Nokia API的问题

[gln]

com.nokia.mid.ui.DirectGraphics这个接口中有个方法:

drawPixels(byte[] pixels, byte[] transparencyMask, int offset, int scanlength, int x, int y, int width, int height, int manipulation, int format)

其中倒数第二个参数是什么意思?怎么样使用?我看了好多例子程序,这个参数都设置为0

API文档上这个参数是这样解释的:
manipulation - the manipulation done to the image before the draw, 0 means none.
不太明白...

[cxc014]

Manipulation parameters to drawPixels are formed by bitwise ORring FLIP_HORIZONTAL or FLIP_VERTICAL with a degree value: ROTATE_90, ROTATE_180 or ROTATE_270. Currently only these fixed rotation values are supported. The image is rotated counter-clockwise. The result from a combined manipulation is that first the rotation will be done, then the vertical flip, and finally the horizontal flip. Since the manipulation parameters are passed in a single integer the MIDlet cannot dictate the order of flips or rotation. There is always at most a single rotation, a single horizontal flip and a single vertical flip done. For instance, if a manipulation argument is: (FLIP_HORIZONTAL | FLIP_VERTICAL | ROTATE_90 ), the image is rotated 90 degrees counter-clockwise and after that it is flipped vertically and then horizontally. In methods that have anchor point parameter the manipulation is done before any anchor point is considere and the anchor point is applied after the manipulation.