Question

Im having some probolems with C++ .. I’m trying to save a frame with the filename as timestamp but with no success, can anybody help me?

It saves properly if i use:

D3DXSaveTextureToFileW((LPCWSTR)"file.bmp",D3DXIFF_BMP,tex,NULL); or

D3DXSaveTextureToFileW(L"file.bmp", frameName,D3DXIFF_BMP,tex,NULL); 

But if I try some more elaborated filename I get some issues, it compiles but doesn’t save the file …

I’m trying to use someting like

LPCWSTR frameName;
std::string s = std::string("file") + std::string(".bmp");
frameName = (LPCWSTR)s.c_str();
D3DXSaveTextureToFileW((LPCWSTR)frameName,D3DXIFF_BMP,tex,NULL);

Doesn’t save … And If I try something like I want to save the problem continues:

time_t seconds;
seconds = time (NULL);      
time_t rawtime;
time ( &rawtime );

LPCWSTR frameName;
std::string s = std::string("file") + std::string(&rawtime);
frameName = (LPCWSTR)s.c_str();

D3DXSaveTextureToFileW((LPCWSTR)frameName,D3DXIFF_BMP,tex,NULL);

Answer 1

You cannot cast the result of std::string::c_str() (a const char*) to a LPCWSTR. Use a std::wstringstream to construct the filename:

#include <sstream>
...
std::wstringstream frameName;
frameName << L"file" << rawtime << L".bmp";
D3DXSaveTextureToFileW(frameName.str().c_str(),D3DXIFF_BMP,tex,NULL);

If you want to store the result of frameName.str() use a std::wstring.