Floating Point Textures in OpenGL ES 2.0

I've been trying to figure out how to use float textures in GLES2. The API Reference says that only unsigned b开发者_如何学编程ytes and shorts can be used, but I've seen people saying it is supported elsewhere.

I could use GL_LUMINANCE as the texture format but that only gets me one float value.

In OpenGL ES 2.0, floating-point textures are only supported if the implementation exports the OES_texture_float extension. Note that this extension only allows nearest filtering within a texture level, and no filtering between texture levels. This restriction is loosened by the presence of OES_texture_float_linear. Another potential caveat is that the presence of OES_texture_float does not require that the implementation support rendering to floating-point textures with framebuffer objects.

What are you trying to do with float textures?