Gets a pointer to an array of constant descriptions in the constant table.
HRESULT GetConstantDesc( D3DXHANDLE hConstant, D3DXCONSTANT_DESC * pDesc, UINT * pCount );
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be one of the following: D3DERR_INVALIDCALL, D3DXERR_INVALIDDATA.
ID3DXConstantTable::GetConstantDesc will sometimes return a D3DXCONSTANT_DESC with a Register_Count of 0. This will happen with a constant appears in more than one Register_Set but does not have space in that register set allocated.
Because a sampler can appear more than once in a constant table, this method can return an array of descriptions, each one with a different register index.
Header: Declared in D3dx9shader.h.