Re: When does the surface UnlockRect

David Hunt — Wed, 14 May 2008 15:49:19 GMT

You cannot unlock the surface until you are done accessing the pixel data. Once unlocked, the memory pointed to can (and likely will) be invalid.

When does the surface UnlockRect

akira32 — Wed, 14 May 2008 11:13:41 GMT

Can I timely let surface UnlockRect after LockRect.
Is the "<==position1"(line9) surface UnlockRect postion correct? Does it have any probelm about the pointer of "lrect_New.pBits"?

  HRESULT hr;

  LPDIRECT3DSURFACE9 pDestSurface_New;
  D3DLOCKED_RECT lrect_New;
  D3DSURFACE_DESC Desc;

  m_QVSM_pShadowMapSurf_Common->GetDesc(&Desc);
  V(m_pd3dDevice->CreateOffscreenPlainSurface(Desc.Width,Desc.Height,Desc.Format,D3DPOOL_SYSTEMMEM,&pDestSurface_New,NULL));//Must be D3DPOOL_SYSTEMMEM for MSDN
  V(m_pd3dDevice->GetRenderTargetData(m_QVSM_pShadowMapSurf_Common,pDestSurface_New));

  hr=pDestSurface_New->LockRect(&lrect_New,NULL,D3DLOCK_NO_DIRTY_UPDATE|D3DLOCK_READONLY);
  //hr=pDestSurface_New->UnlockRect();//<==position1

  for (LONG y=0;y<(LONG)Desc.Height;y++)
  {
    DWORD dwOffset = y*Desc.Width;

    for (LONG x=0;x<(LONG)Desc.Width;x++)
    {
      //float dwColor_New = ((float*)lrect_New.pBits)[y*(lrect_New.Pitch/sizeof(float))+x];//Y*Width+X
      float dwColor_New = ((float*)lrect_New.pBits)[y*Desc.Width+x];//Y*Width+X
      int c=12;
    }
  }

  hr=pDestSurface_New->UnlockRect();//<==position2

  SAFE_RELEASE(pDestSurface_New);

Direct3D

Re: When does the surface UnlockRect

When does the surface UnlockRect