Basic engine shaders test

This patch adds shader compilation tests for the basic engine in `shaders_test.cc`

Addresses T92701

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D13066

Pointcloud selection support

This patch adds support for selecting pointclouds.

Since pointclouds were not properly drawn to the selection buffer (as diagonsed by output from `glReadPixels` and Renderdoc), they were not able to be selectable by depth picking or occlusion queries. In `basic_engine`, objects were rendered with a shader which draws to a depth buffer but only assumes a single position vertex attribute. Pointclouds, though, require at least another vertex attribute `pos_inst` which provides the instance offsets. Thus, this patch adds another shader variant for pointclouds which supports these two attributes and renders the points appropriately.

{F11652666}

Addresses T92415

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D13059

Pointcloud selection support

This patch adds support for selecting pointclouds.

Since pointclouds were not properly drawn to the selection buffer (as diagonsed by output from `glReadPixels` and Renderdoc), they were not able to be selectable by depth picking or occlusion queries. In `basic_engine`, objects were rendered with a shader which draws to a depth buffer but only assumes a single position vertex attribute. Pointclouds, though, require at least another vertex attribute `pos_inst` which provides the instance offsets. Thus, this patch adds another shader variant for pointclouds which supports these two attributes and renders the points appropriately.

{F11652666}

Addresses T92415

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D13059

Pointcloud selection support

This patch adds support for selecting pointclouds.

Since pointclouds were not properly drawn to the selection buffer (as diagonsed by output from `glReadPixels` and Renderdoc), they were not able to be selectable by depth picking or occlusion queries. In `basic_engine`, objects were rendered with a shader which draws to a depth buffer but only assumes a single position vertex attribute. Pointclouds, though, require at least another vertex attribute `pos_inst` which provides the instance offsets. Thus, this patch adds another shader variant for pointclouds which supports these two attributes and renders the points appropriately.

{F11652666}

Addresses T92415

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D13059

Geometry Nodes: Add Instances to Points Node

This node takes a geometry set with instances as input and outputs
points located on the origins of the top level of instances in the
geometry set (not nested instances). It also has position and radius
inputs to allow overriding the default, and a selection input to only
generate points for some instances.

The use case for this node is a method to use geometry proximity on
instance origins, but in a more generic way that is flexible and useful
in other situations.

Differential Revision: https://developer.blender.org/D12893

Geometry Nodes: Rotate Euler: Use "Local" instead of "Point"

Since points aren't relevant in function nodes, replace all mentions
of it with "local" to illustrate rotations done in local-space instead.

Differential Revision: https://developer.blender.org/D12881

Geometry Nodes: Updated Subdivision Surface Node

Replaces the old Subdivision Surface Node.

Changes:
- Removes implicit instance realization, instead the node runs once
per unique instance.
- "Use Creases" becomes a crease field input applied to edges.
The values are clamped between zero and one.

Addresses T91763

Differential Revision: https://developer.blender.org/D12830

Fix T92102: Issues with align euler to vector node

For fixed pivots, make sure the correct pivot axis is being used.
Also add continues or invalid rotations.

Differential Revision: https://developer.blender.org/D12824

Geometry Nodes: Align Euler to Vector Node

This commit introduces the Align Euler to Vector function node which
rotates to a body into a given direction. The node replaces the legacy
"Align Rotation to Vector" node, which only worked on an attribute
named `rotation` internally. The "Euler" in the name is meant to make
it clearer that the rotation isn't interchangeable with a regular
vector.

Addresses T91374.

Differential Revision: https://developer.blender.org/D12726

Geometry Nodes: Add Rotate Euler Node

This commit introduces the Rotate Euler function node which modifies
an input euler rotation. The node replaces the "Point Rotate" node.

Addresses T91375.

Differential Revision: https://developer.blender.org/D12531