# Objective
Update Bevy to wgpu 0.15.
## Changelog
- Update to wgpu 0.15, wgpu-hal 0.15.1, and naga 0.11
- Users can now use the [DirectX Shader Compiler](https://github.com/microsoft/DirectXShaderCompiler) (DXC) on Windows with DX12 for faster shader compilation and ShaderModel 6.0+ support (requires `dxcompiler.dll` and `dxil.dll`, which are included in DXC downloads from [here](https://github.com/microsoft/DirectXShaderCompiler/releases/latest))
## Migration Guide
### WGSL Top-Level `let` is now `const`
All top level constants are now declared with `const`, catching up with the wgsl spec.
`let` is no longer allowed at the global scope, only within functions.
```diff
-let SOME_CONSTANT = 12.0;
+const SOME_CONSTANT = 12.0;
```
#### `TextureDescriptor` and `SurfaceConfiguration` now requires a `view_formats` field
The new `view_formats` field in the `TextureDescriptor` is used to specify a list of formats the texture can be re-interpreted to in a texture view. Currently only changing srgb-ness is allowed (ex. `Rgba8Unorm` <=> `Rgba8UnormSrgb`). You should set `view_formats` to `&[]` (empty) unless you have a specific reason not to.
#### The DirectX Shader Compiler (DXC) is now supported on DX12
DXC is now the default shader compiler when using the DX12 backend. DXC is Microsoft's replacement for their legacy FXC compiler, and is faster, less buggy, and allows for modern shader features to be used (ShaderModel 6.0+). DXC requires `dxcompiler.dll` and `dxil.dll` to be available, otherwise it will log a warning and fall back to FXC.
You can get `dxcompiler.dll` and `dxil.dll` by downloading the latest release from [Microsoft's DirectXShaderCompiler github repo](https://github.com/microsoft/DirectXShaderCompiler/releases/latest) and copying them into your project's root directory. These must be included when you distribute your Bevy game/app/etc if you plan on supporting the DX12 backend and are using DXC.
`WgpuSettings` now has a `dx12_shader_compiler` field which can be used to choose between either FXC or DXC (if you pass None for the paths for DXC, it will check for the .dlls in the working directory).
# Objective
- shaders defs can now have a `bool` or `int` value
- `#if SHADER_DEF <operator> 3`
- ok if `SHADER_DEF` is defined, has the correct type and pass the comparison
- `==`, `!=`, `>=`, `>`, `<`, `<=` supported
- `#SHADER_DEF` or `#{SHADER_DEF}`
- will be replaced by the value in the shader code
---
## Migration Guide
- replace `shader_defs.push(String::from("NAME"));` by `shader_defs.push("NAME".into());`
- if you used shader def `NO_STORAGE_BUFFERS_SUPPORT`, check how `AVAILABLE_STORAGE_BUFFER_BINDINGS` is now used in Bevy default shaders
# Objective
fixes#5946
## Solution
adjust cluster index calculation for viewport origin.
from reading point 2 of the rasterization algorithm description in https://gpuweb.github.io/gpuweb/#rasterization, it looks like framebuffer space (and so @bulitin(position)) is not meant to be adjusted for viewport origin, so we need to subtract that to get the right cluster index.
- add viewport origin to rust `ExtractedView` and wgsl `View` structs
- subtract from frag coord for cluster index calculation
# Objective
add spotlight support
## Solution / Changelog
- add spotlight angles (inner, outer) to ``PointLight`` struct. emitted light is linearly attenuated from 100% to 0% as angle tends from inner to outer. Direction is taken from the existing transform rotation.
- add spotlight direction (vec3) and angles (f32,f32) to ``GpuPointLight`` struct (60 bytes -> 80 bytes) in ``pbr/render/lights.rs`` and ``mesh_view_bind_group.wgsl``
- reduce no-buffer-support max point light count to 204 due to above
- use spotlight data to attenuate light in ``pbr.wgsl``
- do additional cluster culling on spotlights to minimise cost in ``assign_lights_to_clusters``
- changed one of the lights in the lighting demo to a spotlight
- also added a ``spotlight`` demo - probably not justified but so reviewers can see it more easily
## notes
increasing the size of the GpuPointLight struct on my machine reduces the FPS of ``many_lights -- sphere`` from ~150fps to 140fps.
i thought this was a reasonable tradeoff, and felt better than handling spotlights separately which is possible but would mean introducing a new bind group, refactoring light-assignment code and adding new spotlight-specific code in pbr.wgsl. the FPS impact for smaller numbers of lights should be very small.
the cluster culling strategy reintroduces the cluster aabb code which was recently removed... sorry. the aabb is used to get a cluster bounding sphere, which can then be tested fairly efficiently using the strategy described at the end of https://bartwronski.com/2017/04/13/cull-that-cone/. this works well with roughly cubic clusters (where the cluster z size is close to the same as x/y size), less well for other cases like single Z slice / tiled forward rendering. In the worst case we will end up just keeping the culling of the equivalent point light.
Co-authored-by: François <mockersf@gmail.com>
# Objective
- Builds on top of #4901
- Separate out PBR lighting, shadows, clustered forward, and utils from `pbr.wgsl` as part of making the PBR code more reusable and extensible.
- See #3969 for details.
## Solution
- Add `bevy_pbr::utils`, `bevy_pbr::clustered_forward`, `bevy_pbr::lighting`, `bevy_pbr::shadows` shader imports exposing many shader functions for external use
- Split `PI`, `saturate()`, `hsv2rgb()`, and `random1D()` into `bevy_pbr::utils`
- Split clustered-forward-specific functions into `bevy_pbr::clustered_forward`, including moving the debug visualization code into a `cluster_debug_visualization()` function in that import
- Split PBR lighting functions into `bevy_pbr::lighting`
- Split shadow functions into `bevy_pbr::shadows`
---
## Changelog
- Added: `bevy_pbr::utils`, `bevy_pbr::clustered_forward`, `bevy_pbr::lighting`, `bevy_pbr::shadows` shader imports exposing many shader functions for external use
- Split `PI`, `saturate()`, `hsv2rgb()`, and `random1D()` into `bevy_pbr::utils`
- Split clustered-forward-specific functions into `bevy_pbr::clustered_forward`, including moving the debug visualization code into a `cluster_debug_visualization()` function in that import
- Split PBR lighting functions into `bevy_pbr::lighting`
- Split shadow functions into `bevy_pbr::shadows`
