OpenGL 4 adoption

Question

Having only recently started learning the 'new' OpenGL (programmable as opposed to fixed-function, I learned from the Nehe Tutorials), I'm wondering if learning OpenGL 3 is at all useful since OpenGL 4 was released.

The reason I ask is because I'm wondering as to the number of machines able to use OpenGL 4.

Is it widely adopted currently, do most graphics cards support it? Is OpenGL 4 even radically different from OpenGL 3?

Answer 1

OpenGL 4 is not radically different from OpenGL 3. It supports binary shaders and 64-bit data types and some other things, but nothing that makes your OpenGL 3 apps immediately obsolete.

Answer 2

As above, but if you want to learn the modern way to use OpenGL, I recommend you only use the core profile, and not the deprecated bits (fixed func...). You can either make the GL fail on calling obsolete functions, or run your app through gDEBugger (free) which will give you warnings.