carmine
openGL version depend on what is installed on my sytem or come togheter with DDnet?
The default for 64bit is 3.0 for ddnet. If thats not available it tries gl 2.0 then 1.4
Opengl 3.3 is the first renderer that tried to reduce cpu usage by buffering tile data instead of streaming(gl 2.0 and 3.0 do it partially for tiles )
Vulkan has much more control than opengl, especially over the memory management. This lead to an significant performance increase for steamed data, even compared to opengl 1.4 which is extremely optimized driver wise for this.
Additionally Vulkan was built with multi threading in mind to shift the same workload across multiple cores more easily. This e.g. is great for architectures like arm. It also results in less energy consumption, or likewise in more performance. Generally vk is lower level it doesn't do lot of stuff implicitly compared to opengl
The newer the renderer the more control the programmer got basically sums it up. U can e.g. Google static render pipeline vs dynamic render pipeline aka shaders
Generally even with shaders alone u could solve the problems of gl1.4 backend. But since the opengl core elvolved it got 2d texture arrays in ogl 3.0 which cleanly allow to render tile sets like tw uses without sacrificing performance or mipmapping.
Additionally to enhance mipmapping rendering the higher backends use linear interpolation between mipmaps and the resulting samlping. Also known as trilinear sampling u can also google it. Bilinear vs trilinear sampling .
So in general. Higher backends trade a small amount of gpu perf for better quality but in trade are much more cpu friendly because it allows buffering and manipulating over shaders and comes with new features that make ur life easier (edited)
