if( NULL != ( pFrame = m_pChild->FindFrame(strFrameName) ) )
return pFrame;
if( m_pNext )
if( NULL != ( pFrame = m_pNext->FindFrame(strFrameName) ) )
return pFrame;
return NULL;
}
lstrcmpi()在比較兩個(gè)字符串時(shí)忽略大小寫：
The lstrcmpi function compares two character
strings. The comparison is not case sensitive.
To perform a comparison that is case sensitive, use
the lstrcmp function.
Syntax
int lstrcmpi(
LPCTSTR lpString1,
LPCTSTR lpString2
);
Parameters
- lpString1
- [in] Pointer to the first null-terminated
string to be compared.
- lpString2
- [in] Pointer to the second null-terminated
string to be compared.
Return Value
If the string pointed to by lpString1 is
less than the string pointed to by lpString2, the return value is
negative. If the string pointed to by lpString1 is greater than
the string pointed to by lpString2, the return value is positive.
If the strings are equal, the return value is zero.
Remarks
The lstrcmpi function compares two
strings by checking the first characters against each other, the second
characters against each other, and so on until it finds an inequality or
reaches the ends of the strings.
Note that the lpString1 and lpString2
parameters must be null terminated, otherwise the string comparison can
be incorrect.
The function returns the difference of the
values of the first unequal characters it encounters. For example,
lstrcmpi determines that "abcz" is greater than "abcdefg" and
returns the difference of z and d.
The language (user locale) selected by the user
at setup time, or through Control Panel, determines which string is
greater (or whether the strings are the same). If no language (user
locale) is selected, the system performs the comparison by using default
values.
For some locales, the lstrcmpi function
may be insufficient. If this occurs, use CompareString to ensure proper
comparison. For example, in Japan call with the
NORM_IGNORECASE, NORM_IGNOREKANATYPE,
and NORM_IGNOREWIDTH values to achieve the
most appropriate non-exact string comparison. The
NORM_IGNOREKANATYPE and NORM_IGNOREWIDTH
values are ignored in non-Asian locales, so you can set these values for
all locales and be guaranteed to have a culturally correct "insensitive"
sorting regardless of the locale. Note that specifying these values
slows performance, so use them only when necessary.
With a double-byte character set (DBCS) version
of the system, this function can compare two DBCS strings.
The lstrcmpi function uses a word sort,
rather than a string sort. A word sort treats hyphens and apostrophes
differently than it treats other symbols that are not alphanumeric, in
order to ensure that words such as "coop" and "co-op" stay together
within a sorted list. For a detailed discussion of word sorts and string
sorts, see the Remarks section for the CompareString function.
EnumMeshes()是一個(gè)遞歸枚舉函數(shù)，對(duì)所有框架的所有網(wǎng)格遞歸調(diào)用傳遞進(jìn)來(lái)的函數(shù)：
bool CDXUTMeshFrame::EnumMeshes( bool (*EnumMeshCB)(CDXUTMesh*, void*), void* pContext )
{
if( m_pMesh )
EnumMeshCB( m_pMesh, pContext );
if( m_pChild )
m_pChild->EnumMeshes( EnumMeshCB, pContext );
if( m_pNext )
m_pNext->EnumMeshes( EnumMeshCB, pContext );
return TRUE;
}
Destroy()、RestoreDeviceObjects()、InvalidateDeviceObjects()分別當(dāng)摧毀網(wǎng)格框架、設(shè)備恢復(fù)、設(shè)備丟失時(shí)調(diào)用，需要注意的是該類的析構(gòu)函數(shù)并沒(méi)有釋放分配的資源，只是刪除了鏈表指針，必須顯式調(diào)用Destroy()來(lái)釋放資源：
HRESULT CDXUTMeshFrame::Destroy()
{
if( m_pMesh ) m_pMesh->Destroy();
if( m_pChild ) m_pChild->Destroy();
if( m_pNext ) m_pNext->Destroy();
SAFE_DELETE( m_pMesh );
SAFE_DELETE( m_pNext );
SAFE_DELETE( m_pChild );
return S_OK;
}
HRESULT CDXUTMeshFrame::RestoreDeviceObjects( LPDIRECT3DDEVICE9 pd3dDevice )
{
if( m_pMesh ) m_pMesh->RestoreDeviceObjects( pd3dDevice );
if( m_pChild ) m_pChild->RestoreDeviceObjects( pd3dDevice );
if( m_pNext ) m_pNext->RestoreDeviceObjects( pd3dDevice );
return S_OK;
}
HRESULT CDXUTMeshFrame::InvalidateDeviceObjects()
{
if( m_pMesh ) m_pMesh->InvalidateDeviceObjects();
if( m_pChild ) m_pChild->InvalidateDeviceObjects();
if( m_pNext ) m_pNext->InvalidateDeviceObjects();
return S_OK;
}
Render()負(fù)責(zé)網(wǎng)格框架的繪制，它只是調(diào)用CDXUTMesh::Render()來(lái)負(fù)責(zé)網(wǎng)格的繪制，由于框架的層次包含關(guān)系，所以該函數(shù)也是一個(gè)遞歸函數(shù)。需要注意的是該函數(shù)包含的最后一個(gè)參數(shù)，它允許用戶指定世界坐標(biāo)變換矩陣，如果該參數(shù)為NULL，則從設(shè)備獲取已設(shè)置好的世界坐標(biāo)矩陣，注意如果是虛擬設(shè)備，必須設(shè)置該矩陣，不能為NULL。
HRESULT CDXUTMeshFrame::Render( LPDIRECT3DDEVICE9 pd3dDevice,
bool bDrawOpaqueSubsets, bool bDrawAlphaSubsets,
D3DXMATRIX* pmatWorldMatrix )
{
// For pure devices, specify the world transform.
// If the world transform is not specified on pure devices, this function will fail.
D3DXMATRIX matSavedWorld, matWorld;
if (NULL == pmatWorldMatrix)
pd3dDevice->GetTransform(D3DTS_WORLD, &matSavedWorld);
else
matSavedWorld = *pmatWorldMatrix;
D3DXMatrixMultiply(&matWorld, &m_mat, &matSavedWorld);
pd3dDevice->SetTransform(D3DTS_WORLD, &matWorld);
if( m_pMesh )
m_pMesh->Render(pd3dDevice, bDrawOpaqueSubsets, bDrawAlphaSubsets);
if( m_pChild )
m_pChild->Render(pd3dDevice, bDrawOpaqueSubsets, bDrawAlphaSubsets, &matWorld);
pd3dDevice->SetTransform(D3DTS_WORLD, &matSavedWorld);
if( m_pNext )
m_pNext->Render( pd3dDevice, bDrawOpaqueSubsets, bDrawAlphaSubsets, &matSavedWorld );
return S_OK;
}
代碼中需要注意的一點(diǎn)是，調(diào)用Render()繪制兄弟框架時(shí)傳遞的世界坐標(biāo)矩陣是matSavedWorld，而繪制子框架時(shí)傳遞的世界坐標(biāo)矩陣是matWorld。