This cleans up a bit of duplicated code and some confusion about
what was culled and what wasn't.
Now everything is culled based on the given object pointer.
If the object pointer is NULL there is no culling performed.
This is still is a dirty workaround.
Note that we are drawing the whole sets of point multiple times. While this
is ineficient, the main bottleneck is CPU transformation.
Workaround to tranform feedback not working on mac.
On some system it crashes (see T58489) and on some other it outputs
garbage (see T60171).
So instead of using transform feedback we render to a texture,
readback the result to system memory and reupload as VBO data.
It is really not ideal performance wise, but it is the simplest
and the most local workaround that still uses the power of the GPU.
This should fix T59426, T60171 and T58489.
BF-admins agree to remove header information that isn't useful,
to reduce noise.
- BEGIN/END license blocks
Developers should add non license comments as separate comment blocks.
No need for separator text.
- Contributors
This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
Current implementation works with at most of 3 layers, but was not
checked during hair drawing leading to reading from uninitialized
memory.
This commit limits it to the number of layers that is used during
compilation of blender.
This new system use transform feedback to compute subdivided hair points
position. For now no smoothing is done between input points.
This new system decouple the strands data (uv, mcol) with the points
position, requiring less update work if only simulation is running.
In the future, we can have compute shader do the work of the feedback
transform pass since it's really what it's meant to. Also we could generate
the child particles during this pass, releasing some CPU time.
draw_hair.c has been created to handle all of the Shading group creations
as well as subdivision shaders.
We store one final batch per settings combination because multiple viewport
or render could use the same particle system with a different subdivision
count or hair shape type.
