In the new Draw Manager, when the same DrawGroup has both front and back facing instances, the front facing instances don't offset their indices accordingly.
Differential Revision: https://developer.blender.org/D17069
This implements the base needed for supporting multiple view concurently
inside the same drawcall.
The view used by common macros and view related functions is indexed using
a global variable `drw_view_id` which can be set arbitrarly or read
from the `drw_ResourceID`.
This is needed for EEVEE-Next shadow but can be used for other purpose
in the future.
Note that a shader specialization is needed for it to work. `DRW_VIEW_LEN`
needs to be defined to the amount of view the shader will access.
The number of views contained in a `draw::View` is set at construction
time.
Note that the maximum number of object correctly drawn by the shaders
using multiple views will be lower than thoses who don't.
This is a new implementation of the draw manager using modern
rendering practices and GPU driven culling.
This only ports features that are not considered deprecated or to be
removed.
The old DRW API is kept working along side this new one, and does not
interfeer with it. However this needed some more hacking inside the
draw_view_lib.glsl. At least the create info are well separated.
The reviewer might start by looking at `draw_pass_test.cc` to see the
API in usage.
Important files are `draw_pass.hh`, `draw_command.hh`,
`draw_command_shared.hh`.
In a nutshell (for a developper used to old DRW API):
- `DRWShadingGroups` are replaced by `Pass<T>::Sub`.
- Contrary to DRWShadingGroups, all commands recorded inside a pass or
sub-pass (even binds / push_constant / uniforms) will be executed in order.
- All memory is managed per object (except for Sub-Pass which are managed
by their parent pass) and not from draw manager pools. So passes "can"
potentially be recorded once and submitted multiple time (but this is
not really encouraged for now). The only implicit link is between resource
lifetime and `ResourceHandles`
- Sub passes can be any level deep.
- IMPORTANT: All state propagate from sub pass to subpass. There is no
state stack concept anymore. Ensure the correct render state is set before
drawing anything using `Pass::state_set()`.
- The drawcalls now needs a `ResourceHandle` instead of an `Object *`.
This is to remove any implicit dependency between `Pass` and `Manager`.
This was a huge problem in old implementation since the manager did not
know what to pull from the object. Now it is explicitly requested by the
engine.
- The pases need to be submitted to a `draw::Manager` instance which can
be retrieved using `DRW_manager_get()` (for now).
Internally:
- All object data are stored in contiguous storage buffers. Removing a lot
of complexity in the pass submission.
- Draw calls are sorted and visibility tested on GPU. Making more modern
culling and better instancing usage possible in the future.
- Unit Tests have been added for regression testing and avoid most API
breakage.
- `draw::View` now contains culling data for all objects in the scene
allowing caching for multiple views.
- Bounding box and sphere final setup is moved to GPU.
- Some global resources locations have been hardcoded to reduce complexity.
What is missing:
- ~~Workaround for lack of gl_BaseInstanceARB.~~ Done
- ~~Object Uniform Attributes.~~ Done (Not in this patch)
- Workaround for hardware supporting a maximum of 8 SSBO.
Reviewed By: jbakker
Differential Revision: https://developer.blender.org/D15817
