Question

我有一个d3d9代理dll。

我需要将D3DXMATRIX保存在SetTransform函数中，以便在另一个函数中使用它。

我在

开头声明它们

D3DXMATRIX view_matrix, proj_matrix, world_matrix;

在SetTransform函数中

我有：

HRESULT my_IDirect3DDevice9::SetTransform(D3DTRANSFORMSTATETYPE State,CONST D3DMATRIX* pMatrix)
{
    if (State == D3DTS_VIEW)
    {
        &view_matrix = pMatrix;
    }
    if (State == D3DTS_PROJECTION)
    {
        &proj_matrix = pMatrix;
    }
    if (State == D3DTS_WORLD)
    {
        &world_matrix = pMatrix;
    }
    return(m_pIDirect3DDevice9->SetTransform(State,pMatrix));
}

编译器错误消息：

my_IDirect3DDevice9.cpp
my_IDirect3DDevice9.cpp(838) : error C2440: '=' : cannot convert from 'const D3DMATRIX *' to 'D3DXMATRIX *'
        Cast from base to derived requires dynamic_cast or static_cast
my_IDirect3DDevice9.cpp(842) : error C2440: '=' : cannot convert from 'const D3DMATRIX *' to 'D3DXMATRIX *'
        Cast from base to derived requires dynamic_cast or static_cast
my_IDirect3DDevice9.cpp(846) : error C2440: '=' : cannot convert from 'const D3DMATRIX *' to 'D3DXMATRIX *'
        Cast from base to derived requires dynamic_cast or static_cast
NMAKE : fatal error U1077: '"c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\cl.EXE"' : return code '0x2'

我稍后需要这3个矩阵进行计算：

m_pIDirect3DDevice9->GetTransform( D3DTS_VIEW, &view_matrix );
m_pIDirect3DDevice9->GetTransform( D3DTS_PROJECTION, &proj_matrix );
m_pIDirect3DDevice9->GetTransform( D3DTS_WORLD, &world_matrix );
m_pIDirect3DDevice9->GetViewport( &d3dvp );
D3DXVec3Project( &vector_2d, &vector_3d, &d3dvp, &proj_matrix, &view_matrix, &world_matrix );
D3DXVec3Unproject( &vector_3d, &vector_2d, &d3dvp, &proj_matrix, &view_matrix, &world_matrix );

因为GetTransform在Windows XP系统上失败了。所以我需要在他们设置好之后才能获得它们。

Answer 1

＆amp; view_matrix是view_matrix的地址，它是一个r值，你不能分配给r值。

试试这个：

if (State == D3DTS_VIEW)
{
    view_matrix = *pMatrix;
}
if (State == D3DTS_PROJECTION)
{
    proj_matrix = *pMatrix;
}
if (State == D3DTS_WORLD)
{
    world_matrix = *pMatrix;
}

D3D9代理DLL存储D3DXMATRIX（c ++）

1 个答案: