rexguo

1. The texture target needs to be GLES20.GL_TEXTURE_EXTERNAL_OES instead of GL_TEXTURE_2D, e.g. in the glBindTexture calls and glTexParameteri calls.

2. In the fragment shader define a requirement to use the extension:
#extension GL_OES_EGL_image_external : require

3. For the texture sampler used in the fragment shader, use samplerExternalOES instead of sampler2D.

Everything below here is all in the C code, no more Java.

4. In the C code, use glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, eglImage) to specify where the data is, instead of using glTexImage2D family of functions.