强呀,果然是会自动拉伸到Power of Two的大小的,我碰到的问题还有一个就是当我使用D3DX_FILTER_NONE来不使用过滤的时候,原来800*600的图片就不能在800*600分辨率的屏上完全显示出来,现在想想,原来是自动拉伸到1024*1024了,所以无法全部显示出来了,一直都想不通这个问题,这次一下就解决了,哈哈,多谢各位高手!
下面引自 〈Real-time Rendering Tricks and Techniques in DirectX〉
Width,Height,and the Power of Two
Most graphics cards and implementations restrict texture dimensions to powers of two,This means that textures are restricted to sizes such as 1*1,16*16,128*128,and so on,Note that this dose not mean that they need to square.Sizes such as 128*16 are also legal.There are a couple of reasons for this restriction,but the biggest reason is that dimensions which are powers of two are easier for the decice to manipulate quichly.In future versions which are powers of two are easier for the device to manipulate quickly.In future versions of hardware,this requirement might be relaxed,but for the foreseeable future,you should expect that the hardware will require textures to have dimensions with powers of two.