How do I know what version of OpenGL does a source code use?

Question

I got a code, but I dont know which version of OpenGl it uses.

There were no #version pragma in the code, so I find it difficult to figure out.

How do I know which version of OpenGl is it designed for?

Additional Info:

It got shader and there were vec2 , vec3 , vec4

Answer 1

If you look at the OpenGL reference pages, for every function there's a list indicating in which version it appeared. The list starts at OpenGL-2.0, but that's really the lowest version you have to care about, these days.

Anyway, here's a set of heuristics to determine the OpenGL version used:

• makes use of buffer objects, ie calls to glBufferData are made → v >= 1.5

• makes use of GLSL shaders → v >= 2.0

• GLSL code uses keywords varying and uniform → v < 3

• makes use of framebuffer objects, ie calls to glBindFramebuffer are made → v >= 3.0

• makes use of vertex array objects, ie calls to glBindVertexArray are made → v >= 3.3 core profile

• makes use of glTextureStorage… / glTexStorage… → v >= 4.2