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Thanks! I have some questions about integrating ECS with cross-platform concerns. How did you tackle the problem of components containing geometry for platform

Thanks! I have some questions about integrating ECS with cross-platform concerns. How did you tackle the problem of components containing geometry for platform-specific graphics engines? Does Bevy use platform-specific components? If an application needs multiple offscreen textures to compose a frame, are there components that contain metadata for which passes they belong to (so, now, platform and pass specific components)?

nicoburns 4y ago
Bevy uses wgpu as it's graphics engine, which is cross-platform.
_cart 4y ago
We handle this class of problem in a few different ways: 1. We build on top of cross platform abstractions with feature detection (wgpu is our cross platform low level graphics library, cpal is that for audio, etc). We build our features in a way that adjust the ECS app logic according to what features are available at runtime 2. In a few cases we do "compile time feature/platform detection" to select the appropriate code for a given platform. But most "Bevy features" don't use this / we opt for (1) more than anything else In the case of geometry: that has a "dynamic" representation that can be adjusted according to the platform context (although in practice we don't do any platform-specific geometry transforms yet). And that gets written to the platform's gpu using wgpu. Bevy has a "render graph", which feeds on Bevy ECS data. We adapt the render graph (and the ECS data that drives it) according to the features supported on a given platform.