It is usually nice to unroll loops with a different number of
iteration based on a macro. This commit adds this functionality
to our shader preprocessor so that we don't have to manually unroll
these loops.
Pull Request: https://projects.blender.org/blender/blender/pulls/146043
These lines can be removed to avoid parsing them.
This allow to keep the same processing for shared host files.
Also removes a few lines of code to reduce the size of
shader sources.
This also contains a rewrite of the include parsing using
the shader parser.
Pull Request: https://projects.blender.org/blender/blender/pulls/146025
Implementation of the design task #142969.
This adds the following:
- Exact GPU interpolation of curves of all types.
- Radius attribute support.
- Cyclic curve support.
- Resolution attribute support.
- New Cylinder hair shape type.

What changed:
- EEVEE doesn't compute random normals for strand hairs anymore. These are considered legacy now.
- EEVEE now have an internal shadow bias to avoid self shadowing on hair.
- Workbench Curves Strip display option is no longer flat and has better shading.
- Legacy Hair particle system evaluates radius at control points before applying additional subdivision. This now matches Cycles.
- Color Attribute Node without a name do not fetch the active color attribute anymore. This now matches Cycles.
Notes:
- This is not 100% matching the CPU implementation for interpolation (see the epsilons in the tests).
- Legacy Hair Particle points is now stored in local space after interpolation.
The new cylinder shape allows for more correct hair shading in workbench and better intersection in EEVEE.
| | Strand | Strip | Cylinder |
| ---- | --- | --- | --- |
| Main |  |  | N/A |
| PR |  |  |  |
| | Strand | Strip | Cylinder |
| ---- | --- | --- | --- |
| Main |  | | N/A |
| PR | ||  |
Cyclic Curve, Mixed curve type, and proper radius support:

Test file for attribute lookup: [test_attribute_lookup.blend](/attachments/1d54dd06-379b-4480-a1c5-96adc1953f77)
Follow Up Tasks:
- Correct full tube segments orientation based on tangent and normal attributes
- Correct V resolution property per object
- More attribute type support (currently only color)
TODO:
- [x] Attribute Loading Changes
- [x] Generic Attributes
- [x] Length Attribute
- [x] Intercept Attribute
- [x] Original Coordinate Attribute
- [x] Cyclic Curves
- [x] Legacy Hair Particle conversion
- [x] Attribute Loading
- [x] Additional Subdivision
- [x] Move some function to generic headers (VertBuf, OffsetIndices)
- [x] Fix default UV/Color attribute assignment
Pull Request: https://projects.blender.org/blender/blender/pulls/143180
This does a few things:
- Add support for templated struct.
- Change parsing of template scope.
Now all template scope `<..>` are parsed properly.
- Rework to support better match syntax.
- Avoid warning from scope guard processing. Now initialize
the return value to zero.
Pull Request: https://projects.blender.org/blender/blender/pulls/145132
This makes the new parser code output correct errors.
Also simplify error logging.
Simplify a few things inside the parser interface.
Add debug string to the `Token` and `Scope`.
Pull Request: https://projects.blender.org/blender/blender/pulls/144708
Use the lately introduced parser for that.
This allows to use preprocessor directive inside them.
By extension, it alows having resource accessors inside
templates.
Also error report is less confusing on most shader compilers.
The counterpart is that the shader files that are shipped
with blender are inflated.
Pull Request: https://projects.blender.org/blender/blender/pulls/144588
Use signed range and indices to avoid dereferencing tokens
before the start of the Token array.
# Conflicts:
# source/blender/gpu/glsl_preprocess/shader_parser.hh
This adds the following features:
- `class` keyword support: checked by C++, mutated to struct for shader.
- `private` and `public` keywords: checked by C++, removed for shader.
- `static` methods.
- `const` and non-const methods.
What is not supported:
- Constructors
- Destructors
- operators
- Method definition outside of class definition
- member reference without `this` keyword.
This is implemented using a very simple lexer/parser allowing semantic traversal.
Pull Request: https://projects.blender.org/blender/blender/pulls/144025