IDirect3DVertexBuffer9::Lock和IDirect3DIndexBuffer9::Lock

IDirect3DVertexBuffer9::Lock

Locks a range of vertex data and obtains a pointer to the vertex buffer memory.

HRESULT Lock( UINT OffsetToLock,自缓存的起始点到开锁定的位置的偏移量 UINT SizeToLock,所要锁定的字节数 VOID ** ppbData,指向锁定存储区的起始位置的指针 DWORD Flags改标记描述了锁定方式 ); 

注：当OffsetToLock和SizeToLock都为0时，锁定整个缓存 

Parameters

OffsetToLock

[in] Offset into the vertex data to lock, in bytes. To lock the entire vertex buffer, specify 0 for both parameters, SizeToLock and OffsetToLock.

SizeToLock

[in] Size of the vertex data to lock, in bytes. To lock the entire vertex buffer, specify 0 for both parameters, SizeToLock and OffsetToLock.

ppbData

[out] VOID* pointer to a memory buffer containing the returned vertex data.

Flags

[in] Combination of zero or more locking flags that describe the type of lock to perform. For this method, the valid flags are:

• D3DLOCK_DISCARD
• D3DLOCK_NO_DIRTY_UPDATE
• D3DLOCK_NOSYSLOCK
• D3DLOCK_READONLY
• D3DLOCK_NOOVERWRITE

For a description of the flags, see D3DLOCK.

IDirect3DIndexBuffer9::Lock

Locks a range of index data and obtains a pointer to the index buffer memory.

HRESULT Lock( UINT OffsetToLock, UINT SizeToLock, VOID ** ppbData, DWORD Flags ); 

Parameters

OffsetToLock

[in] Offset into the index data to lock, in bytes. Lock the entire index buffer by specifying 0 for both parameters, SizeToLock and OffsetToLock.

SizeToLock

[in] Size of the index data to lock, in bytes. Lock the entire index buffer by specifying 0 for both parameters, SizeToLock and OffsetToLock.

ppbData

[out] VOID* pointer to a memory buffer containing the returned index data.

Flags

[in] Combination of zero or more locking flags that describe the type of lock to perform. For this method, the valid flags are:

• D3DLOCK_DISCARD
• D3DLOCK_NO_DIRTY_UPDATE
• D3DLOCK_NOSYSLOCK
• D3DLOCK_READONLY
• D3DLOCK_NOOVERWRITE

For a description of the flags, see D3DLOCK.