OpenGL: What's the deal with deprecation?

Question

OpenGL 3.0 and 3.1 have deprecated quite a few features I find essential. In particular, the use of fixed function in shaders.

Can anyone explain what\'s really th

Answer 1

OpenGL allows for both a 'core' profile and a 'compatibly' profile. So for most systems you wont loose any kind of access to deprecated or removed functions.

But if you want to ensure compatibly it is best to stick to the core stuff. You won't be guaranteed a compatibility profile (even if most hardware has one and at the current state it's more likely you will encounter an out of date OpenGL rather than a core only one). Also OpenGL ES is now a subset of OpenGL, it is possible to write a OpenGL ES 2.x/3.x program and have it run in OpenGL 4.3 with almost no changes.

Game console like the PlayStations and the Nintendo ones shipped with their own graphics libraries rather than using OpenGL.

They were based on OpenGL but here stripped down in a similar was to ES (I don't think ES 2.0 was out then). Those systems need to write their own graphics drivers and libraries, asking a hardware vendor to write what is basically a whole load of legacy wrapping libraries is a bit much (all the fixed function stuff would just end up being implemented in shaders at some stage and it's likely that glBegin/glEnd would just be getting turned into a VBO automatically anyway).

I think it has also been important to ensure that developers are made aware of the current way they should be programming. For decades people have been taught the 'wrong' way to do things by default and vertex buffer objects have been taught as an extra.