Android BitmapFactory.decodeStream loading BGR format?

I want to load .png file via asset manager which is provided by android sdk. AssetManager manager; /........./ BitmapFactory.decodeStream(manager.open(path));

It returns BGR format 开发者_运维百科data but opengl es 2.0 uses RGB format so , Blue seems red , red seems blue, how odd.

Is there any solution for it?

I use Nvıdia Tegra 2 (Android 2.2) device for test the application along with c++ via JNI.

You must know the number of bits for colors, let's say n bit is for a color, so the first n bit represents BLUE, the second n bits represent GREEN and the final n bits represent RED in the input. You need to swap these bit groups into the correct order, like this:

output = (input << (2 * n)) + (input << n >> n) + (input >> (2 * n));

To be able to use this solution you need to find out how much is n.

Recent versions of OpenGL, also provide BGR input formats; OpenGL-ES not, unfortunatly. Since you're on Android you have to deal with OpenGL-ES.

If you're using a fragment shader it is also trivial to apply a rgb→bgr swizzle, which if probably the easiest way to overcome this problem.