Render to Texture using FBO in OpenGL ES 2.0 and EGL on Windows. This is effectively chapter 12 in: Open GL ES 2 Programming Guide There is example code, but not for chapter 12.
I used the Angle Lib to build the OpenGL ES library. The compiled library is checked in for convenience to the debug and release directories. I used Visual Studio 2013 to compile everything.
The OpenGL ES spec is here: https://www.khronos.org/registry/gles/specs/2.0/es_full_spec_2.0.25.pdf . I never used it.