Hi Guys,

I have just noticed that when I run my program with the DX Control Panel set to use the debug mode, I get an error every draw call.

Direct3D9: (ERROR) :Vertex buffer must be unlocked during DrawPrimitive call
Direct3D9: (ERROR) :DrawPrimitive failed.

This is the code I am using to render a single quad. Nothing else is happening in the draw call that reports any errors (i.e. If I comment out this source the program doesnt report any errors)

if(!FAILED(pVertexSpriteObject->Lock(0,(nNumVerts)*sizeof(D3DVERTEX),&pVertexBuffer,D3DLOCK_DISCARD)))
{
	pVertexSpriteObject->Lock(0,(nNumVerts)*sizeof(D3DVERTEX),&pVertexBuffer,D3DLOCK_DISCARD);

	memcpy(pVertexBuffer,vertices,(nNumVerts)*sizeof(D3DVERTEX));
	
	Renderer->DeviceHandle()->SetStreamSource(0,pVertexSpriteObject,0,sizeof(D3DVERTEX));
	Renderer->DeviceHandle()->SetFVF(D3DFVF_XYZRHW|D3DFVF_DIFFUSE|D3DFVF_TEX1);

	pVertexSpriteObject->Unlock();
	Renderer->DeviceHandle()->DrawPrimitive(D3DPT_TRIANGLESTRIP,0,nNumVerts-2);
}

As far as I can see, I am unlocking the vertex buffer with pVertexSpriteObject->Unlock();.

I have tried moving that line below DrawPrimative() but get the same error.

Any chance anyone could advise on what I am doing wrong?

Thanks in advance

Damn, what a stupid mistake. I saw what is wrong straight after I posted this (must be the different font - LOL)

I am locking the vertex buffer twice in a row.