glGetIntegerv (GL_STENCIL_BITS, &bit);
PowerVR MBX does not support stencil so this query will always return 0 on platforms with MBX. If you tell us what you’re trying to achieve we might be able to suggest alternative methods.
The shadow volumes will use the stencil buffer, and now I have no idear except use the shadow map technology. But I want to use the shadow volumes, it means must use the stencil buffer. How can I do?
I’m afraid there’s not much you can do. The absence of subtractive blending means using blending to count front and back faces of shadow volumes is not a viable option either.