The variable is already dereferenced both before and after this
check which means that if this variable would ever be zero it would
have crashed dolphin already.
The old way was to use big switch/case statements based on a type of buffer.
The new one is to use inheritance.
This change prohibits us to change the buffer type while running, but I doubt we'll ever do so.
Performance should also be a bit better. Also a nice cleanup.
Added some comments about this different kind of buffers.
This is a bit slower on map_and_* because of flushing and _very_ much slower on buffer(sub)?data because of a new memcpy.
But this design allow us to decode directly into a gpu buffer, eg vertexloader will profit :)
This one was introduced to reduce the glBindTexture and glActiveTexture calls. But it was quite a bit of logic and only an improvment on uploading/creating a texture, which is done rarely.
We are used to render them out of order as long as everything else matches, but rendering order does matter, so we have to flush on primitive switch. This commit implements this flush.
Also as we flush on primitive switch, we don't have to create three different index buffers. All indices are now stored in one buffer.
This will slow down games which switch often primitive types (eg ztp), but it should be more accurate.
This "u32 components" is a list of flags which attributes of the vertex loader are present.
We are used to append this variable to lots of vertex generation functions, but some of them don't need it at all.
degasus