If you switch to/from a compute shader and the other shader is either
nil or a graphics shader, clear bindings.
Maybe if you switch to/from nil the bindings shouldn't be cleared, but
this is a bit more complicated to implement and it's not clear that
there's any reason not to treat nil shaders as graphics shaders.
Previously, if you wanted to run compute operations that depend on the
results of prior compute operations, you had to put these in 2 different
passes, because logically all of the compute calls in a pass run "at the
same time" (or we're at least giving the GPU the freedom to do that).
Having to set up an entirely new pass just to synchronize 2 :compute
calls is pretty cumbersome, and incurs extra overhead. It would be
possible to change things so *every* :compute call waits for previous
computes to finish, but this would destroy GPU parallelism.
The Pass:barrier method lets compute calls within a pass synchronize
with each other, without requiring multiple passes. Adding a barrier
basically means "hey, wait for all the :compute calls before the barrier
to finish before running future :computes".
This lets things remain highly parallel but allows them to be easily
synchronized when needed.
Pass stores draw commands rather than sending them to Vulkan
immediately.
The main motivation is to allow more flexibility in the Lua API. Passes
are now regular objects, aren't invalidated whenever submit is called,
and can cache their draws across multiple frames. Draws can also be
internally culled, sorted, and batched.
Some API methods (tallies) are missing, and there are still some bugs to
fix, notably with background color.
View count is well-defined to be 2 with the current view configuration,
and people should be able to rely on getViewCount even before the views
are tracked. It returns the number of views in the view configuration,
not the number of views with valid data.
- If timestamp is zero (before .update is called), return empty data
instead of erroring.
- Check for valid position/orientation separately, and return empty data
for anything that's invalid. Previously both position/orientation
were used if either was valid, which returns undefined results.
- Add Buffer:newReadback
- Add Buffer:getData
- Buffer:getPointer works with permanent buffers
- Buffer:setData works with permanent buffers
- Buffer:clear works with permanent buffers
- Add Texture:newReadback
- Add Texture:getPixels
- Add Texture:setPixels
- Add Texture:clear
- Add Texture:generateMipmaps
- Buffer readbacks can now return tables in addition to Blobs using Readback:getData
Tally is coming back soon with an improved API, it's temporarily removed
since it made the transfer rework a bit easier.
Note that synchronous readbacks (Buffer:getData, Texture:getPixels)
internally call lovr.graphics.submit, so they invalidate existing Pass
objects. This will be improved soon.
Pass:plane was leaving its z scale uninitialized, which resulted in
a garbage normal matrix and other issues when using the transform in a
shader. Planes were the only shape affected by this.
