Cocos2d VS Spring RTS game engine

As others have pointed out, the biggest difference you're seeing is likely due to the _version_ of OpenGL (and hence GLSL) version. That said, there are still important differences. I'd recommend looking at a comparison between the same shader in a project that supports both OpenGL & OpenGLES. For example, here's a shader from cocos2d-x https://github.com/cocos2d/cocos2d-x/blob/v4/cocos/renderer/shaders/positionColor.vert. Note the only difference in this case is the additional precision qualifier (lowp) for v_fragmentColor. Note too how cocos uses preprocessor macros to handle this, so they don't have to maintain separate shader sources. Depending on your goals, you might be interested in tools like Nvidia cg or nvFX that allow for creating shaders in a dialect agnostic way, but ymmv.

Speaking about markdown files on GitHub, I know that there are some repositories that have very stunning README markdown files, such as this one for Cocos2d-x, whcih includes images in conjunction with text. I might do the same for my repository as well. Considering VS Code have an extension for .md files, this might come in handy when I consider using VS Code to contribute to my game projects.

r/springrts: Spring is a versatile 3D RTS game engine. Using extensively Lua for scripting game-specific code to make nearly every aspect of the https://springrts.com/

Total Annihilation RTS. Really impressive for the hardware at the time, moddable, and super fun. The community has made SpringRTS and Beyond all Reason and last I heard Cavdog was essentially sold ~4 times and the original source code was lost. I still find the intro impressive considering it was released in 1997.

You may find this interesting: https://springrts.com

Also, if you want to play online: https://springrts.com/