What version of OpenGL is closest to OpenGL ES2?

Question

I've been trying to work with OpenGL ES 2 in Android for some time now, but I'm finding the lack of experience with OpenGL itself to be an issue, since I barely understand what all the GLES20 methods actually do. I've decided to try to learn actual OpenGL, but a little bit of reading has informed me that each version of OpenGL is drastically different from its predecessor. Wikipedia isn't very clear on which version that OpenGL ES2 most closely resembles.

So, my question is, which version of OpenGL should I learn for the purpose of better understanding OpenGL ES2?

Answer 1

According to the book OpenGL ES 2.0 Programming Guide:

The OpenGL ES 1.0 and 1.1 specifications implement a fixed function pipeline and are derived from the OpenGL 1.3 and 1.5 specifications, respectively. The OpenGL ES 2.0 specification implements a programmable graphics pipeline and is derived from the OpenGL 2.0 specification.

Answer 2

OpenGL ES 2.0’s closest relative is OpenGL 2.0. Khronos provides a difference specification, which enumerates what desktop OpenGL functionality was removed to create OpenGL 2.0. The shading language for OpenGL ES 2.0 (GLSL ES 1.0) is derived from GLSL 1.20.

Answer 3

OpenGL ES2.0 is almost one-to-one copy of WebGL.

The differences are practically only in the setup of the environment, which in Android happens with EGL and which happens in WebGL with calls to DOM methods. (setting canvas)

The comparison to "open gl" is next to impossible, as Open GL means almost fixed and hidden rendering pipeline, which is controlled by stack of matrices and attributes. This is now obsoleted in ES. Instead one has the "opportunity" to control almost every aspect of the rendering pipeline.