when using glGetString on the enum GL_SHADING_LANGUAGE_VERSION I get only one value for return, while I was expecting space separated values as with glGetString(GL_EXTENSIONS).

what is even more confusing is that when I use glGetIntegerv(GL_NUM_SHADING_LANGUAGE_VERSIONS, *); I get a number bigger than one, and when I use glGetStringi(GL_SHADING_LANGUAGE_VERSION, i), and iterate over them I can get all the values. So, why don't I get all the values with glGetString(GL_SHADING_LANGUAGE_VERSION). I just get one value

CodePudding user response：

It is this way because that's how the feature was originally defined. All GLSL versions are backwards compatible with prior ones, so the expectation was that if you had a 1.10 shader, you could feed it to any implementation that accepted 1.10 or higher.

But with the break between core and compatibility, that become untenable. Making core implementations tacitly support GLSL shaders that included removed constructs made no sense. So there had to be a way for an implementation to specify exactly which GLSL versions it supported. But they couldn't change the existing version string's definition, so they (eventually) just added a new, indexed-based query.