Locks a rectangle on a texture resource.
HRESULT LockRect( [in] UINT Level, [out] D3DLOCKED_RECT *pLockedRect, [in] const RECT *pRect, [in] DWORD Flags );
- Level [in]
Specifies the level of the texture resource to lock.
- pLockedRect [out]
Pointer to a D3DLOCKED_RECT structure, describing the locked region.
- pRect [in]
Type: const RECT*
Pointer to a rectangle to lock. Specified by a pointer to a RECT structure. Specifying NULL for this parameter expands the dirty region to cover the entire texture.
- Flags [in]
Combination of zero or more locking flags that describe the type of lock to perform. For this method, the valid flags are:
You may not specify a subrect when using D3DLOCK_DISCARD. For a description of the flags, see D3DLOCK.
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be D3DERR_INVALIDCALL.
Textures created with D3DPOOL_DEFAULT are not lockable. Textures created in video memory are lockable when created with USAGE_DYNAMIC.
For performance reasons, dirty regions are recorded only for level zero of a texture. Dirty regions are automatically recorded when IDirect3DTexture9::LockRect is called without D3DLOCK_NO_DIRTY_UPDATE or D3DLOCK_READONLY. See IDirect3DDevice9::UpdateTexture for more information.
The only lockable format for a depth-stencil texture is D3DLOCK_D16_LOCKABLE.
Video memory textures cannot be locked, but must be modified by calling IDirect3DDevice9::UpdateSurface or IDirect3DDevice9::UpdateTexture. There are exceptions for some proprietary driver pixel formats that Direct3D 9 does not recognize. These can be locked.
This method cannot retrieve data from a texture resource created with D3DUSAGE_RENDERTARGET because such a texture must be assigned to D3DPOOL_DEFAULT memory and is therefore not lockable. In this case, use instead IDirect3DDevice9::GetRenderTargetData to copy texture data from device memory to system memory.