void SetDrawMode(int mode)   
{   
	switch(mode)   
	{   
	case DM_Normal:   
		D3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);   
		D3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);   
		D3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_ADD);   
		break;   
	case DM_NoBlend:   
		D3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_ONE);   
		D3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ZERO);   
		D3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_ADD);   
		break;   
	case DM_Add:   
		D3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);   
		D3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ONE);   
		D3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_ADD);   
		break;   
	case DM_Subtract:   
		D3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);   
		D3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ONE);   
		D3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_REVSUBTRACT);   
		break;   
	case DM_Multiply:   
		D3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_DESTCOLOR);   
		D3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ZERO);   
		D3DDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_ADD);   
		break;   
	}   
}