Code review comment for lp:~widelands-dev/widelands/graphics

Some quick responses:

Output:
- The log contains "Using GL2/GL4 blit path/terrain rendering path" after the "END GRAPHICS REPORT" line

Build errors:
- I'll have a look at the glbinding variant.
- I ran the debug build which complained about style errors which I then fixed. Guess I was too naive to assume that that includes a comprehensive set of checks...

Running, performance, etc:
- Yes, MacOSX is unfortunately pretty crappy at keeping up with modern OpenGL. It's really surprising that Apple gets away with that, to be honest.
- GLES: All the required extensions are actually part of GLES 3.1, despite the GL4 name
- I understand the desire to keep things simple.
- The minimap renderer can probably be used without additional extensions.
- Terrain rendering and the blit path are trickier. Blitting could use instancing instead of SSBOs, but that's probably more of a step backwards (tiny instances aren't very efficient). Terrain rendering needs the table of terrain types in the vertex and fragment shaders; those should fit into a UBO instead of an SSBO, but that still requires an extra extension. Perhaps old-style uniforms could be used as well? I need to look up the available limits for that - it might be possible, but it might not be.

So, I'd give up on the separate blit path without extra extensions. Terrain rendering might be possible, but I need to look into it again. Minimap rendering is probably possible, and is the biggest win anyway.