Optimization of Flash Platform Technology (12) use of alpha transparency reduction

Another way to improve performance is to delete the use of alpha transparency. When creating a transparency bitmap image, Alpha transparency increases the load on Flash Player, you can use the opaquebackground attribute to specify the background color to avoid this situation. When the opaquebackground attribute is used, the bitmap surface created in the memory still uses 32 bits. However, the Alpha offset has been set to 255 and transparency is not used. Therefore, when the bitmap cache function is used, the opaquebackground attribute will not reduce memory usage, but will improve the rendering performance.