Because the new arr.h contains an array on the stack, we can't
initialize it and then copy it, or the pointer to the stack array
will be pointing to the wrong thing, causing incorrect behavior.
- If you have an instanced batch, it will use the instanced mesh. That
has a drawID attribute that uses the identity buffer, which has a vertex
divisor. BUT if you only have one instance, then we won't emit an
instanced draw, and the use of a divisor'd attribute w/ a non-instanced
draw is causing mega problems on macOS.
- This also fixes observed macOS bugs like:
- Needing to have a small UBO
- Flickering at startup
- Flicker when writing to the last byte of a UBO
- etc.
- Also make the generic attribute value for lovrDrawID more correct (scalar instead of vector).
- Rename drawMode to topology in some places.
- Batch uses DrawCommand internally to simplify stuff.
- Do less work while flushing.
- Store global head/tail cursors instead of unused per-batch cursors.
Having a normal Canvas object that represents the backbuffer reduces
some indirection where we have to last-minute check if a Canvas is
set. It also means that all of the draw-related info that was _sometimes_
on the Canvas is now _always_ on the Canvas, which reduces the amount
of redundant information we need to provide for a draw call.
There may be some issues related to changing the width/height/stereo
of the default Canvas.
- Ref struct only stores refcount now and is more general.
- Proxy stores a hash of its type name instead of an enum.
- Variants store additional information instead of using a vtable.
- Remove the concept of superclasses from the API.
- Clean up some miscellaneous includes.
bjorn