# Objective
Add web support to atmosphere by gating dual source blending and using a
macro to determine the target platform.
The main objective of this PR is to ensure that users of Bevy's
atmosphere feature can also run it in a web-based context where WebGPU
support is enabled.
## Solution
- Make use of the `#[cfg(not(target_arch = "wasm32"))]` macro to gate
the dual source blending, as this is not (yet) supported in web
browsers.
- Rename the function `sample_sun_illuminance` to `sample_sun_radiance`
and move calls out of conditionals to ensure the shader compiles and
runs in both native and web-based contexts.
- Moved the multiplication of the transmittance out when calculating the
sun color, because calling the `sample_sun_illuminance` function was
causing issues in web. Overall this results in cleaner code and more
readable.
## Testing
- Tested by building a wasm target and loading it in a web page with
Vite dev server using `mate-h/bevy-webgpu` repo template.
- Tested the native build with `cargo run --example atmosphere` to
ensure it still works with dual source blending.
---
## Showcase
Screenshots show the atmosphere example running in two different
contexts:
<img width="1281" alt="atmosphere-web-showcase"
src="https://github.com/user-attachments/assets/40b1ee91-89ae-41a6-8189-89630d1ca1a6"
/>
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Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com>
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