Device类是DirectX里的所有绘图操作所必须的。可以把这个类假想为真实的图形卡。场景里所有其他图形对象都依赖于device。HLSL的内容-DirectX Device class is where all the necessary graphics operations. This class can be hypothetical to the real graphics card. All other graphic objects in the scene are dependent on the device. HLSL content