by Graf Zahl » Tue Dec 18, 2018 2:13 am
The vintage version is a fallback case for old hardware. Old hardware also imnplies "slow".
If a hardware accelerated feature like multisampling is too costly, what do you think a shader-based postprocessing effect would take? It'd be even slower than multisampling!
Never forget: These old Intel chipsets for which the vintage build is mainly designed are SLOW! To get some semi-decent performance out of them, anything that may cost time has been either disabled or simplified to avoid costly processing paths. That by its very nature includes all postprocessing of any kind because it'd require rendering to a buffer and then again to the screen. On modern hardware that is nearly free, but on these old chupsets it can really slow down things.
Last but not least, the GZDoom 3.5 survey showed that merely 2.5% of all our users run hardware that needs the vintage build,and that number is declining. It'd be a disservice to the remaining 97.5% to put any focus on such old and slow hardware. We can consider ourselves lucky that we have found a developer who is willing to do this thing. Aside from the cost-benefit ratio, with all main developers of GZDoom having a modern graphics card, we are simply in no situation to do any optimization for OpenGL 2.x anymore, because its performance characteristics are totally different from later graphics hardware. And like Rachael said, the continued support of this is a subject of ongoing discussions. Over the last half year the code has already diverged enough to make it difficult to keep both builds in sync.
The vintage version is a fallback case for old hardware. Old hardware also imnplies "slow".
If a hardware accelerated feature like multisampling is too costly, what do you think a shader-based postprocessing effect would take? It'd be even slower than multisampling!
Never forget: These old Intel chipsets for which the vintage build is mainly designed are SLOW! To get some semi-decent performance out of them, anything that may cost time has been either disabled or simplified to avoid costly processing paths. That by its very nature includes all postprocessing of any kind because it'd require rendering to a buffer and then again to the screen. On modern hardware that is nearly free, but on these old chupsets it can really slow down things.
Last but not least, the GZDoom 3.5 survey showed that merely 2.5% of all our users run hardware that needs the vintage build,and that number is declining. It'd be a disservice to the remaining 97.5% to put any focus on such old and slow hardware. We can consider ourselves lucky that we have found a developer who is willing to do this thing. Aside from the cost-benefit ratio, with all main developers of GZDoom having a modern graphics card, we are simply in no situation to do any optimization for OpenGL 2.x anymore, because its performance characteristics are totally different from later graphics hardware. And like Rachael said, the continued support of this is a subject of ongoing discussions. Over the last half year the code has already diverged enough to make it difficult to keep both builds in sync.