Bitmap buffering (Bitmap Caching)
How does a flash animation play? In fact, it is the Flash Player to the source file can see the frame of a frame of the picture, of course, before the drawing need to process each frame within the code
Flash playback speed by what decision
The speed of a flash display is determined by the FPS set by the creator, but because of the difference between the machine configuration and the operating system, the FPS may be set too high in some low configuration machines, and in fact, All set FPS is actually the maximum frame frequency that flash can play to. In the same environment, the complexity of the picture determines the speed of the drawing.
The meaning of bitmap buffering
Because most of the flash is vector computing, so when drawing a very complex picture, or frequently copy some of the screen, it is bound to use a lot of time, and these times should be omitted. Bitmap buffering design is aimed at this, he can put an MC, first draw again, The information is placed in a prepared device, and when the MC is reused without shape change, Flash player does not redraw the MC each time, but reads the information from the device and displays it, which greatly increases the speed
The usefulness of bitmap buffering
Imagine, in an application that is full of Windows components, each window can be dragged and dragged, this time if not set bitmap buffer, then it is conceivable that Flash player in each frame, all the window components to the screen, a draw, it is very scary!
Bitmap buffer points of attention
Help inside also said, for very little use of rotation, scaling, variant of the MC use bitmap buffer will greatly improve the speed, this is also because, if the above operation, it destroys the shape of the MC, Flash player has to go back to "know" the MC, the result of this, Might be worse than not having a bitmap buffer set.
Use of bitmap buffering
In the Flash IDE Select a MC,CTRL+F3 (property panel), the hook-and-click Bitmap Buffer (CACHEASBITMAP) can be as words Mc.cacheasbitmap = True can be two are connected, When Cacheasbitmap is already selected in the IDE, the Mc.cacheasbitmap in the program is already true, and vice versa
Animation understanding:http://weblogs.macromedia.com/md/archives/2005/10/flash_8_animati_3.cfm
Application Example of bitmap buffering:http://www.flashguru.co.uk/maelstrom/?example=isometric%20grid%20image
Reference article:http://mxdj.sys-con.com/read/142694.htm