Redraw regions

Always use the redraw regions option when building your project.

To improve rendering, it’s important to use the redraw regions option when building your project. Using this option allows you to see the regions that Flash Player is rendering and processing. You can enable this option by selecting Show Redraw Regions in the context menu of the debug version of Flash Player.

Note: The Show Redraw Regions option is not available in Adobe AIR or in the release version of Flash Player. (In Adobe AIR, the context menu is available only in desktop applications, but it has no built-in or standard items such as Show Redraw Regions.)

The image below illustrates the option enabled with a simple animated MovieClip on the timeline:

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Redraw regions option enabled

You can also enable this option programmatically, by using the flash.profiler.showRedrawRegions() method:

// Enable Show Redraw Regions 
// Blue color is used to show redrawn regions 
flash.profiler.showRedrawRegions ( true, 0x0000FF );

In Adobe AIR applications, this method is the only way to enable the redraw regions option.

Use redraw regions to identify opportunities for optimization. Remember that although some display objects are not shown, they still consume CPU cycles because they are still being rendered. The following image illustrates this idea. A black vector shape covers the animated running character. The image shows that the display object has not been removed from the display list and is still being rendered. This wastes CPU cycles:

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Redrawn regions

To improve performance, set the visible property of the hidden running character to false or remove it from the display list altogether. You should also stop its timeline. These steps ensure that the display object is frozen and uses minimal CPU power.

Remember to use the redraw regions option during the whole development cycle. Using this option prevents you from being surprised at the end of the project by unnecessary redraw regions and optimization areas that have been missed.