====== PC_LockOverlay import ======
Plugin can use this function together with [[plugin_sdk:imports:pc_unlockoverlay|PC_UnlockOverlay]] to draw overlay in [[plugin_sdk:exports:pluginupdateoverlay|PluginUpdateOverlay]] callback. Function locks system memory buffer which will be used to update overlay texture.

==== Syntax ====
<code>
PLUGIN_IMPORT BOOL PC_LockOverlay(
    [in] DWORD dwPluginID,
    [in] OverlayLockStruct *map_desc
);
</code>

==== Parameters ====
dwPluginID [in]\\
Unique plugin ID, see more here: [[plugin_sdk:exports:plugininit|PluginInit]].

map_desc [in]\\
Not NULL address of [[plugin_sdk:structures:overlaylockstruct|OverlayLockStruct]] which receives information about locked memory area, which represents overlay image buffer (only for writing by plugin). Buffer has format RGB32 (DWORD: 0xAABBGGRR). Plugin should fill this buffer with graphics and then unlock it.

==== Return value ====

TRUE is lock operation is successful. FALSE if it isn't.

==== Sample code ====

<code>
// global variable to store plugin id
DWORD m_dwPluginID = -1;
 
PLUGIN_EXPORT void PluginUpdateOverlay()
{
	// lock overlay image
	OverlayLockStruct pLock;
	if (!PC_LockOverlay(m_dwPluginID, &pLock))						// lock overlay buffer and get its size
		return;

	// copy rgb24 to rgba32, pImageFrame - pointer to rgb24 buffer
	for (DWORD y = 0; y < pLock.dwHeight; y++)
	{
		BYTE *pSrc = pImageFrame + y * pLock.dwWidth * 3;
		BYTE *pDst = pLock.pBuffer + y * pLock.dwPitch;

		for (DWORD x = 0; x < pLock.dwWidth; x++)
		{
			*pDst++ = *pSrc++;
			*pDst++ = *pSrc++;
			*pDst++ = *pSrc++;
			*pDst++ = 0xff; // alpha
		}
	}


	// fill overlay image
	PC_UnlockOverlay(m_dwPluginID, true);
}
</code>

==== See also ====

[[plugin_sdk:imports:pc_unlockoverlay|PC_UnlockOverlay]]\\
[[plugin_sdk:imports:start|PlayClaw plugin imports]]\\