Developing Android Applications with Adobe AIR

GPU Rendering on Android

The rendering mode used for Android is called GPU Vector. Both the creation of individual pixel buffers and scene compositing are done by the GPU. The GPU is particularly useful in this performance-constrained environment.

The GPU rendering technique only benefits vector art. It reduces the time needed to rasterize vector graphics, especially complex ones, to a bitmap. A bitmap is already a pixel buffer, also called a texture. There is no need to duplicate it. In fact, doing so would waste precious memory.

To perform GPU rendering in Android using Flash Professional, go to File→AIR Android settings. Select the General tab, and under Render Mode, select GPU.

In Flash Builder, set the renderMode node of the initialWindow node of your application descriptor to gpu:

<initialWindow>
<renderMode>gpu</renderMode>
...

If the user has a device that does not perform hardware acceleration, or if it does not work reliably with its drivers, AIR ignores the setting. No message is dispatched.

The cacheAsBitmap Property

The cacheAsBitmap property was added in Flash 8 with the Surface Renderer. Its purpose is to optimize the animation of vector graphics along the x- and y-axes, a process called translation.

When the cacheAsBitmap property is set to true, the display object rendered as a bitmap is cached in memory for reuse, as shown in Figure 14-1.

Figure 14-1. Taking vector graphics ...