OpenGL texture compression support , android

http://developer.android.com/intl/zh-tw/guide/topics/graphics/opengl.html#textures

The Android framework provides support for the ETC1 compression format as a standard feature,
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Beyond the ETC formats, Android devices have varied support for texture compression based on their GPU chipsets and OpenGL implementations.

如果真的要使用特定的 TC 功能，記得宣告在 manifest 中：

Note: Once you decide which texture compression formats your application will support, make sure you declare them in your manifest using <supports-gl-texture> . Using this declaration enables filtering by external services such as Google Play, so that your app is installed only on devices that support the formats your app requires. For details, see OpenGL manifest declarations.

google playstore 會依照 manifest 內容，決定用戶的手機能不能安裝該程式：

Each time you upload an application to the Google Play Developer Console, Google Play scans the application's manifest file and looks for any elements. It extracts the format descriptors from the elements and stores them internally as metadata associated with the application .apk and the application version.

When a user searches or browses for applications on Google Play, the service compares the texture compression formats supported by the application with those supported by the user's device. The comparison is based on the format descriptor strings and a match must be exact.

If any of an application's supported texture compression formats is also supported by the device, Google Play allows the user to see the application and potentially download it. Otherwise, if none of the application's formats is supported by the device, Google Play filters the application so that it is not available for download.

http://developer.android.com/intl/zh-tw/guide/topics/manifest/supports-gl-texture-element.html#market-texture-filtering