Other ways to improve display object performance
Hardware acceleration can speed up graphics performance
in some classes of display objects Here are a few tips on how to
maximize graphics performance:
Try to limit the numbers of items visible on stage.
Each item takes some time to render and composite with the other
items around it.
When you no longer need to display a display
object, set its
remove it from the stage (
). Do not simply
property to 0.
Avoid blend modes in general, and the layer blend mode in
particular. Use the normal blend mode whenever possible.
Display object filters are expensive computationally. Use
them sparingly. For example, using a few filters on an introduction
screen may be acceptable. However, avoid using filters on many objects
or on objects that are being animated or when you must use a high
Avoid morph shapes.
Avoid using clipping.
If possible, set the
Don't overdraw. Use the background color as a background.
Don't layer large shapes on top of each other. There is a cost for
every pixel that must be drawn. This is particularly true for display
objects that are not hardware accelerated.
Avoid shapes with long thin spikes, self intersecting edges,
or lots of fine detail along the edges. These shapes take longer
to render than display objects with smooth edges. This is particularly
true for display objects that are not hardware accelerated.
Make bitmaps in sizes that are close to, but less than, 2
bits. The dimensions do not have to be power of 2,
but they should be close to a power of 2, without being larger.
For example, a 31-by-15–pixel image renders faster than a 33-by-17–pixel
image. (31 and 15 are just less than powers of 2: 32 and 16.) Such
images also use memory more efficiently.
Limit the size of display objects to 1024 x 1024 pixels (or
2048 x 2048 on newer devices).