DirectX アルファ合成

加算合成

	g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
	g_pd3dDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_ONE);
	g_pd3dDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ONE);

半加算合成

	g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
	g_pd3dDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_ONE);
	g_pd3dDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);