I am trying to figure out how much work is involved in upgrading an existing 3.2 application to become 4.2 core compliant so I can use some debuggers out there that require this as a prerequisite. What all do i need to change - where can i get my hands on a complete list of major changes instead of pouring through the code and wondering if this is compatible or not ? I certainly don’t think using the “#version 420 compatibility” in the shader isn’t going to be enough.
The double-negative in your last sentence aside, “upgrading” from 3.2 to 4.2 requires nothing. Not even changing your shading language versions, because OpenGL 4.2 requires that implementations support every GLSL version from 1.40 (and in practice, every non-MacOSX implementation will support every version of GLSL).
If your code worked under 3.2 compatibility, it will work under 4.2 compatibility. If your code worked under 3.2 core, it will work under 4.2 core. Without any code changes.
OpenGL is not Direct3D; the API does not radically alter itself with every major version number. OpenGL has only had one event of removing functionality from the API: the changeover from 3.0 to 3.1. All 3.1 code is therefore compatible with every later version of OpenGL.
thanks! that comes as a big relief.