* minimal backend support for compute
- added api to dispatch a compute shader
- added api to create and bind a ssbo
- added api to read back a buffer
Only implemented in the gl backend
* Add a backend compute test suite
* basic support for compute shaders in matc
this is still very much work-in-progress.
We're not supporting images nor ssbo for now.
* rename UniformInterfaceBlock to BufferInterfaceBlock
* augment BufferInterfaceBlock to support ssbo features
- add support for std430
- add support for ssbo
- add support for variable-size array
- add support for memory qualifiers
* reformat MaterialBuilder
* material format: move subpasses outside of parameters
subpasses now are their own json property instead of being a
"parameter".
* refactor parameter() methods to match Buffer/SamplerInterfaceBlock
We're just shuffling the arguments.
* add support for buffers in .mat files
* filamat now generates buffer blocks (ssbo)
* take feature level into consideration when optimizing shaders
* don't store the 'uniform binding' chunk for level 2 materials
this includes some refactoring/cleanups of MaterialParser
* matinfo: fixes for compute
- separate subpasses from parameters
- don't attempt to print material properties
