Ask a questions about opengl/directx access memory image data,
1, it is said that it can be make setrendertarget output to the surface, or directly lock the back buffer,
Don't know to how to get behind?
2, from front desk buffer data

 extern IDirect3DDevice9 * g_pd3dDevice; 
Void CaptureScreen () 
{
IDirect3DSurface9 * pSurface; 
G_pd3dDeviceaCreateImageSurface (ScreenWidth ScreenHeight, 
D3DFMT_A8R8G8B8, & amp; PSurface); 
G_pd3dDevice - & gt; GetFrontBuffer (pSurface); 
D3DXSaveSurfaceToFile (" Desktop. BMP, "D3DXIFF_BMP pSurface, 
NULL, NULL); 
PSurface - & gt; Release (); 
} 

Don't know how to fetch the data from the background backbuffer? Have a great god can communicate, share experience, GetFrontBuffer is a relatively slow operation, design is so so, so in critical applications should avoid to use efficiency,
Experienced friend hopes to be able to teach the younger brother get a little experience in how to use GetBackBuffer and exchange chain memory method or way of back-end data,